Hi, Chkdsk doesn't know anything about the underlying disk subsystem - that's all managed by the storage miniport driver from the RAID controller vendor and the actual hardware RAID controller. If chkdsk says "this part is bad, don't use it" then it's up to the RAID controller vendor to implement the necessary functionality to move the data and/recalculate parity. The individual disks attached to the controller (I suspect) are the ones that keep track of which sectors are useable and make that information available to the RAID controller.
Cheers Ken From: Andrew Levicki [mailto:[email protected]] Sent: Saturday, 8 May 2010 11:12 AM To: NT System Admin Issues Subject: Re: Chkdsk on RAID 5 Hi John, Do you have any feedback for us on how this went, please? I've been puzzling over the issue of running chkdsk on RAID arrays and have done a little research but I cannot find anything from Microsoft about it and opinion is divided. My concern is this: how can the chkdsk software repair a physical disk subsystem? For example, I have a RAID-5 array and one of the disks in that array has a bad sector, how does chkdsk mark that bad sector without affecting the parity information across the rest of the array? Or lets say I have a RAID-1 mirror and one of the disks has a bad sector. Does it also mark a sector on my good disk as being bad? I would think if you are running hardware RAID, the hardware vendor would include a diagnostic utility which would be better to run than chkdsk. (e.g. hp Array diagnostics utility). Sorry to reopen the case, but I'm not so sure that it was so wise to let it rip... Kind regards, andrew On 6 May 2010 00:56, John Hornbuckle <[email protected]<mailto:[email protected]>> wrote: Yeah, we have reliable backups--so we're prepared for the worst. I'm going to run it tonight after my users have gone home and I can dismount the volume without disruption. I'm hoping that chkdsk fixes the problem (four files are inaccessible), or at least has no effect. But I'm prepared for the possibility that it will make things worse. John -----Original Message----- From: Ben Scott [mailto:[email protected]<mailto:[email protected]>] Sent: Wednesday, May 05, 2010 11:08 AM To: NT System Admin Issues Subject: Re: Chkdsk on RAID 5 On Wed, May 5, 2010 at 8:41 AM, John Hornbuckle <[email protected]<mailto:[email protected]>> wrote: > Is it safe to run chkdsk /f on a RAID 5 array? It's no more or less safe than running it on a single disk. (Which is to say: The filesystem is already damaged. You've probabbly already lost data. CHKDSK will almost certainly fix the errors on the filesystem. It's theoretically possible for CHKDSK to make things worse, although in practice that is exceedingly rare. Backups are always a good idea. This product is sold by weight, not be volume. Void where prohibited. Be kind to animals. Brush after every meal.) -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ NOTICE: Florida has a broad public records law. Most written communications to or from this entity are public records that will be disclosed to the public and the media upon request. E-mail communications may be subject to public disclosure. ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ -- Kind regards, Andrew Levicki MCITP:EDST7/EMA/EA,MCSE,MCSA,MCP,CCNA,ITIL ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
