Problem with running the relocation is that the RAID-5 will now be corrupt. The RAID-5 algorithm needs to be in-touch with disk block relocation so that it can correct the parity and the data. Sincerely -- Mark Salyzyn -----Original Message----- From: dean gaudet [mailto:dean-list-linux-raid@xxxxxxxxxx] Sent: Friday, August 06, 2004 5:59 PM To: Kanoa Withington Cc: Salyzyn, Mark; Derek Listmail Acct; linux-raid@xxxxxxxxxxxxxxx Subject: RE: Scrub? On Fri, 6 Aug 2004, Kanoa Withington wrote: > On Fri, 6 Aug 2004, Salyzyn, Mark wrote: > > Just reading the entire array should correct the bad blocks, so reverse > > the sense of the dd: > > > > dd if=/dev/md0 of=/dev/null bs=200b > > > > to find and replace the bad blocks (making the assumption that md works > > like the H/W RAID cards). > > In this case software RAID does not work like the H/W cards. Finding > an unreadable block that way in a software array would cause it to go > into a degraded state. if the disks support SMART (i.e. they're less than a few years old) then try running the smart long selftest... it can be done online and on many disks it will force sector reallocation (and produce a SMART log event so you know it happenned). get smartmontools and run "smartctl -a" to see info on your drive, and "smartctl -t long" to launch the long test. man page has more examples. i run smart long tests on each my disks once a week (staggerred over many nights)... see /etc/smartd.conf. -dean - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
