2 Filled Sonnet Fusion 500P enclosures; RAID 0/1, or RAID 5?

I currently have a Sonnet Fusion 500P loaded with 5 WD 500GB RE2 drives; all running individually and not RAIDed; this box is connected to a Sonnet Tempo E2P in my MacPro.
I'm interested in getting a 2nd identical enclosure and drives, and creating a RAID system using 10 drives. I also plan on upgrading the E2P to the E4P, since it will provide increased RAID performance that the E2P does not.
I've been reading the various posts on RAID on these forums, and also have looked through the AMUG articles and reviews, and I have a couple of questions.
First, can I stripe the 5 drives in each enclosure, and then mirror the two enclosures? This RAID setup will be used for Final Cut Pro capture and editing, and also for DVD Studio Pro files. Basically, I would have 2.5TB of high speed storage, and a duplicate of that.
Second question-can I do this with Disk Utility, or would I need additional software/hardware to accomplish it?
And finally, I'm a little vague about RAID 5 setups, but would it be better to create a RAID 5 with one enclosure and 5 drives, using 4 for storage and one for parity information? From my limited knowledge of this, I think that if the RAID 5 failed, it could be rebuilt using the info on the 5th drive? Is this correct?
What would be the best way to go here, taking into account the hardware I already have? If I'm off base, I'm open to suggestions for a different setup that would have comparable storage space, speed, and backup.
Thanks for any advice anyone can give.

Dear Mike,
It sounds like you want more RAID capabilities than Disk Utility can easily provide. Since you are looking for a new host adapter card anyway, you might as well get one that can provide RAID 0, 1, 5 and 1/0. I would suggest the HighPoint RocketRAID 2314 if you want to stay with individual eSATA cables. The AMUG review can be found here:
http://www.amug.org/amug-web/html/amug/reviews/articles/highpoint/2314/
If you would rather have a card with a single cable and do not mind purchasing an extra cable, I really like the HighPoint RocketRAID 2314MS which is the same card with a different cable system. Here is that AMUG review and a link to the cable you would need:
http://www.amug.org/amug-web/html/amug/reviews/articles/highpoint/2314ms/
http://www.amazon.com/exec/obidos/ASIN/B000JQ51CM/arizomacinusergr
The Sonnet E4P is a good card but it cannot support RAID 5, 10 or 50 and the HighPoint cards can.
The HighPoint cards also provide just as good or better performance with a 10 drive SATA PM configuration like the one you are considering.
It sounds like the main reason for the second SATA PM enclosure is mainly backup. Please understand that a RAID 5, 10 or 50 configuration adds redundancy to your hard disk array but it is not a guarantee that you will recover from directory corruption or user errors. If the directory is corrupted on a RAID 10 it can easily write the same corrupted data on the mirror copy of the drive.
If you truly want a backup, I would consider using SuperDuper or Carbon Copy Cloner at the end of each day to backup the work on the first SATA PM RAID to the RAID in the 2nd SATA PM enclosure. Having your backup off-line when not in use is the best way to be ensure the backup data will be intact when you need it.
Have fun!

Similar Messages

PCIe eSATA Sonnet + Fusion 500p

I am planning on getting the Sonnet e4P SATA card and the Fusion 500p expansion enclosure. I like the features of the enclosure and quietness. However i am aware that going direct connect is typically faster than using Port Multiplication when the drives are <80% full. Is anyone using this rig and is anyone getting it to run direct connected in any way ?

Hate to bump this, i will let it wither if no responses.

Setting Up Dual Sonnet Fusion/WD RE2 RAID 0 Arrays in Disk Utility

I've just received my 2nd Sonnet Fusion 500P enclosure, 5 500GB WD RE2s, and the Sonnet Tempo E4P card. See this earlier thread for more info:
[http://discussions.apple.com/thread.jspa?messageID=6034612&#6034612]
I assembled everything with no trouble; drives into trays, trays into the enclosure, card into the Mac Pro, etc.; all went well.
Next, in Disk Utility I initialized the 5 drives, and set up a striped RAID O array. I used the largest RAID block size of 256K. And again, everything worked perfectly; I now have a 2.3 TB RAID setup mounted on my desktop.
Next, I created 2 folders on the RAID, one for all of my Final Cut Pro media files, and another for all my DVD Studio Pro media files. These files are currently stored on the individual (not RAIDed) drives in my first Sonnet Fusion enclosure. I'm now in the process of copying over all of the files to the new RAID.
When that's finished, my plan is this: I will shut down, and power down the original Sonnet enclosure. When I start up again, one by one, I will open up my FCP and DVDSP projects (the project files themselves are stored on my internal boot drive, and backed up to another internal drive) and when the media can't be found, I'll reconnect the project to the media on the RAID.
If this all goes well, I will then erase the individual drives in the first enclosure, and build a 2nd RAID 0; I'll copy/clone everything from the first RAID enclosure to the 2nd.
If you're still reading, does this sound like a safe way to do things? I want to reconnect everything while I still have 2 copies of all of the media files; once I have the 2nd RAID built, and everything is copied back to it, I'll have a backup of everything again. If there is a better, more secure way to do it, I'm open to suggestions.
And being somewhat new to RAID, one more question I have is, are drives in a RAID system more prone to failure than if they are running as stand-alone drives? I've used the WD RE2s a lot, and I like them; they seem very reliable. (I now have 14 of them, in total). But does the RAID system itself put the drives more at risk?
Thanks to those with the patience to read through this, and hopefully offer some advice.

Always have two backups or sets of data. If you are going to erase one set... then for a stretch of time you only have the one good copy I take it? I guess the originals would be one good set, so you are safe.
You realize you can unmount drives connected on Sonnet controllers, right? No need to shutdown your computer, just the enclosure(s). Couldn't tell if that is what you said anyway.
I don't use internal drives for backups, just external SATA and at least one on FireWire. One backup is always off line at any time. And enough juice on the UPS to carry me through what I am doing or can safely get past.
I just read one of AMUG/michael's post on a controller that supports hardware RAID and ability to map out bad sectors "on the fly" which is about the only time I worry about a failure. That, and UPS, and beware of OS patches and updates (one security update affected SeriTek on some G4/5s).
I'd say you've done a lot for being new to RAID - and using the same make/model/revision for all your drives helps a lot. Buying together, and having at least one 'spare' if one fails, is also good insurance.
Some poeple use 4 drives in a 5-drive enclosure. For heat and ventilation and because sometimes it might be ideal for performance. Never used or seen the 500P up close but I suspect it is well built.
You could build a 2nd 500P and either increase performance or capacity or use 2nd as backup. If you don't need to copy 1GB per minute, then a concatenated RAID fills drive A before putting data on B and is more secure than a stripped RAID but still shows up as one large volume.

New, larger drives for Sonnet Fusion RAIDs

Hello-
I got some great advice here a couple of years ago in regards to building my two 5-drive RAID systems with Sonnet Fusion 500Ps and WD RE2 500GB enterprise drives. They have performed flawlessly, and I've never had a single glitch. (They are connected to my 2006 MacPro and are used almost exclusively for video capture).
Now, however, I'm in need of more storage; I want to either add a 3rd enclosure (I'm considering the FirmTek SeriTek 5-bay enclosure) or replace the 500GB drives I have with larger ones. Perhaps eventually I'll do both; I have a Sonnet E4P with two SATA ports still available.
Either way, I'm looking for larger drive recommendations for these boxes. I use a striped RAID 1 configuration for the 500Ps I have, and then backup/clone one box to the other.
I've been considering the WD 1.0TB Caviar Black Enterprise drives, but I might want to go with 1.5TB drives, such as the Seagate 7200.11. The price on these is right, but I've heard that early versions of this model had problems in RAID configurations; it's also not a 5 yr. warranty/enterprise class drive.
Any suggestions? I got valuable help last time from mbean and hatter; perhaps they will contribute again, but I'd appreciate any advice I can get before purchasing 10 new drives, or 5 additional drives and a new enclosure.

Thanks for the reply and the recommendation. The Samsung is pretty new; I wonder how reliable it is. MacSales (OWC) has a Samsung 1TB model HD103UJ (The U replaces the S) and it is more expensive.
Hi,
The Samsung F1 HD103UJ is the older model. AMUG has 18 of these that were used in RAID tests for the last year. They are a great HD - but for blazing speed the new Samsung F3 model HD103SJ is the next replacement and about 20% faster.
I have never found "Enterprise" hard disks worth the extra money. The reason is that most standard hard disks will reliably last 3 years and the enterprise versions are almost never faster than the standard version they were developed from. After 3 years all of my hard disks are ancient technology.
Three years ago the hot hard drive to own was a 300GB with 65MB/sec performance. We thought that was great. Now its in the junk heap or delegated to backup duty on a notebook
Hard disk technology is increasing much faster than most of us can keep up with and prices are very reasonable for new 1TB hard disks. Sure there will be a few buyers who think they need to pay the 2TB premium but most users will wait until these hard disks are under $130.
Buying hard disks at premium prices can be painful especially when you realize that a new set will probably be required every 3 years.
Have fun!

Port Multiplication: Sonnet Fusion 400 vs 500P

I spend a lot of time on the Bare Feats website. I really appreciate what Rob has done and the tests he performs. Sometimes I have a little trouble interpreting his results, but maybe that's just me. Anyhow he has done some tests of 500 GB drives and the new PCIe SATA controller from Sonnet. Can anyone give me a feel as to the performance differences in some real world setups. Assuming using the same drives (a 500 GB WD or Hitachi for instance)how will perfomance compare:
Internal controller SATA I vs Sonnet SATA II controller and a single drive in a Fusion 400 enclosure.
A single drive in a Fusion 400 vs a single drive in a 500P.
Raid 0 in a full Fusion 400 vs a full 500P.

Anyhow he has done some tests of 500 GB drives and
the new PCIe SATA controller from Sonnet. Can anyone
give me a feel as to the performance differences in
some real world setups. Assuming using the same
drives (a 500 GB WD or Hitachi for instance)how will
perfomance compare:
The WD 500 will perform faster than the Hitachi 500 in single drive uses whether it is installed in the PowerMac G5 dual-core internal bay or in a Fusion 500P port multiplier enclosure.
A 5 drive SATA PM enclosure will provide about 200MB/sec
performance using an E4P and a dual-core or Quad PowerMac G5. 10 drives will provide about 400MB/sec and so on. You can see very detailed performance charts and comparisons in the AMUG Sonnet E4P review found here:
http://www.amug.org/amug-web/html/amug/reviews/articles/sonnet/e4p/
Internal controller SATA I vs Sonnet SATA II
controller and a single drive in a Fusion 400
enclosure.
No SATA I controllers exist for the Dual-core Qual except the internal PowerMac G5 interface. All PCIe SATA cards are SATA II. SATA II cards will perform a little faster but typically within 5% difference for an individual drive.
A single drive in a Fusion 400 vs a single drive in a
500P.
Raid 0 in a full Fusion 400 vs a full 500P.
A single drive in a Fusion 400 direct connect enclosure will perform at about the same speed as the same drive in a Fusion 500P.
The limitation of SATA PM is the sharing of a single cable for all data. Typically, writes are limited to 200MB/sec on a PCIe PowerMac and 227MB/sec on a PCI-X PowerMac.
A four drive Fusion 400 can do 270MB/sec using Maxtor SATA II hard drives. A 500P SATA PM solution will provide about 20-25% less speed when empty but will provide nice performance when full.
You might also want to see the AMUG Addonics 5X1 eSATA review as these PM enclosures perform about the same. Both of them use the Silicon Image 3726 PM chip.
http://www.amug.org/amug-web/html/amug/reviews/articles/addonics/5x1/
Between these two articles you will find plenty of details to answer your questions.
Hope this helps,
Michael

Uncompres10bit HD w/ Sonnet Fusion D500P

anyone using 2 Fusion D500P enclosures raid together at raid0 to get 10bitHD capture & playback? I have 2 of those connect to sonnet 4ep sata card (**** caldigit ran out of their card so I have to use sonnet).
anyhow, raid 2 boxes together at raid0 doesn't work for me. I'm using the seagate enterprise 1TB drives (10 of them) but somehow during capture or Render long sequence the boxes just goes offline.
so, I raid only 1 box w/ 5drives & it can capture proRES(HQ) HD but sometimes the boxes goes offline too but better than 2 boxes together. I thought more is better but not. Called sonnet & they said it has to do w/the drives not the box so i'm thinking of swaping the new drives from owc.
any suggestion? can't afford their D800P box. trying to cut corner here.
J

Drives went offline would be caused by:
1. hard drive.
2. sonnet e4p driver.
3. your system or FCP.
4. Unreliable software RAID setting.
I am not sure if one fusion d500p with sonnet e4p can handle 10bit uncompress? it's slower than the requirement and not sustained.
Getting 2 fusion d500p and sonnet card and 10 drives and dealing with software stripe through disk utility is no fun at all, with the same price tag with no significant additional costs, you actually can buy just one single Caldigit HDOne or cheaper & smaller HDelement to do 10bitHD capture & playback, and they are all hardware RAID so more reliable than os stripe.

Conversion of ad20 non raid to a D20 raid 1 and keeping existing OS/data

I have a new D20 with windows 7-x64 pre installed on it. I purchased a second Lenovo supplied sata add in drive to convert the system to raid 1.
When I add the “raid 1” in support in the bios, the system when it reboots does not recognize the existing windows 7 partition.
When I used “other mfg” on board raid configuration, the working partition was considered the master partition and was automatically mirrored to the new added drive (making it raid1)
My expectation was that there would be either a “thinkvantage” tool that allowed you to do this from the OS, or there would be a some OS add on tool that performs this function
So my question.. Can you convert a d20 non raid to a D20 raid 1 (given drives are the same etc), and if so (I am a glass half full person), what is the process required to do so.
thanks
matt k.

if the marvell RAID controller hasn't been enabled, you'll need to install the driver. it can be found here: http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-73697
after this is installed, boot into the D20 BIOS and enable RAID. reboot again into the unconfigured drive and see if you can get into windows. if so, you can set up your RAID 1 array.
if you want to control RAID configuration from within windows, you'll need to install the marvell RAID utility found here: http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-73073
(edit: typo)
ThinkStation C20
ThinkPad X1C · X220 · X60T · s30 · 600

Raid S-ata,ide,raid 0,1,0+1 and io in general

I've got a bunch of questions I wanna ask so i suppose the apt thing to do on a forum like this would be to put them in priority lol.
1. I remember somebody saying that 2 raid arrays, one being raid 0 and the other being identical and used to mirror the first is impossible. Can someone tell me why and if not how to set it up?
- (I Have had Delayed Write Failure problems under XP(ectin' OSmethin' better), but I'm fairly sure I caused this by changing and fixing the page file size and forcing the machine not to page system files.)
2. There seems to be a bit of a divide as to the value of the promise controller, I would like some hard facts and first hand experiences.
3. Can both the promise and via controllers be used for seperate raid arrays and if so could one be S-ATA and the other be IDE or do they have to be homogenous?
4. If I Choose to go with a different version of raid, say 1, or 0+1 what sort of performance difference is there from raid 0 and for that matter from each other?
5. I'm pretty sure I read somewhere that the promise controller can handle four disks in an array - could this be true?
6. Somebody mentioned that the VIA raid solution was only a software solution, is this true and if so how much CPU overhead could I Expect.
7. Any other disk related performance or redundacy advice would regarding these controllers etc. would be appreciated.
8. Sorry about the length of this post people.

well i am no expert but i'll attemp to answer your q's
1. a windows delayed write error can be from cacheing your hard drives go to device
manager, (rt click my computer) hardware,device manager,
disk drives ,properties, policies, un check optimise for performance.
2. the promise can run a sata array and a ide array, or can combine them into one big array, with the reduced performance of the ide drives.
3. stripped or raid 0 is the fastest, especialy if your a gamer and set it up with smaller clusters, say 32k. raid 1 is mirrored, or a duplicate copy of your hard drive and is only good if your drive fails, it does nothing for corupt windows, or installs, or viruses, it is a copy, (i use norton ghost to make drive images at various stages for backups, to combat virus, and corupt installs that destroy windows.
4.you could backup a stripped array ,but when you strip ann array say two 120 gig hard drives it creates one big 240. that is why i partioned mine into two 120s, so i could ghost them. (which i feel is better then a mirror.
5. speed, when i had my system disk on ide1 it tranfered at 36 mb/sec when i put them on ide3 raid 0 128k cluster(better for large files, like photoshop) it increased to 65 mb/sec...nearly double.
6. i oc and ide oc's better then sata, so i stuck with ide and a fsb of 222.
hope that helps, and if anyone would like to add plz do

Moving from VIA RAID controller to another RAID controller?!?

Hello
I'm going to install a RAID-1 with 2 SATA harddisks from seagate using the onboard VT8237 RAID controller of my KT6 Delta.
I guess there should be no problems and that the temperature on the motherboard will be fine.
However, what will happen if I want to move later on to a new motherboard with another raid controller or install a dedicated RAID controller?!?
Will I loose all my data? Or will the new raid controller duplicate the data based on the source drive?
Thanks
JohnQM

I have read somewhere that the following migration paths apply for raid:
1. raid-1 can always be migrated to a new RAID controller, no matter which brand, because raid-1 is just a mirror and no important information is written in the partition table
2. raid-0 or other raid-levels
2.0 from one brand of RAID controller to the same version of the RAID controller of the same brand: no problem
2.1 from one brand of RAID controller to a new version of the RAID controller of the same brand: usually no problem (upwards compatible)
2.1 from one brand of RAID controller to a RAID controller of another brand: no go
Can someone confirm this please?
Thanks
JohnQM

OS drive + RAID 1 with Apple RAID card

I have a G5 Xserve with the RAID card and three ADM drives. How do I set up Megaraid to have a single non-raid drive and a RAID 1 mirror? I installed the OS onto one of the drives after a "destroyconfig". When I create the RAID with drives 1 and 2, the drive 0 is lost. THe only way I found to make it work was with a soft RAID 1 in disk utility.

How do I set up Megaraid to have a single non-raid drive and a RAID 1 mirror?
I'd go with not connecting one of the drives to the RAID card.
When you installed the card you replaced three short SATA cables with three long ones - one per drive.
Just replace one of the long ones with one of the original short ones. This will reconnect one of the drives back to the motherboard, leaving two drives connected to the RAID card.
Kind of a hack, for sure, but in lieu of having a JBOD mode in megaraid it seems like the simplest solution.

No RAID support, even hardware raid on the enclosure level

According to a report from XLR8Yourmac.com, a customer bought an Airport Extreme (n) basestation but was unable to have their RAID enclosure recognized. Instead, only one drive shows up instead of two, and is unreadable. Applecare told him that even hardware RAID needs to be supported at the driver level for the unit, and they didn't think the Extreme had enough horsepower to do it. I question this, since you can attach RAID enclosures to computers so old, they are less powerful computers than the n basestation.
This is very bad news for me, as I have two 1TB RAIDs (OWC Mercury Elite Pro 800/400/USB2 SATA RAID enclosures) that I was going to attach to the new extreme, but now, I'm not buying one at all...

OK, thank you. That's exactly my status. And since this machine is very slow and has only around 1GB of memory (minus memory for the GPU!), a swap partition seems pretty important - and be it only for hibernating.
For the records: I recently thought about trying out a swap file on a dedicated non-journaled partition (ext2 f.ex.) mounted with nodiscard. I don't know how much performance I would lose or if hibernating really works flawlessly. But since I'm now using a different harddrive for the netbook and it's running, I don't want to setup everything again at the moment. If anybody tries the swap file variant, it would be nice to report back in this thread :-)

Time Machine back up filling with Fusion 2.0.1 Boot Camp virtual machine

Hi all, I want to report and share something (don't actually know if it's a bug).
I finally solved an issue that was maddening me since weeks: my Leopard 10.5.6 Time Machine was backing up lots of gigabytes of data even if I wasn't writing to files that much lately. I tried to exclude everything I was aware of having a large size, and I even did not have a Fusion VM at all at a certain point in */Users/MyUser/Documents/Virtual Machines*. The only virtual machine I am using is the virtualized Bootcamp partition with Vista installed. But I didn't care about it because I was sure Time Machine wasn't going to backup it (i.e. I thought it was excluded by default being another partition!). Instead, I finally succeded in tracking down (with a free app called "Time Tracker", google for it) the culprit to a *Boot Camp partition.vmwarevm* file, several gigabytes large (actually large as much as the used space in the Boot Camp partition), that's found under
*/Users/MyUser/Library/Application Support/VMware Fusion/Virtual Machines/Boot Camp/%2Fdev%2Fdisk0*
So I went in Time Machine options dialog and excluded */Users/MyUser/Library/Application Support/VMware Fusion/Virtual Machines/Boot Camp*.
Then the problem was solved...now I need only to mount the sparsebundle and erase all the old backups of that file to recover some more space in Time Capsule...
Hopefully this will be helpful to someone else!
Cheers!

AppleRyck wrote:
Hi all, I want to report and share something (don't actually know if it's a bug).
I finally solved an issue that was maddening me since weeks: my Leopard 10.5.6 Time Machine was backing up lots of gigabytes of data even if I wasn't writing to files that much lately. I tried to exclude everything I was aware of having a large size, and I even did not have a Fusion VM at all at a certain point in */Users/MyUser/Documents/Virtual Machines*. The only virtual machine I am using is the virtualized Bootcamp partition with Vista installed. But I didn't care about it because I was sure Time Machine wasn't going to backup it (i.e. I thought it was excluded by default being another partition!).
No, not a bug. By default TM will back-up any drive/partition it can read, except the TM backup drive/partition itself.

To RAID or not to RAID, that is the question

People often ask: Should I raid my disks?
The question is simple, unfortunately the answer is not. So here I'm going to give you another guide to help you decide when a raid array is advantageous and how to go about it. Notice that this guide also applies to SSD's, with the expection of the parts about mechanical failure.
What is a RAID?
RAID is the acronym for "Redundant Array of Inexpensive Disks". The concept originated at the University of Berkely in 1987 and was intended to create large storage capacity with smaller disks without the need for very expensive and reliable disks, that were very expensive at that time, often a tenfold of smaller disks. Today prices of hard disks have fallen so much that it often is more attractive to buy a single 1 TB disk than two 500 GB disks. That is the reason that today RAID is often described as "Redundant Array of Independent Disks".
The idea behind RAID is to have a number of disks co-operate in such a way that it looks like one big disk. Note that 'Spanning' is not in any way comparable to RAID, it is just a way, like inverse partitioning, to extend the base partition to use multiple disks, without changing the method of reading and writing to that extended partition.
Why use a RAID?
Now with these lower disks prices today, why would a video editor consider a raid array? There are two reasons:
1. Redundancy (or security)
2. Performance
Notice that it can be a combination of both reasons, it is not an 'either/or' reason.
Does a video editor need RAID?
No, if the above two reasons, redundancy and performance are not relevant. Yes if either or both reasons are relevant.
Re 1. Redundancy
Every mechanical disk will eventually fail, sometimes on the first day of use, sometimes only after several years of usage. When that happens, all data on that disk are lost and the only solution is to get a new disk and recreate the data from a backup (if you have one) or through tedious and time-consuming work. If that does not bother you and you can spare the time to recreate the data that were lost, then redundancy is not an issue for you. Keep in mind that disk failures often occur at inconvenient moments, on a weekend when the shops are closed and you can't get a replacement disk, or when you have a tight deadline.
Re 2. Performance
Opponents of RAID will often say that any modern disk is fast enough for video editing and they are right, but only to a certain extent. As fill rates of disks go up, performance goes down, sometimes by 50%. As the number of disk activities on the disk go up , like accessing (reading or writing) pagefile, media cache, previews, media, project file, output file, performance goes down the drain. The more tracks you have in your project, the more strain is put on your disk. 10 tracks require 10 times the bandwidth of a single track. The more applications you have open, the more your pagefile is used. This is especially apparent on systems with limited memory.
The following chart shows how fill rates on a single disk will impact performance:
Remember that I said previously the idea behind RAID is to have a number of disks co-operate in such a way that it looks like one big disk. That means a RAID will not fill up as fast as a single disk and not experience the same performance degradation.
RAID basics
Now that we have established the reasons why people may consider RAID, let's have a look at some of the basics.
Single or Multiple?
There are three methods to configure a RAID array: mirroring, striping and parity check. These are called levels and levels are subdivided in single or multiple levels, depending on the method used. A single level RAID0 is striping only and a multiple level RAID15 is a combination of mirroring (1) and parity check (5). Multiple levels are designated by combining two single levels, like a multiple RAID10, which is a combination of single level RAID0 with a single level RAID1.
Hardware or Software?
The difference is quite simple: hardware RAID controllers have their own processor and usually their own cache. Software RAID controllers use the CPU and the RAM on the motherboard. Hardware controllers are faster but also more expensive. For RAID levels without parity check like Raid0, Raid1 and Raid10 software controllers are quite good with a fast PC.
The common Promise and Highpoint cards are all software controllers that (mis)use the CPU and RAM memory. Real hardware RAID controllers all use their own IOP (I/O Processor) and cache (ever wondered why these hardware controllers are expensive?).
There are two kinds of software RAID's. One is controlled by the BIOS/drivers (like Promise/Highpoint) and the other is solely OS dependent. The first kind can be booted from, the second one can only be accessed after the OS has started. In performance terms they do not differ significantly.
For the technically inclined: Cluster size, Block size and Chunk size
In short: Cluster size applies to the partition and Block or Stripe size applies to the array.
With a cluster size of 4 KB, data are distributed across the partition in 4 KB parts. Suppose you have a 10 KB file, three full clusters will be occupied: 4 KB - 4 KB - 2 KB. The remaining 2 KB is called slackspace and can not be used by other files. With a block size (stripe) of 64 KB, data are distributed across the array disks in 64 KB parts. Suppose you have a 200 KB file, the first part of 64 KB is located on disk A, the second 64 KB is located on disk B, the third 64 KB is located on disk C and the remaining 8 KB on disk D. Here there is no slackspace, because the block size is subdivided into clusters. When working with audio/video material a large block size is faster than smaller block size. Working with smaller files a smaller block size is preferred.
Sometimes you have an option to set 'Chunk size', depending on the controller. It is the minimal size of a data request from the controller to a disk in the array and only useful when striping is used. Suppose you have a block size of 16 KB and you want to read a 1 MB file. The controller needs to read 64 times a block of 16 KB. With a chunk size of 32 KB the first two blocks will be read from the first disk, the next two blocks from the next disk, and so on. If the chunk size is 128 KB. the first 8 blocks will be read from the first disk, the next 8 block from the second disk, etcetera. Smaller chunks are advisable with smaller filer, larger chunks are better for larger (audio/video) files.
RAID Levels
For a full explanation of various RAID levels, look here: http://www.acnc.com/04_01_00/html
What are the benefits of each RAID level for video editing and what are the risks and benefits of each level to help you achieve better redundancy and/or better performance? I will try to summarize them below.
RAID0
The Band AID of RAID. There is no redundancy! There is a risk of losing all data that is a multiplier of the number of disks in the array. A 2 disk array carries twice the risk over a single disk, a X disk array carries X times the risk of losing it all.
A RAID0 is perfectly OK for data that you will not worry about if you lose them. Like pagefile, media cache, previews or rendered files. It may be a hassle if you have media files on it, because it requires recapturing, but not the end-of-the-world. It will be disastrous for project files.
Performance wise a RAID0 is almost X times as fast as a single disk, X being the number of disks in the array.
RAID1
The RAID level for the paranoid. It gives no performance gain whatsoever. It gives you redundancy, at the cost of a disk. If you are meticulous about backups and make them all the time, RAID1 may be a better solution, because you can never forget to make a backup, you can restore instantly. Remember backups require a disk as well. This RAID1 level can only be advised for the C drive IMO if you do not have any trust in the reliability of modern-day disks. It is of no use for video editing.
RAID3
The RAID level for video editors. There is redundancy! There is only a small performance hit when rebuilding an array after a disk failure due to the dedicated parity disk. There is quite a perfomance gain achieveable, but the drawback is that it requires a hardware controller from Areca. You could do worse, but apart from it being the Rolls-Royce amongst the hardware controllers, it is expensive like the car.
Performance wise it will achieve around 85% (X-1) on reads and 60% (X-1) on writes over a single disk with X being the number of disks in the array. So with a 6 disk array in RAID3, you get around 0.85x (6-1) = 425% the performance of a single disk on reads and 300% on writes.
RAID5 & RAID6
The RAID level for non-video applications with distributed parity. This makes for a somewhat severe hit in performance in case of a disk failure. The double parity in RAID6 makes it ideal for NAS applications.
The performance gain is slightly lower than with a RAID3. RAID6 requires a dedicated hardware controller, RAID5 can be run on a software controller but the CPU overhead negates to a large extent the performance gain.
RAID10
The RAID level for paranoids in a hurry. It delivers the same redundancy as RAID 1, but since it is a multilevel RAID, combined with a RAID0, delivers twice the performance of a single disk at four times the cost, apart from the controller. The main advantage is that you can have two disk failures at the same time without losing data, but what are the chances of that happening?
RAID30, 50 & 60
Just striped arrays of RAID 3, 5 or 6 which doubles the speed while keeping redundancy at the same level.
EXTRAS
RAID level 0 is striping, RAID level 1 is mirroring and RAID levels 3, 5 & 6 are parity check methods. For parity check methods, dedicated controllers offer the possibility of defining a hot-spare disk. A hot-spare disk is an extra disk that does not belong to the array, but is instantly available to take over from a failed disk in the array. Suppose you have a 6 disk RAID3 array with a single hot-spare disk and assume one disk fails. What happens? The data on the failed disk can be reconstructed in the background, while you keep working with negligeable impact on performance, to the hot-spare. In mere minutes your system is back at the performance level you were before the disk failure. Sometime later you take out the failed drive, replace it for a new drive and define that as the new hot-spare.
As stated earlier, dedicated hardware controllers use their own IOP and their own cache instead of using the memory on the mobo. The larger the cache on the controller, the better the performance, but the main benefits of cache memory are when handling random R+W activities. For sequential activities, like with video editing it does not pay to use more than 2 GB of cache maximum.
REDUNDANCY(or security)
Not using RAID entails the risk of a drive failing and losing all data. The same applies to using RAID0 (or better said AID0), only multiplied by the number of disks in the array.
RAID1 or 10 overcomes that risk by offering a mirror, an instant backup in case of failure at high cost.
RAID3, 5 or 6 offers protection for disk failure by reconstructing the lost data in the background (1 disk for RAID3 & 5, 2 disks for RAID6) while continuing your work. This is even enhanced by the use of hot-spares (a double assurance).
PERFORMANCE
RAID0 offers the best performance increase over a single disk, followed by RAID3, then RAID5 amd finally RAID6. RAID1 does not offer any performance increase.
Hardware RAID controllers offer the best performance and the best options (like adjustable block/stripe size and hot-spares), but they are costly.
SUMMARY
If you only have 3 or 4 disks in total, forget about RAID. Set them up as individual disks, or the better alternative, get more disks for better redundancy and better performance. What does it cost today to buy an extra disk when compared to the downtime you have when a single disk fails?
If you have room for at least 4 or more disks, apart from the OS disk, consider a RAID3 if you have an Areca controller, otherwise consider a RAID5.
If you have even more disks, consider a multilevel array by striping a parity check array to form a RAID30, 50 or 60.
If you can afford the investment get an Areca controller with battery backup module (BBM) and 2 GB of cache. Avoid as much as possible the use of software raids, especially under Windows if you can.
RAID, if properly configured will give you added redundancy (or security) to protect you from disk failure while you can continue working and will give you increased performance.
Look carefully at this chart to see what a properly configured RAID can do to performance and compare it to the earlier single disk chart to see the performance difference, while taking into consideration that you can have one disks (in each array) fail at the same time without data loss:
Hope this helps in deciding whether RAID is worthwhile for you.
WARNING: If you have a power outage without a UPS, all bets are off.
A power outage can destroy the contents of all your disks if you don't have a proper UPS. A BBM may not be sufficient to help in that case.

Harm,
thanks for your comment.
Your understanding was absolutely right.
Sorry my mistake its QNAP 639 PRO, populated with 5 1TB, one is empty.
So for my understanding, in my configuration you suggest NOT to use RAID-0. Im not willing to have more drives in my workstation becouse if my projekts are finished, i archiv on QNAP or archiv on other external drive.
My only intention is to have as much speed and as much performance as possible during developing a projekt
BTW QNAP i also use as media-center in combination with Sony PS3 to run the encoded files.
For my final understanding:
C: i understand
D: i understand
E and F: does it mean, when i create a projekt on E, all my captured and project-used MPEG - files should be situated in F? Or which media in F you mean?
Following your suggestions in want to rebulid Harms-Best Vista64-Benchmark comp to reach maximum speed and performance. Can i use in general the those hardware components (exept so many HD drives and exept Areca raid controller ) in my drive configuration C to F. Or would you suggest some changings in my situation?

To RAID or not to RAID: 4Tb Mac Pro Server

Hi,
Hope someone can steer in the right direction.
I've got a Mac Pro Server. It has 4 x 1Tb HDs and a 6TB Drobo S for backup. It has a RAID card.
My query is, as I need at least 2Tb space instantly to store Final Cut Pro files, etc. Won't be using the server to actually edit anything, or any other tasks.
a) Do I set up RAID and get only approx. 2TB of usable space - therefore filling it up straightaway
b) Leave it as 4 separate 1Tb harddrives (to get most space)and let the Drobo do its BeyondRAID thing? (At the moment the data is all a Mac and on single Firewire external drives).
c) If I go RAID (it's brand new so I'm at the setup stage). Which is the best option for me?
d) If I do RAID, should I partition 100gb on drive 1, for OSX and programs, etc and then RAID the rest? I guess that means I have to reinstall the whole system? Or can I 'live' partition on a Mac these days?
The Mac Server is a fairly temp solution as we're getting a proper SANs this year, but at present the data lives on a Mac tower (with MyStudio backup drive) and also on a few Firewire drives.
HELP!
Many thanks.

1. With only 4 drives, raid 5 should be fine. That gives 3TB (1TB for redundancy).
2. A backup is more important than raid.
3. The raid setup for the san can be tricky. Depending on the size, you may not want raid 5, but 50, or 6. Consider: A 16TB raid 5 array will need to read all bits CORRECTLY to rebuild a failed raid 5 array. What is the bit error rate of modern disks? Approximately 1 bit for 16TB-20TB of data. So a large raid 5 san may fail to rebuild. Got a backup? This is why they created raid 6.
4. I would setup an extra partition, maybe 100GB, on the raid array. Why? I find it handy, if you need to check the disks, you can reboot from that 100GB partition and check the big partition. Also, you can have 2 different versions of the os on the raid array. You will find this useful, when a update comes out that breaks some things, you can run off the older os and you don't have to live with the broken functionality.

RAID slower than no-RAID

I work on HUGE photshop files, and over the years in these forums, people have called me CRAZY for not working from RAID, but from regular hard drives. I finally upgraded, after much much research. Got the seritek 5mp with five of the new 1TB samsung hard drives, as these were according to OWC MUCH faster than other hard drives ("no comparison", sales parson said). I got a rocketraid card and set up the 5 drives to a eSATA 4TB RAID. I just timed opening a 10GB photoshop file from the RAID vs from the seagate startup disk. The RAID 5 is 20 seconds SLOWER with a psd file than opening from a non-raid hard drive, and with an uncompressed Tiff it's about 5 seconds slower! I now realize it's slower because RAID 5 requires all these calculations to go on. So what is the huge hoolabalooba about the RAID 5? and the samsung drives show no faster speed over any of my other internal drives....
My question now is: Am I better off, just doing a JBOD? I could then move the drives around as I want, and occasionally bring copies off-site for even safer backup than RAID 5 provides? could I then also plug these off-site drives into a docking station attached to my home computer and access my files from there? I know I can't currently do that with the RAID5....

Is there any difference in speed when it comes to an internal RAID 0 set by "disk utility" vs, an external RAID 0 attached to a RocketRaid portmultiplier esata card?
That depends on the card. There are multiple RocketRAID cards and ways to configure them. For example, you could use the actual RAID controller on the card, or you could use JBOD mode and still use Disk Utility to setup and manage the RAID.
If the specific RocketRAID card you're using is setup to manage RAID then you will typically gain a performance edge - the OS only has to dump data to the card and let the card work out the RAID component. If using Disk Utility then the OS has to do the RAID work.
Can a RAID 0 set up by disk utility be moved between different computers?
Yes. All the RAID data is stored on the drives, so as long as all drives are available the array should come up on another machine. I wouldn't recommend this as a matter of course, though - there's always an inherent risk in moving drives from one system to another.
If so, this is my new solution for fast storage/continuous backup/keeping a mirrored copy of everything at home
I'm not quite seeing your vision. You talk about RAID 0, but go on to refer to 'a mirrored copy'...?
Given your second paragraph, you're proposing to periodically swap out three internal drives with three others? I wouldn't recommend this at all. It would be far better, in my opinion, to purchase a multi-disk drive enclosure and just use the external device for your Time Machine backup - it's far easier to unplug a FireWire and/or eSATA enclosure and take that home than it is to repeatedly swap out internal drives.

2 Filled Sonnet Fusion 500P enclosures; RAID 0/1, or RAID 5?

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