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Billy T
03-08-2011, 12:12 PM
Hi Team

I had a spontaneous RAID 1 drive rebuild this morning, following a hard reboot necessitated by my booting while the mouse and keyboard were connected to my old W2K machine via the KVM switch. :(

This event is making me a little nervous because I don't have a spare disk at present. Computer Lounge owes me a warranty replacement after the most recent failure, and there are no problems with that aspect, but apparently they can't get WD640GB Caviar Black drives anymore.

So, am I right in thinking that a RAID 1 drive can be replaced by any other drive of the same or larger capacity? In a RAID 1 (mirrored) system it shouldn't make any difference and the Help file in the RAID console seems to confirm that.

However (there is always a catch with computers) what would happen if say the smaller (and older) of the two drives had a hiccup like this morning?

Would the larger drive still be able to restore to the older smaller drive? If not, I might need to replace both disks at the same time to ensure equal capacity is maintained.

Cheers

Billy 8-{)

inphinity
03-08-2011, 12:35 PM
Many raid controllers will accept different sized drives, and the requirement is only that the drive have sufficient space to hold the required partition size.

Alex B
03-08-2011, 01:05 PM
Software Raid/ motherboard built in RAID controllers are crap, I'd use shadow protect desktop edition if I was you and do incremental backups during the day.

GameJunkie
03-08-2011, 01:06 PM
wouldnt one of those WD green drives be a better solution for you, arent they more reliable than the black drives??

Billy T
03-08-2011, 01:21 PM
Software Raid/ motherboard built in RAID controllers are crap, I'd use shadow protect desktop edition if I was you and do incremental backups during the day.

Thanks, but no thanks, I prefer the RAID 1 system that keeps me up to date and any other back-up program but Shadow Protect! I tried to understand its instructions, and I'm not dumb, but it was way too complex and expensive for my needs. There are other programs for incremental backups that seem to be much simpler to use.

Cheers

Billy 8-{)

SolMiester
03-08-2011, 02:15 PM
Hi Team

I had a spontaneous RAID 1 drive rebuild this morning, following a hard reboot necessitated by my booting while the mouse and keyboard were connected to my old W2K machine via the KVM switch. :(

This event is making me a little nervous because I don't have a spare disk at present. Computer Lounge owes me a warranty replacement after the most recent failure, and there are no problems with that aspect, but apparently they can't get WD640GB Caviar Black drives anymore.

So, am I right in thinking that a RAID 1 drive can be replaced by any other drive of the same or larger capacity? In a RAID 1 (mirrored) system it shouldn't make any difference and the Help file in the RAID console seems to confirm that.

However (there is always a catch with computers) what would happen if say the smaller (and older) of the two drives had a hiccup like this morning?

Would the larger drive still be able to restore to the older smaller drive? If not, I might need to replace both disks at the same time to ensure equal capacity is maintained.

Cheers

Billy 8-{)

The size of the RAID array is created when you 1st build it, whether of 2 different sizes or not....If a smaller drive fails, the array will not increase to the size of the larger, so would have no problem rebuilding a smaller drive as long as its big enough for the array size

SolMiester
03-08-2011, 02:17 PM
wouldnt one of those WD green drives be a better solution for you, arent they more reliable than the black drives??

You are NOT supposed to use green drives in ANY raid array period. They are not built for it....and it even stipulates it on WD website....

I wouldnt use black drives either, the most reliable are the blue drives.

Alex B
03-08-2011, 02:22 PM
Thanks, but no thanks, I prefer the RAID 1 system that keeps me up to date and any other back-up program but Shadow Protect! I tried to understand its instructions, and I'm not dumb, but it was way too complex and expensive for my needs. There are other programs for incremental backups that seem to be much simpler to use.

Cheers

Billy 8-{)


Can't say I found it that complex. (this is the desktop edition im talking about.).

The idea of RAID1 is great, but only if you have a proper RAID controller, otherwise IME they are simply not reliable.

wainuitech
03-08-2011, 02:53 PM
but apparently they can't get WD640GB Caviar Black drives anymore.
That would be right - you can get 500MB, 1GB or 2GB.

Why use blacks anyway -- as you are fully aware, they have a HIGH failure rate, and are not really designed for a RAID setup. While they will work, they are extremely unreliable. As Sol suggested the Blues are far more reliable. But once again, not really designed for a RAID setup.

You would be far better off, and have more reliability with the sightly more expensive RAID edition drives, available in These sizes (http://www.imagef1.net.nz/upload/Raid_Drives.jpg) (cant be bothered writing all that out :) )

inphinity
03-08-2011, 03:10 PM
wouldnt one of those WD green drives be a better solution for you, arent they more reliable than the black drives??

WD Green + RAID = BADDD, it does NOT mix well at all with their variable-speed eco crap.

nedkelly
03-08-2011, 07:43 PM
Sorry to jump in but I was thinking about raiding some Greens, so it is not recommended?
Best to spend twice as much and get the Raid edition drives Wainui said?

inphinity
03-08-2011, 08:57 PM
Sorry to jump in but I was thinking about raiding some Greens, so it is not recommended?
Best to spend twice as much and get the Raid edition drives Wainui said?

The WD Green drives have exhibited an extraordinarily high rate of array failures (not drive failures) caused by differing drives spinning up/down at different times. Your array will constantly be degraded and rebuilding. Personally I would either use Seagate Barracudas, or Seagate or WD's enterprise-grade drives.

GameJunkie
03-08-2011, 09:03 PM
how are the enterprise driver different from the black/green drives etc?

inphinity
03-08-2011, 09:07 PM
how are the enterprise driver different from the black/green drives etc?

The main issue with the green drives is their variable rotation speed, which leads to a drastic variation in their seek and read/write performance, so you get drives out of sync.

The black's are just high failure rate overall. The Blues aren't so bad, but WD do not support them in a RAID config, which leads me to suspect they've found some issues, though I've never personally had a problem with these models.

Billy T
04-08-2011, 12:06 AM
Why use blacks anyway -- as you are fully aware, they have a HIGH failure rate, and are not really designed for a RAID setup. While they will work, they are extremely unreliable. As Sol suggested the Blues are far more reliable. But once again, not really designed for a RAID setup.

You would be far better off, and have more reliability with the sightly more expensive RAID edition drives, available in These sizes (http://www.imagef1.net.nz/upload/Raid_Drives.jpg) (cant be bothered writing all that out :) )

I use Blacks because that is what was installed when it was built. I know nothing of WD-B drive unreliability per-se, but I do know from extensive research that the WD Caviar-Black 640GB does respond badly to issues in one release of the Intel RAID controller software (the one that I have). According to many users on the Intel forum, they perform faultlessly with the earlier and later versions.

I'm not sure why exactly there would be any reliability problem with WD-Blk 640 in RAID 1. As drive usage goes, I can think of no reason why RAID-1 (mirroring) would be any more demanding than operating a single drive, they just get written to simultaneously as far as I know (which isn't very far at all actually).

I'd be really interested if anybody can explain that point, as it would be helpful to know what I am dealing with, especially if there is an underlying problem other than the software.

Cheers

Billy 8-{)

Iantech
04-08-2011, 01:31 AM
I had a pair of mirrored 500Gb blues, one kept dropping out every few weeks and needed rebuilding, just a matter of unplugging it and plugging it back in and it would rebuild and be fine for another few weeks (doesnt necessarily mean it was the drive, may have been the driver before I know). Recently upgraded to a pair 1Tb blacks and havent had any problem at all, only thing I can say about them is that they are a bit noisier as they dont support AAM, on the up side, I appear to have faster disk access.

Many here dont recommend blacks, but I have never had an issue with them in any systems I have built so far.

If one or both of mine do crap out, they have a 5 year warranty so its not an issue as they will be replaced. And they will be upgraded in a few years time to something else anyway. Also run a 3rd non-raid 1Tb black in the system for extra storage, its never missed a beat also (yet).

My :2cents: worth.
Cheers

SolMiester
04-08-2011, 09:49 AM
From WD website


Western Digital manufactures desktop edition hard drives and RAID Edition (RE) hard drives. Each type of hard drive is designed to work specifically as a stand-alone drive, or in a multi-drive RAID environment.

If you install and use a desktop edition hard drive connected to a RAID controller, the drive may not work correctly. This is caused by the normal error recovery procedure that a desktop edition hard drive uses.
NOTE Note: There are a few cases where the manufacturer of the RAID controller have designed their cards to work with specific model Desktop drives. If this is the case you would need to contact the manufacturer of that controller for any support on that drive while it is used in a RAID environment. Desktop Class Hard Drives are tested and recommended for use in consumer-type RAID applications (RAID-0 / RAID-1). For more information about using a Desktop hard drive in a RAID please see Answer ID 996: Support for WD desktop drives in a RAID 0 or RAID 1 configuration.

When an error is found on a desktop edition hard drive, the drive will enter into a deep recovery cycle to attempt to repair the error, recover the data from the problematic area, and then reallocate a dedicated area to replace the problematic area. This process can take up to 2 minutes depending on the severity of the issue. Most RAID controllers allow a very short amount of time for a hard drive to recover from an error. If a hard drive takes too long to complete this process, the drive will be dropped from the RAID array. Most RAID controllers allow from 7 to 15 seconds for error recovery before dropping a hard drive from an array. Western Digital does not recommend installing desktop edition hard drives in an enterprise environment (on a RAID controller).

Western Digital RAID edition hard drives have a feature called TLER (Time Limited Error Recovery) which stops the hard drive from entering into a deep recovery cycle. The hard drive will only spend 7 seconds to attempt to recover. This means that the hard drive will not be dropped from a RAID array. While TLER is designed for RAID environments, a drive with TLER enabled will work with no performance decrease when used in non-RAID environments.
STOP Critical: WD Caviar Black, Caviar Green, and Caviar Blue hard drives are not recommended for and are not warranted for use in RAID environments utilizing Enterprise HBAs and/or expanders and in multi-bay chassis, as they are not designed for, nor tested in, these specific types of RAID applications. For all Business Critical RAID applications, please consider WD’s Enterprise Hard Drives that are specifically designed with RAID-specific, time-limited error recovery (TLER), are tested extensively in 24x7 RAID applications, and include features like enhanced RAFF technology and thermal extended burn-in testing.

SolMiester
04-08-2011, 09:53 AM
Answer ID 996 | Last Updated 06/08/2011
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WD desktop hard drives (Caviar Black, Green, and Blue) have been tested and are recommended for consumer RAID applications when using the drives in a RAID 0 (Stripe) or RAID 1 (Mirror) configuration.

However, there are several things to keep in mind when setting up a RAID with these drives:

WD only recommends using a Desktop drive in a RAID array with no more than two (2) drives (Raid 0 or Raid 1 only).
WD is unable to provide direct technical support for setting up RAID arrays for either hardware or software arrays.
Support for your RAID array can be obtained from one of several sources:
If you are setting up a hardware array it is best to contact the manufacturer of your RAID controller or motherboard manufacturer.
If you are setting up a software array you can contact the publisher of your RAID software.
The publisher of your Operating System (OS) (Usually Apple, or Microsoft) can provide support for the use of a hardware or software RAID configuration within that OS.
Before connecting a drive to an array, you should verify that the drive is functioning properly. Please use Data Lifeguard Diagnostic for DOS (floppy), Data Lifeguard Diagnostic for DOS (CD), or Windows Data Lifeguard Diagnostics to perform a test on the drive prior to installation.

1101
04-08-2011, 10:21 AM
how are the enterprise driver different from the black/green drives etc?

Designed?/intended for use in servers, so should have better reliability & better NCQ (?)

Billy T
04-08-2011, 10:37 PM
Well, the first of my new drives has arrived, it is a WD 750GB Caviar Black WD7502AAEX and on reading the specs and reviews (as much as I can understand of the techno-babble) it is a good performer and is considered suitable for Consumer level RAID 1 (and other RAID configurations as well). I'll drop it in on the weekend and see how it goes.

Although mine is technically a "business" application, it is far less demanding than many keen computer users would be (you can tell that from the fact that I see very little discernable speed difference between this new 2.6GHz CPU and 2GB of RAM vs my old PIII 550MHz with 512MB of ram) and I notice that the old comp boots in about the same time, but shuts down twice as quickly so go figure?

My usage is certainly far less demanding that that of even a casual gamer. I work mainly in text with nothing graphics intensive, plus Word, Publisher and Excel and a few other odd programs including DOS instrument software. In fact I've spent much of this week in a DOS program, sans mouse and keyboarding everything. Talk about going back to your roots!

Cheers

Billy 8-{)