RAID 5 Rebuild Time?

First, this is the first RAID array I've ever set up, I chose RAID 5 to get the most out of the 4, 1TB, WD RE3's that I am using. Also I am using the Intel RAID utility that is built in to my MOBO, an ASUS P6X58D Premium. This is a new build so I am not married to the current set up and can change it based on recommendations from folks in this forum.

Here's what's going on; I finished my build and after making sure the basics were stable I added a RAID array (Corsair 800D using all 4 'hot swap' bays). After adding the HDD's I booted the machine and used the Intel RAID utility to set up a 4 HDD RAID 5. This worked well for about 24 hours. I had time to put about 93Gig of info on the RAID array.

Yesterday when I booted the machine the POST screen only saw 3 of the 4 drives, OK, I pulled the offending drive, tested it, it had failed so I put in the spare that I bought for just such an occasion. As soon as I booted the RAID utility asked me to identify the replacement drive as a member of the Array and off it went 'rebuilding'. That was 24 hours ago and it's still at it.

Is this unusual?

Like I said, I'm new at this and I thought it would only take a few hours to rebuild. While it is rebuilding I am doing nothing with machine just letting it chew on the rebuild process.

Here are my primary questions:

Repeating above: Is this an unusual amount of time for only 93 GIG of data?
What would happen if I have to reboot? (power failure) Does it start over?
If I have to abandon this set up and start over are the drives toast? (kind of a part two of above)
And finally how can you tell the progress of the rebuild? Or, is it even possible to find out?

FYI: to keep things simple I used the 4 SATA 3Gbs ports on the MOBO (0,1,2,3) and set up the bays from top to bottom (0 on top, 3 on the bottom)

I appreciate any help or wisdom you all can provide.
3 answers Last reply
More about raid rebuild time
  1. Yes, it takes a long time to rebuilt.

    The raid that you're using it's a FAKE raid (linux term). It is a software raid or hardware assist raid. There is no dedicates IOP to control the raid engine but rather use the host CPU.

    I would highly recommend not to use this type of raid if you want performance.

    This type is good for back up only (low cost), consider a hardware raid if you could.

    For 5x-drive-hardware-raid-controller.html, It is an excellent hardware raid controller that does not require any drivers, all it needs is a SATA port or any hardware raid controller
  2. For those of you who are checking this thread for information here is what I discovered, keeping in mind that I'm using the 'Intel Matrix Storage Utility' that was included in the BIOS of my P6X58D Premium MOBO and I did not set this up as a bootable RAID.

    1. Intel has a small utility called "Intel Rapid Storage Technology". It can be downloaded for free from here;

    (current version, file name = iata_cd.exe)

    2. This utility will tell you just what is going on with your RAID/s.

    3. After I loaded it it told me where I was in the rebuilding process (% complete) and the array that was being rebuilt. (It continues to monitor the health of my RAIDs.)

    4. It took 41 hours to rebuild.

    5. Rebooting the machine made no difference, the rebuild process picked up where it left off and nothing happened to the drives.

    6. For some reason I was not getting the full advantage of the RAID 5. I chose this because with a RAID 5 using 4 1Tb drives I should get about 2.8Tb of storage but the system would only recognize 1.9Tb and put the rest into 'unalocated space'. I can only assume this is a Win 7 limitation as the Intel Matrix software had no problem with the size.

    In any event I ended up deleting the single RAID 5 and setting up 2 RAID 1 (mirror) arrays which gave me more flexibility and about the same storage space and it is a bit faster.

    I hope this info is helpful to anyone with the same questions.

    Some info about my machine:
    ASUS P6X58D Premium MOBO
    i7 980x
    12 Gig corsair RAM
    Radeon HD5870 x 2 in CrossFire
    1000w PSU
    Win 7 Home Premium 64

    Finally, thanks to FireWire2 for the info but I'm going to stick with what I have.
  3. carolinacorky

    6- Your system seeing 1.9TB and the rest is unallocate, because the volume being partition as MBR instead of GPT. MBR only sees up to 2.0TB, where GTP can see 256TB capacity.

    Base on what you posted 4TB rebuilt 41HRS, or 1TB/h, or 27.7MB/sec - This is way too slow, I don't think the RAID1 would give you much improvement

    With all the good hardware that you invested you system will run as fast as the slowest component...

    I highly recommend to upgrade to hardware raid, it will be 10x as fast
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