Running CHKDSK on Software RAID 0

May 31, 2005
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I have 2 HDDs in a RAID 0 software array using nf4's nvraid (2 x 300 MAXTOR SATA). Recently my computer froze and I rebooted it to find out that windows lagged out on the boot screen until chkdsk came up.

Chkdsk froze on phase 1, 4% in (stayed on 4% for 2 hours). I have been searching around the internet and found some articles to suggest that CHKDSK'ng a RAID array may screw it up because of how striping works.

Here is a case of a RAID 5 hardware array and CHKDSK:
http://ask.metafilter.com/65106/Did-chkdsk-eat-my-files

This place says dont do it:
http://www.quetek.com/RAID_mistakes.htm

Chkdsk being run on one of the disks
Chkdsk is a Windows utility that uses simple algorithms to recover data from a corrupt disk. Chkdsk can be started by the user or automatically by Windows if it detects disk corruption at boot time. (Windows will ask for confirmation before starting chkdsk but will start it anyway if no response is received after a number of seconds.) Chkdsk is not RAID-aware. Its algorithms only work in the simplest cases. In general, it must be avoided.

If chkdsk attempts to repair one or more member disks, the RAID data patterns will be destroyed, usually beyond recovery.


I have booted it up to Windows Recovery Console and gotten access to the files, and everything appears to be good. Im using the nvraid drivers in the Windows Recovery Console to read the drive. Should I go ahead and run a chkdsk? Or should I do a reinstall of XP?

I understand that RAID 0 is a risky setup, and I understand I could lose all my files. I just really like this install of windows and the files are worth enough to me to try to fix this problem.


Any help or input would be appreciated!
 
May 31, 2005
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Originally posted by: Rubycon
I run a CHKDSK on mine all the time with 10 15K disks in RAID0.

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ROFL. Love the music.

It seems possible that if I ran chkdsk on a RAID and found a bad "sector" and it tried to repair it that it could be messing with striped data. Like shuffling cards.

Ill try running chkdsk though.
 

Nothinman

Elite Member
Sep 14, 2001
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I have been searching around the internet and found some articles to suggest that CHKDSK'ng a RAID array may screw it up because of how striping works.

If that happens then your array isn't working properly anyway.

Chkdsk is not RAID-aware. Its algorithms only work in the simplest cases. In general, it must be avoided.

If chkdsk attempts to repair one or more member disks, the RAID data patterns will be destroyed, usually beyond recovery.

That is retarded. Sure, chkdsk isn't the smartest tool in the shed but it doesn't need to understand RAID. The RAID portion is taken care of by the driver and controller doing the RAID, the NTFS filesystem on the array looks the same to chkdsk no matter what the underlying storage looks like.
 

RebateMonger

Elite Member
Dec 24, 2005
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That second quoted article is saying to not run Chkdsk ON AN INDIVIDUAL DRIVE. That WILL mess things up good. You run Chckdsk on the entire array.

On the other hand, Chkdsk CAN eat files and directories. It does whatever is necessary to "fix" the logical structure of the array. I've seen a case where a power glitch apparently damaged a drive plus the RAID 5 error correction system, and Chkdsk made many files and directories disappear. This was on an expensive EMC array.
 
May 31, 2005
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When I try running just normal chkdsk it just stays at 1% forever (I left it on overnight). Thats just regular chkdsk in windows recovery console with the RAID drivers loaded. I did not hear much hard drive activity either.

The RAID is detected as being healthy. Should I run the maxtor diagnostics for the drive, or would that mess up the raid stripes? Or just reinstall windows and try to backup all the files I can?
 

Nothinman

Elite Member
Sep 14, 2001
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That second quoted article is saying to not run Chkdsk ON AN INDIVIDUAL DRIVE. That WILL mess things up good. You run Chckdsk on the entire array.

That would be pretty stupid if you could even get it to work. The MFT would be striped too so chances are the drives would show up as RAW and chkdsk would refuse to run.

The RAID is detected as being healthy. Should I run the maxtor diagnostics for the drive, or would that mess up the raid stripes? Or just reinstall windows and try to backup all the files I can?

Most manfacturer diag tools just run SMART tests which are non-destructive.