Mac Pro RAID Card - RAID 5 capacity with 4 drives

Greetings everyone,
last weekend, I installed a Mac Pro RAID card in my Mac Pro, gave it 4 Samsung 1TB disks to play with and set up a RAID 5 array on it. However, the capacity is less than what I would have expected (expected around 2.8TB and got 2.38TB).
After some searching on the Apple Support pages, I found this ...
http://docs.info.apple.com/article.html?artnum=306212
... support article stating that in a 4 column RAID 5, the capacity indeed could be less than expected due to "data placement and layout techiques".
Does anyone know the technical reason behind this? Any other RAID 5 I know, hardware or otherwise, does not have this quirk.
Is there any way to work around this? If not, are there any other, comparable RAID cards that get this right?
Thanks in advance,
-sai

Hi sairath;
With RAID 5 one of the drive is devoted to Parity so that the data can be restored in case of a drive failure. Hence you are only going to see the space for three of the drive so your results sound pretty normal.
Allan

Similar Messages

MAC PRO (Early 2008) RAID CARD ISSUE - SYSTEM FREEZEHello (hopefully someone can shed some light on my issue) I own as above a MAC PRO (Early 2008) this has a RAID card installed along with two 15k.7 cheetah hdd (320gb) and a spare drive, (which i m

Hello (hopefully someone can shed some light on my issue)
I own as above a MAC PRO (Early 2008) this has a RAID card installed along with two 15k.7 cheetah hdd (320gb) and a spare drive, (which i made a regular drive)
a while ago i had to replace the RAID card battery, so i did this, over a year later the same thing happened again, but as previous just left it and the system seemed fine for ages, until last night i was working in PHOTOSHOP and everything just froze and the screen kind of appeared GREEN, could not do a single thing. So restarted the mac, this time grey screen for ages and a message appeared, (macs version of blue screen) (see attached).
I restarted the machine and this time a flashing question mark folder!
could not do a thing.
so i found my copy of snow leopard and got the computer to run this and at least launch the DISK UTILITY and (Interestingly in the drop down menu RAID UTILITY was also in the menu) but it did not matter which utility i used the (RAID or DISK) neither could see any of drives, just the dvd drive.
so looked around on you tube and various forums and discovered if i take out the RAID CARD and re-plug the main lead from the RAID card back in to the LOGIC BOARD I would be reverting the MAC to a normal regular non-RAID computer.
After performing this HARDWARE task and inserting all three HDD, and running the DISK utility from the drop down menu via the SNOW LEOPARD disc.
(interestingly since the RAID card had been removed the RAID UTILITY from the drop down menu no longer appeared). running disk utility I can now only see the regular (spare) hdd and DVD Drive, but the two RAID HDD , again, still do not show up DISK UTILITY?
O.K. so i could chuck out the RAID card (AND RAID HDD) and just go with a regular set-up, and run a back restore from Time Machine on a NEW hdd purchased.
but what is wrong with the RAID, is the card at fault or are both HDD used for the RAID knackered? can i perform any tests, to see whats what?
thanks for your help in advanced.

hello people, the issue was in fact the GRAPHICS card nothing to do with the HDD or RAID system ( although this did cause issues with the RAID system it basically lost its way) below is my replay to another similar problem some one else had!
working in photoshop and then everything stopped working and the lot froze! only option was to force shutdown (via button).
and try to restart, hoping all was fine, this was not the case :-(
I had the added issue of the RAID card system, that i have, this was confused to say the lease and would not behave or work, causing the start up to hang.
so i thought the HDD must be bust and the root cause. ( but soon learnt it was not the cause )
...bought a new HDD removed the RAID card and replugged the cable from RAID card into LOGIC board, ( making the computer act like any normal non-RAID system). I managed to install the OSX, using the snow leopard disk way. once the mac was running, i started to notice the screen would flicker and started to see 'artefacts'. so i started to reveal my symptoms to the web and forums and soon discovered that my graphics card could be the issue all along?.
(nvidia geforce 8800gt 2x dvi).
I read up on that a fix, could be either A. reply the thermal paste, as the card could be over heating or B. stick the card in the oven trick.
Tried option A. first and nothing still issues, so last night took the plunge carried out option B. and ta da it worked! i even managed to run
from my new HDD my lasted install OS X, absolutely fine. I then thought, maybe i could repair my RAID so replugged all the HARDWARD back in and
carried out a disk repair and disk permissions on drives( took a small amount of time), via the SNOW LEOPARD disc - (Disk utilities) and this worked and now have my system working as it was just over 6 days ago.
what was the cost to get this? bought a new hdd so 40.00gbp and thermal paste and cleaner kit ( your still need to do this ) search video card trick on you tube.
and renew thermal paste, approx 15.00gbp, technically i don't need the new HDD, but it was all part of the trial and error way i went. ( i do have extra storage as a result!)"

I have a mac pro 1.1. the main hard drive failed. How do I reload OS X 10.7 back in my computer. the app store will not let me reinstall this os. My computer is not compatible OS x 10.8?

I have a mac pro 1.1. the main hard drive failed. How do I reload OS X 10.7 back in my computer. the app store will not let me reinstall this os. My computer is not compatible OS x 10.8?

You need to first install the OS your Mac came on the bundled gray disks. Assuming it's Snow Leopard, you could then login into the App Store using your same Apple ID and password to download and install Lion.
If your Mac is a bit older and came with Leopard, 10.5.x, you can bypass that and install Snow Leopard from your retail disk. The only software you'd need to install separately from the gray disks would be the optional software, such as the iLife suite and other titles not included on the retail SL disk.

Thunderbolt update V1.2 is not supported on my system: Mac Pro 12 Cores (mid 2012) with Mac OSX 10.8.3

I'm trying to connect an external 8 Tera thunderbolt hard drive to my Mac Pro 12 Cores (mid 2012) with Mac OSX 10.8.3, and it is not recognizad, so I tried to make the thunderbolt upgrade V1.2, and a windows appears and says: "this software is not supported on my system"
Please tell me waht to do.
thanks a lot.

Thunderbolt is a revolutionary I/O technology that supports high-resolution displays andhigh-performance data devices through a single, compact port. It sets new standards for speed, flexibility, and simplicity. And it’s on MacBook Air, MacBook Pro, iMac, and Mac mini.
I don't see mention of the Mac Pro.

Convert a Mac Pro Server from January 2007 with OS 10.4 Server to Snow Leopard 6.0 (NON SERVER)

I have a Mac Pro Server from January 2007 with OS 10.4 Server installed. I want to convert from OS 10 Server OS to just using Snow Leopard 6.0 (NON SERVER). I have two hard drives installed. What is the best way to do this?
Can I just install Snow Leopard NON-SERVER on the second drive, then switch it into the place of the original main drive?
Can I switch the drives, then install the Snow Leopard on the replacement drive?

Not sure how you configured the server, though you can install snow leopard on second HDD and select boot drive with pressing "option" key during startup.

Mac Pro airport card boot issues

I've taken an old airport card from a Mac Mini, and installed it in an Early 2009 Mac Pro.
The unit should be fully compatible, but when I boot, it just hangs at the 50% mark on the startup screen.
If I remove the card, the machine boots just fine.
Is there a firmware update I need to make to the system, to tell it about the new wireless card?

What makes yo think it is compatible? It seems not to be.
Also these do not list a Mini card being compatible with a Mac Pro desktop card
http://eshop.macsales.com/item/Apple/AR5BXB112/
http://eshop.macsales.com/item/Apple/6615048K/

Mac Pro Graphics Cards

I am using an early Mac Pro 3 GHz Dual-Core Intel Xeon with an NVIDIA GeForce 7300 GT Graphics Card. I am thinking of upgrading my monitor to a 24" model with high resolution.
Can anyone give me advice on whether I need, or could benefit from, a new Graphics Card?
Any advice would be most appreciated.
YAGOM

The NVIDIA GeForce 7300 GT graphics card has one dual-link DVI port that can handle a display up to 2560 x 1600, and one single-link DVI port that can handle up to 1920 x 1200, so unless you need more graphics speed, such as for games, you don't need a new graphics card.
Note: there is currently no way to use the new Apple 24" LED display with any Mac Pro graphics card.

I would like to display what's on my Mac Pro monitor on my iPad with as little latency as possible. What's the best way to do this?

I would like to display what's on my Mac Pro monitor on my iPad with as little latency as possible. What's the best way to do this?

Your image history (if I understand you properly) is stored in your catalog file, and nowhere else, and so it is only on a single drive.
Do you mean you have edited photos on multiple drives? This isn't a problem for Lightroom at all, the software doesn't care, and you can leave things just the way they are. But if it bothers you for some reason, you can move the photos to a single drive if you want. In Lightroom select the desired photos or folders (it's easier to do this using Folders) and drag them to the desired drive.
Alternative if you will be moving lots of folders: Adobe Lightroom - Find moved or missing files and folders

Mac Pro video card in a PM G5 dual 2.0?????

Will the stock Mac Pro video card: NVIDIA GeForce 7300 GT, work in a PowerMac G5 Duallie 2.0 (mid 2004 model) with the pci-x slots? Thankx! And would a Cube G4 Rage 128 video card work in thePM G5? (I bought a G5 without a video card and I need to test it and find a cheap video card for it). Thx again!

No. It is PCI Express card anyway.
head over to OWC and look there www.macsales.com

Can I buy a Mac Pro in the U.S., with a German keyboard?

can I buy a Mac Pro in the U.S., with a German keyboard?

The Mac Pro Tower is NOT a laptop computer. It weighs 65 lbs, and holds four full-size Hard Drives. It uses a detachable keyboard.
US English
Western Spanish
French
Japanese
... are readily available at the Apple Online Store, in wired and wireless.
For German, you would have to call them and make special arrangements, or pick one up an additional keyboard when you get back home.
This thing won't fit in your suitcase. Are you sure you want to pay to ship it home again? I would be tempted to sell it when you are leaving, and buy a new one at Home.
A laptop would be a better choice. These are also available with the same four choices of languages (in all models) through the online store.
You can make all the German characters and accents with the USEnglish keyboard, but some are two keystrokes.

My Mac Pro only has a 250GB hard drive. can I use my 1TB hard drive from my windows computer, they're bith SATA

my Mac Pro only has a 250GB hard drive. can I use my 1TB hard drive from my windows computer, they're bith SATA

You want system, data, backup etc. Make good use of the four internal drive bays.
You will have to use Disk Utility to ERASE or click on drive and use PARTITION to make it Mac writeable.

How do you new Mac Pro owners like your machine with Logic?

Don't mean to be a PITA but I need to get this right before I drop three to five grand on a new set of music tools. I'm trying to decide between Mac Pro and iMac for use with Logic. Seems there are a lot of posts regarding glitches with the new Mac Pro and Logic, whereas the posts from people with older G4s and G5s seem to indicate they are running rock solid. So you new Mac Pro folks or anyone else, please weigh in. Is the new Mac Pro "glitch heavy" or is it just a matter of tweaking the system to where it runs smooth? In general, how do you new Mac Pro folks like the way it works with Logic?

I'm mostly pleased with my MacPro 2.66. Almost no crashes with Logic, although I experience a few more bugs here and there than with my G4. Occasional CoreAudio errors, I have to restart CoreAudio if my external word clock is set to the wrong sample rate when I open a session, there seems to be a bug between high fader levels (above +4dB) and panning... little things like that.
Then again, compared to my G4, the FireWire bus is screaming fast--with most sessions, I can run a buffer of 128 samples at 96k with my MOTU 828mkII, while my G4 would sometimes glitch at 96k with 512 samples. At 96k, 256 samples, my MacPro/828mkII rig is rock-solid... I informally tested it by recording 12 test tracks simultaneously for 20 minutes, with the CPU nearly maxed out (which was difficult to do--took a bunch of Space Designers and Ultrabeats)--absolutely zero clicks or pops.
And of course, WAY more processing power than my G4.
I'm assuming that MacPro compatibility is a fairly high priority for Apple these days, so hopefully the bugs will get worked out soon. And as things are, Logic is definitely usable on a MacPro--the bugs I encounter rarely slow down my work.
So, far from perfect, but as far as new technology goes, I'd say Logic on the MacPro is above average.
Good luck!
James
[email protected]

My new Mac will not allow the download of CS5, how do i circumvent this issue? I own th dvd however my Mac Pro does not have a disc drive.

My new Mac will not allow the download of CS5, how do i circumvent this issue? I own th dvd however my Mac Pro does not have a disc drive.

Download from Download CS5 products

I downloaded a game modern combat for my i mac pro but its not applicable with my mac

i downloaded a game modern combat for my i mac pro but its not applicable with my mac.Do i get refund or what i suppose to do .

Limnos wrote:
This is a computer game? That's a Mac App Store issue, not an iTunes issue (the forum in which you posted)
It is an iOS app in the iTunes store.

Apps store icon no longer available, book shelf will no longer access the store, and my mac pro will not sinc apps with my iPad. What's up?? How do I correct? This is after upgrading to iOS6 and Mountain Lion.

Apps store icon no longer available, book shelf will no longer access the store, and my mac pro will not sinc apps with my iPad. What's up?? How do I correct? This is after upgrading to iOS6 and Mountain Lion.

Saw this on another post.
Applecare Senior Advisor Txx Bxxx (I have his contact info in an email he just sent) just confirmed with me that the problem people are having with the App Store not loading is an apple issue with there servers, ITS NOT YOUR IPAD so don't go restoring it! It's not happening to everyone however but they are looking into it, its really hit or miss.
In the meantime ...........
The Complete Guide to Using the iTunes Store
http://www.ilounge.com/index.php/articles/comments/the-complete-guide-to-using-t he-itunes-store/
Can't connect to the iTunes Store
http://support.apple.com/kb/TS1368
iTunes: Advanced iTunes Store troubleshooting
http://support.apple.com/kb/TS3297
Best Fixes for ‘Cannot Connect to iTunes Store’ Errors
http://ipadinsight.com/ipad-tips-tricks/best-fixes-for-cannot-connect-to-itunes- store-errors/
Try this first - Reset the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons.
This works for some users. Not sure why.
Go to Settings>General>Date and Time> Set Automatically>Off. Set the date ahead by about a year.Then see if you can connect to the store.
 Cheers, Tom

Mac Pro RAID Card - RAID 5 capacity with 4 drives

Similar Messages

Maybe you are looking for