Yeah, I opened a case with Dell support before sending this message. Haven't been blown away. The technician is Googling the error--not exactly the kind of expertise I was expecting.
-----Original Message----- From: Ben Scott [mailto:[email protected]] Sent: Tuesday, May 04, 2010 11:16 AM To: NT System Admin Issues Subject: Re: Problem with RAID 5 Array On Tue, May 4, 2010 at 10:26 AM, John Hornbuckle <[email protected]> wrote: > So, what gives? The array reports everything is fine. But obviously, > something is funky. I can restore the four corrupt files from a > backup-that's no problem. But not if I can't first delete the bad versions. I'd call Dell tech support. It's free and sometimes even helpful. Not knowing more, my guess would be that one of the other disks has some bad blocks. Scenario: Most filesystems have a lot of files which are never or rarely read. Plus RAID 5 provides redundancy -- the controller may normally read the "primary" set of on-disk blocks and ignore the redundant blocks. End result, you've got blocks allocated on disk, but which are never read. Then a disk fails. Now the controller has to read *every* block of *all* the other disks, in order to rebuild the failed member. Boom. That's when you discoverer that one of the other disks has had bad blocks for years. Unfortunately, the only way to recovery from this scenario is to restore from good backups. For this reason, good controllers have a "patrol read" feature (or "background scrub", etc.), where they regularly read all blocks from all disks, to discover bad blocks as soon as they happen. -- 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/> ~
