Software RAID-1 with two different drives

Hi,
I got a 2 TB Seagate Barracuda, which I am looking to mirror in a RAID-1 set-up. Now, since the space is filling rather fast, I suspect I'll have to keep adding disks to this machine in the future. So, I have a interest in changing to some low power (since its always on) drives.
So, I'm thinking of making the second disk a 2 TB Seagate NAS drive (and then use NAS drives from this point on), which is a fair bit slower than the main drive. Personally, I wouldn't expect this to be a problem at all, but I thought it would be best to check with others first though
Have anybody here tried running a RAID-1 where one disk is considerably slower than the other? Will this give any issues (other than the speed being limited by the slower disk)?

WonderWoofy wrote:
The speed will certainly be limited by the slowest device, as you mentioned, but what I am confused about is what you expect to achieve by continually adding drives to a RAID-1? At some point, do you plan on changing the RAID level? Because RAID-1 is mirroring. If you add another drive, you will not get more space, you will just get another copy of your data... and another... and another.
I'm not sure that btrfs would be any easier in this case, as the mdadm tools are pretty robust and certainly allow for adding and removing drives. But if you use btrfs it might actually be beneficial if you are set on keeping a RAID-1 type setup. This is because btrfs' raid levels are not quite like traditional raid. If you put your btrfs array in a RAID-1 setup with two disks, it is no different. But when you add another disk, it will continue to keep just two copies. So if you have a total of four disks, then it will still be only two copies of any given data, meaning that you will end up with twice the space of the two disk RAID-1.
Maybe you are thinking of a different RAID level altogether? If speed is not the issue but you care about redundancy and fault tolerance, then you might want to look into RAID-5 or RAID-6, though these require quite a few disks.
Ello',
I'm continuously going to be adding drivers to the machine, not to the same raid-1 array. My plan is once space gets tight, I'll add another disk and bump it up to raid-5

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Raid 1 with two external drives

Hi Everyone,
I've been searching for some answers on this and havent quite found what ive been looking for so i figured id just ask. I have two identical 1tb g-drives daisy chained and hooked up to my imac via Firewire 800. I want to make one of the drives raid 1 to mirror all the information on the other. What is the best way to go about doing this?
I was also wondering would it be better just to have time machine do backups of one drive onto the other? any advantages/disadvantages to either method?
Thanks in advance everyone!
Cheers,
Scott

scotty morrison wrote:
These drives will be used to store Masters and dailies from photo and video shoots and well as the final edits from those shoots, so id qualify them as "mission critical".
Instead of "making" your own RAID1 array, you may want to investigate some "turn-key" RAID solutions. For example [this one at Macsales|http://eshop.macsales.com/shop/Mercury-EliteAL-Pro-RAID]. (That's just one RAID1 turn-key unit that Macsales has.)
Since you mention video, perhaps even consider RAID5 for more capacity, or RAID10 pr RAID0+1 for higher speeds. RAID0 would be good for the edits "scratch space", but not for any "real" storage. Thus the use of RAID10 or 0+1. (If you really want to get the max performance, do some research on the differences between 10 & 0+1.)
...Im now thinking however that i should have my masters in raid1 and on separate drives have my live edits being backed up by time machine as they change. Would this be a good thing to do?
Again, RAID1 is not a backup, so regardless of where you have the "masters", they should be backed up. With the backup, you can then recover from a loss of a drive, it will just be a little more time to get running again compared to RAID1. Thus the "need" for RAID1 is debatable for the masters and final edits, etc.
Also realize that RAID1 & RAID5 generally have slower performance than an individual drive (or RAID0) due to the overhead of writing the mirror or parity info. In many "workstations", they have a individual drive to boot from, then a RAID0 array for the editing "scratch space", and the final version of the file on some other storage. (i.e.: RAID5 SAN.)
Be careful with reliance on Time Machine for backups. Time Machine is good, but sometimes Time Machine can't backup files that are in use. (e.g.: [iPhoto|http://support.apple.com/kb/HT4116].) This is true of most backup systems unless you get some really expensive software so for something you're considering "mission critical" like these video files, I'd be looking at an additional backup system. (Even something as lowly as manually copying files to an external hard drive or an Automator workflow.)
To give another perspective: RAID1 if you absolutely can't have this system down for even one second. Which means your boot drive needs RAID1. Your "scratch space" on RAID0 or a SSD, since you want speed and can deal with the loss of a drive. Your "masters" & "final edits", you need to consider _+long term+_ storage. (a.k.a.: archiving.) The largest hard drives currently are 3TB. Being video, I'm going to guess you'll out grow this quickly. With RAID1, you'd be "stuck" at 3TB until larger hard drives come out...and then you've have to buy two of them...then be "stuck" again. So IMHO you should be looking at a RAID5 system that can grow. They can be "slower" RAID5 since you're looking at long term storage rather than max performance like the scratch disks. (If you need a little more performance, then RAID10, but you'd be sacrificing capacity.) For example, the 8 or 16 drive Drobo. Start with 2 or 3 drives now, then add more drives as needed. Drobo's of this capacity aren't cheap, but if they are as "mission critical" as you think they are, then a Drobo or similar is probably a worthwhile investment. But really, it appears to me that a proper backup procedure of your masters/final edits would be sufficient. RAID1 then is just icing-on-the-cake, albeit, very good icing.

RAID with two USB drives?

I just bought two USB drives (2 x WD 3 TB MyBook Essential) and tried to set them up as mirrored RAID on my Mac Mini (Mid 2010 model, OS X 10.7) using Disk Utility. It lets me do all the configuration (pick disks, etc.) but when I hit create, I get the following error:
POSIX reports: The operation couldn't be completed. Operation not permitted.
Is there any way to solve this / explanation why this happens?

Here is an app that should do what you are looking for.
http://qgf.in/BBRBMh
that will take you to a shareware page at apple.com. The software lets you compare two different drives and select which way you want the changes to go.
It is shareware so you should be able to try it out before you buy it. Make sure it does what you want.
Another option is Chronosync http://qgf.in/PLfpeu . It is a little pricey, but it works well.
Message was edited by: D0GG

Dual boot setup with two hard drives

Hi all, I've searched through the forums but haven't been able to find an answer to what I figure is a couple pretty easy questions.
My wife has an older G4(circa 2000) with OS 9.2.x on it now. What I would like to do is put a new, larger HD in the box and install Tiger on it. I've found write-ups talking about installing Tiger and OS 9.x.x on different drives or on the same drive in different partitions. My problem is I still am not sure how you switch between Tiger/OS9 with two different drives. Is Tiger able to recognize the OS9 on a different drive and allow you to easily switch back and forth like it does when they are installed on the same drive?
My second question is hopefully even easier. Can I head on over to my local computer supply store and pick up any old ATA HD like I would for a *Nix/Windows box or am I forced to get one directly from apple like I had to with a bad power supply?
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OK, here's mine for comparison:
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finderinfo[0]: 3040 => Blessed System Folder is /Volumes/OS9.2/System Folder
finderinfo[1]: 0 => No Startup App folder (ignored anyway)
finderinfo[2]: 0 => Open-folder linked list empty
finderinfo[3]: 3040 => OS 9 blessed folder is /Volumes/OS9.2/System Folder
finderinfo[4]: 0 => Unused field unset
finderinfo[5]: 0 => No OS 9 + X blessed X folder
64-bit VSDB volume id: 0x233F23EAA912CD05So it would appear this might be the problem, since you don't have a "OS 9 blessed folder".
Now, I have never had to do this, but have seen it work for others. The bless command has a lot of options, many of which we don't want here. But let's give this a try. Remember, copy and paste this command into a text editor (TextEdit will do). Then edit the command to put your volume name in it (in place of <yourvolumename>, without the angle brackets), and copy and paste again into Terminal.
You will need to be logged in to an 'admin' account:
sudo bless -folder9 /Volumes/<yourvolumename>/System\ Folder/Press return and you will be prompted for your password. This is not echoed for security reasons: just type it and press return.
Then, if you get no complaints, I would issue a
rebootcommand. Your OS 9 System Folder should now be available to you in your Classic preferences screen.
Let us know how this goes!

My boyfriend and I have each an IPhone with two different Apple IDs. Since the recent software his contacts appears in my Iphone. How can I switch that off? I have be looking at both Iphones and Iclouds.

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Trying to setup RAID 1 with new SATA drives on xserve 2009 model
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Can Time Machine Backup to Two Different Drives?

I have many Apple Computers, and I was wondering if it were possible to have time machine backup to two different drives.
I want it to back up My documents, Mail, and other files/folders that I access often to a partition of my internal drive every minute.
And
I want it to back up Everything on my Mac to my external each night upon connecting it to my mac.
I take my MacBook everywhere with me and I need to make sure that the files I work on the most stay Perfectly Accessible no matter what, and I don't want to sacrifice too much space for that procedure. I would rather just be able to do constant backups of my most used files and folders, and then do a system backup each night to make sure I always have what is needed.

Let me add some more observations. I use two disks, one at home (its a mounted volume on another Mac at home) and the other is a portable disk that I attach to my MBP at work. This works fine.
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Set up itunes account with two different credit cards

Is it possible to set up an existing iTunes Store Account with two different credit cards?
I am currently registered with a personal card but wish to make one purchase for work (Lion OS) using a company credit card.
many other sites let you choose what card to pay from, multiple addresses, etc. but I don't see any options from apple site.
for this purchase I am considering:
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2. editing all the info related to the company card and address.
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the_0ne wrote:
but this discussion is clearly for people that have multiple accounts because they have multiple credit cards.
This is incorrect.
It is very clearly for people with a single iTunes account and they want to use multiple credit cards for purchases on that single iTunes account.
If I had one iTunes account with multiple credit cards registered (which again, is what this discussion is in reference to),
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You mean your company paid for it. You are simply the one who did the purchasing using company funds.
I now have a new iMac of which I want to install Lion. Apple allows you to install this same install multiple times on your own personal machines. I had to remember which account I bought Lion on so that I logged into the App Store correctly. If I would have logged into my new iMac with my personal account, I would have then bought Lion again, of which I didn't want to do.
But you did not purchase Lion with your personal account. It was purchased on your business account.
If you want Lion on your persona/home computers, you will need to purchase it.
I also wanted to install iPhoto. I bought iPhoto on my personal account. I had to then log out of the app store from my company account and log back in using my personal account to install iPhoto or I would have just bought iPhoto with my company's credit card, of which I would have been in a good amount of trouble.
Imagine if I bought 3 or 4 apps a week and these apps were scattered across my business account and my personal account. Each time I wanted to install these apps on one of my multiple machines in my house, I would have to remember which account I bought the app on. or go to my purchases or which there could possibly be dozens of apps in each account.
I would hope that your company requires you to track purchases you have made with their money.
And I would think that you would want to keep track of all business purchases so you can get reimbursed (for the purchases you made on their behalf). If/when you leave the company, they can get company owned software that you purchased with their funds.

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I use this block in my vis.
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Dear gtu,
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Hi,
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Charliy,
No the both dates are from two different databases, tables and fields. The Credit date field is from KLAB database under max table where as the FOC date field is from SAE database under maxmast table. Klab date is under credit2 table where as foc date is under order header table.
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two dates totally different tables, dbs
however, I will try your idea too and see if that works.
Regards
Jehanzeb

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