We have two RAID cards of different heritage over here with differing definitions. One defines scrub as a means of erasing any content and ensuring all blocks have correct parity or redundancy information; the other defines it solely for RAID-5 to rebuild all the parity blocks. The action in the second case resolves itself as a result of reading the bad block. 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). Sincerely -- Mark Salyzyn -----Original Message----- From: Kanoa Withington [mailto:kanoa@xxxxxxxxxxxxxxx] Sent: Friday, August 06, 2004 3:03 PM To: Salyzyn, Mark Cc: Derek Listmail Acct; linux-raid@xxxxxxxxxxxxxxx Subject: RE: Scrub? Eh, that would delete the contents of the array, including the filesystem. Is that what you meant by "scrub"? I thought "scrubbing" meant looking for unreadable blocks and pro-actively replacing them from parity. The latter would be very useful for a software raid 5 array since there is currently no facility in software raid for doing this on-the-fly. I imagine it would be possible to write such a utility in user space. I, too, wonder if anyone out there has something that works. -Kanoa On Fri, 6 Aug 2004, Salyzyn, Mark wrote: > dd if=/dev/zero of=/dev/md0 bs=200b > > -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx > [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Derek Listmail > Acct > Sent: Friday, August 06, 2004 2:07 PM > To: linux-raid@xxxxxxxxxxxxxxx > Subject: Scrub? > > Many of the hardware raid controllers I've used have the ability to run > a > 'scrub' on an array. Is there a way to do this on a linux software raid > 5 > array? > > > - > 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 > - > 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 > - 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
