* bad bread
@ 2006-05-05 10:28 boricua
2006-05-07 0:56 ` rvalles
[not found] ` <20060507005618.GA21557@rvalles.homedns.org.>
0 siblings, 2 replies; 7+ messages in thread
From: boricua @ 2006-05-05 10:28 UTC (permalink / raw)
To: reiserfs-list
running reiserfsck -B bbfile /dev/hda4 is giving me following error
"bread: cannot read the block 16 [i/o error]
anyway aroound this?
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: bad bread 2006-05-05 10:28 bad bread boricua @ 2006-05-07 0:56 ` rvalles [not found] ` <20060507005618.GA21557@rvalles.homedns.org.> 1 sibling, 0 replies; 7+ messages in thread From: rvalles @ 2006-05-07 0:56 UTC (permalink / raw) To: reiserfs-list; +Cc: boricua On Fri, May 05, 2006 at 06:28:01AM -0400, boricua wrote: > running reiserfsck -B bbfile /dev/hda4 is giving me following error > > "bread: cannot read the block 16 [i/o error] > > anyway aroound this? > IO error means block-layer level failure, that is, physical failure. In the event of physical HD failure, the procedure goes like this: - get a bigger partition somewhere reachable (new hard disk, nfs, whatever) - boot knoppix, use dd_rescue to dump as much as possible of faulty disk into a file on the bigger partition. Pad not recoverable zones with zeroes so that the pointers arent screwed up. - run fsck on the image you created - mount and recover. Good luck. -- - Do you study theories? - Oh yes! Theories are fun. - How do you use them? - When I must act, theories are too slow. To act, I must know. ^ permalink raw reply [flat|nested] 7+ messages in thread
[parent not found: <20060507005618.GA21557@rvalles.homedns.org.>]
* Re: bad bread [not found] ` <20060507005618.GA21557@rvalles.homedns.org.> @ 2006-05-07 8:35 ` PFC 2006-05-08 19:47 ` Valdis.Kletnieks 0 siblings, 1 reply; 7+ messages in thread From: PFC @ 2006-05-07 8:35 UTC (permalink / raw) To: rvalles, reiserfs-list; +Cc: boricua > In the event of physical HD failure, the procedure goes like this: Get mail saying a HDD is dead. Replace harddisk, resynchronize RAID. Use Linux software RAID. Harddrives are cheaper that the time you'll lose trying to recover your data. I have reiserfs on RAID1 on my PC ; the kernel can distribute random reads to both disks, so it is faster and more responsive. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: bad bread 2006-05-07 8:35 ` PFC @ 2006-05-08 19:47 ` Valdis.Kletnieks 2006-05-08 20:32 ` Sander 2006-05-08 22:18 ` PFC 0 siblings, 2 replies; 7+ messages in thread From: Valdis.Kletnieks @ 2006-05-08 19:47 UTC (permalink / raw) To: PFC; +Cc: rvalles, reiserfs-list, boricua [-- Attachment #1: Type: text/plain, Size: 774 bytes --] On Sun, 07 May 2006 10:35:44 +0200, PFC said: > > > In the event of physical HD failure, the procedure goes like this: > > Get mail saying a HDD is dead. Replace harddisk, resynchronize RAID. > Use Linux software RAID. Harddrives are cheaper that the time you'll lose > trying to recover your data. Remember to take backups *anyhow*. That way, if the RAID controller dumps cow manure on all the sectors, you won't be saying "Oh, SH*T". Also, note that there exist buggy RAID controllers, where if you are doing mirroring to 2 disks, and they develop bad blocks at different locations, you can trash the mirror by resynchronizing (basically, you swap out one of the bad disks, re-sync, it progresses as far as the bad block on the source for the mirror, and dies). [-- Attachment #2: Type: application/pgp-signature, Size: 226 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: bad bread 2006-05-08 19:47 ` Valdis.Kletnieks @ 2006-05-08 20:32 ` Sander 2006-05-08 22:18 ` PFC 1 sibling, 0 replies; 7+ messages in thread From: Sander @ 2006-05-08 20:32 UTC (permalink / raw) To: Valdis.Kletnieks; +Cc: PFC, rvalles, reiserfs-list, boricua Valdis.Kletnieks@vt.edu wrote (ao): > On Sun, 07 May 2006 10:35:44 +0200, PFC said: > > > In the event of physical HD failure, the procedure goes like this: > > > > Get mail saying a HDD is dead. Replace harddisk, resynchronize RAID. > > Use Linux software RAID. Harddrives are cheaper that the time you'll lose > > trying to recover your data. > > Remember to take backups *anyhow*. That way, if the RAID controller dumps > cow manure on all the sectors, you won't be saying "Oh, SH*T". Or user error (rm -rf, fdisk, dd, mkswap) or bad memory or fire or broken new kernel or script kiddies or worms/viruses or .. With kind regards, Sander -- Humilis IT Services and Solutions http://www.humilis.net ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: bad bread 2006-05-08 19:47 ` Valdis.Kletnieks 2006-05-08 20:32 ` Sander @ 2006-05-08 22:18 ` PFC 2006-05-09 18:46 ` Valdis.Kletnieks 1 sibling, 1 reply; 7+ messages in thread From: PFC @ 2006-05-08 22:18 UTC (permalink / raw) To: Valdis.Kletnieks; +Cc: rvalles, reiserfs-list, boricua > Remember to take backups *anyhow*. That way, if the RAID controller > dumps cow manure on all the sectors, you won't be saying "Oh, SH*T". Linux software RAID doesn't need a controller ;) But yes, backups should be done anyways. IMHO, RAID is good, harddisks are less reliable than the linux kernel, the linux RAID layer, and reiserfs. > Also, note that there exist buggy RAID controllers, where if you are > doing > mirroring to 2 disks, and they develop bad blocks at different locations, > you can trash the mirror by resynchronizing (basically, you swap out one > of > the bad disks, re-sync, it progresses as far as the bad block on the > source > for the mirror, and dies). Linux RAID has a special option for that : you can trigger a check, which will re-read the entire disks and, if a read error occurs, re-write the failing sector with good data from the other drives in the RAID. The drive with the bad sector will then remap it to another sector. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: bad bread 2006-05-08 22:18 ` PFC @ 2006-05-09 18:46 ` Valdis.Kletnieks 0 siblings, 0 replies; 7+ messages in thread From: Valdis.Kletnieks @ 2006-05-09 18:46 UTC (permalink / raw) To: PFC; +Cc: rvalles, reiserfs-list, boricua [-- Attachment #1: Type: text/plain, Size: 615 bytes --] On Tue, 09 May 2006 00:18:32 +0200, PFC said: > Linux RAID has a special option for that : you can trigger a check, which > will re-read the entire disks and, if a read error occurs, re-write the > failing sector with good data from the other drives in the RAID. The drive > with the bad sector will then remap it to another sector. If you have 2 mirrored disks, and are replacing one, you don't have a good block to read it from. The failure mode was a RAID controller that didn't properly handle re-writing the bad block on the first disk, so when the second disk got a bad block, you were screwed.... [-- Attachment #2: Type: application/pgp-signature, Size: 226 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2006-05-09 18:46 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2006-05-05 10:28 bad bread boricua
2006-05-07 0:56 ` rvalles
[not found] ` <20060507005618.GA21557@rvalles.homedns.org.>
2006-05-07 8:35 ` PFC
2006-05-08 19:47 ` Valdis.Kletnieks
2006-05-08 20:32 ` Sander
2006-05-08 22:18 ` PFC
2006-05-09 18:46 ` Valdis.Kletnieks
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