Re: Fwd: How to read bad blocks error message marking of same
Mike Meyer wrote: Modern drives deal with bad block substitution all by themselves. Umm - not quite, right? That is, if a block goes bad and you get a read error, the drive isn't going to do any substituting at that point. You'll just continue to get the read error if you try to access (read) that block. It's only when you allow another *write* to that block (e.g. by deleting the original file and writing new files) that the drive will automatically substitute a spare block for the one that went bad. By the time you've got blocks going bad that the OS sees, the drive is in really sad shape. You should replace it with a new drive ASAP. If, after you have (for certain!) overwritten the bad block(s) and you still get errors, then yes the drive is on its way out. But simply getting a read error (without any overwrite attempt) from a block or two doesn't necessarily mean that the drive is turning to mush, now does it? Gary ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Fwd: How to read bad blocks error message marking of same
In the last episode (Aug 06), Gary Corcoran said: Mike Meyer wrote: Modern drives deal with bad block substitution all by themselves. Umm - not quite, right? That is, if a block goes bad and you get a read error, the drive isn't going to do any substituting at that point. You'll just continue to get the read error if you try to access (read) that block. It's only when you allow another *write* to that block (e.g. by deleting the original file and writing new files) that the drive will automatically substitute a spare block for the one that went bad. SCSI drives, at least, may do automatic reallocation on both reads and writes ( camcontrol mode da0 -m 1, the ARRE and AWRE flags ). If the drive had to reread the block or had to use ECC to recover data, AND the entire block was recovered, it will relocate the data if ARRE is set. -- Dan Nelson [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Fwd: How to read bad blocks error message marking of same
Dan Nelson wrote: In the last episode (Aug 06), Gary Corcoran said: Mike Meyer wrote: Modern drives deal with bad block substitution all by themselves. Umm - not quite, right? That is, if a block goes bad and you get a read error, the drive isn't going to do any substituting at that point. You'll just continue to get the read error if you try to access (read) that block. It's only when you allow another *write* to that block (e.g. by deleting the original file and writing new files) that the drive will automatically substitute a spare block for the one that went bad. SCSI drives, at least, may do automatic reallocation on both reads and writes ( camcontrol mode da0 -m 1, the ARRE and AWRE flags ). If the drive had to reread the block or had to use ECC to recover data, AND the entire block was recovered, it will relocate the data if ARRE is set. Good to know, although I stopped buying SCSI disks (for home use) years ago. I presumed the more common case these days, that we were talking about IDE disks. In fact doesn't this (from the original question): ad0s1a: hard error necessarily refer to an ATA (IDE) disk? I don't believe any (current) ATA disks will do automatic reallocation on reads, will they? Though of course serial ATA drives seem to be the future and are taking on more and more SCSI-like features as time goes by. Gary ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Fwd: How to read bad blocks error message marking of same
On Fri, Aug 06, 2004, Gary Corcoran wrote: Dan Nelson wrote: In the last episode (Aug 06), Gary Corcoran said: Mike Meyer wrote: Modern drives deal with bad block substitution all by themselves. Umm - not quite, right? That is, if a block goes bad and you get a read error, the drive isn't going to do any substituting at that point. You'll just continue to get the read error if you try to access (read) that block. It's only when you allow another *write* to that block (e.g. by deleting the original file and writing new files) that the drive will automatically substitute a spare block for the one that went bad. SCSI drives, at least, may do automatic reallocation on both reads and writes ( camcontrol mode da0 -m 1, the ARRE and AWRE flags ). If the drive had to reread the block or had to use ECC to recover data, AND the entire block was recovered, it will relocate the data if ARRE is set. Good to know, although I stopped buying SCSI disks (for home use) years ago. I presumed the more common case these days, that we were talking about IDE disks. In fact doesn't this (from the original question): ad0s1a: hard error necessarily refer to an ATA (IDE) disk? I don't believe any (current) ATA disks will do automatic reallocation on reads, will they? Though of course serial ATA drives seem to be the future and are taking on more and more SCSI-like features as time goes by. Both ATA and SCSI drives may relocate blocks that were difficult to read (e.g. correctable errors, took multiple attempts, etc). But if the block can't be recovered at all, the drive will still report an error to the OS (in addition to relocation). ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Fwd: How to read bad blocks error message marking of same
it was said: Modern drives deal with bad block substitution all by themselves. Umm - not quite, right? That is, if a block goes bad and you get a read error, the drive isn't going to do any substituting at that point. You'll just continue to get the read error if you try to access (read) that block. It's only when you allow another *write* to that block (e.g. by deleting the original file and writing new files) that the drive will automatically substitute a spare block for the one that went bad. SCSI drives, at least, may do automatic reallocation on both reads and writes ( camcontrol mode da0 -m 1, the ARRE and AWRE flags ). If the drive had to reread the block or had to use ECC to recover data, AND the entire block was recovered, it will relocate the data if ARRE is set. Good to know, although I stopped buying SCSI disks (for home use) years ago. I presumed the more common case these days, that we were talking about IDE disks. In fact doesn't this (from the original question): ad0s1a: hard error necessarily refer to an ATA (IDE) disk? I don't believe any (current) ATA disks will do automatic reallocation on reads, will they? Though of course serial ATA drives seem to be the future and are taking on more and more SCSI-like features as time goes by. Both ATA and SCSI drives may relocate blocks that were difficult to read (e.g. correctable errors, took multiple attempts, etc). But if the block can't be recovered at all, the drive will still report an error to the OS (in addition to relocation). Hello, A tool that all may find useful is SpinRite 6.0 available from Gibson Research at http://www.grc.com/sr/spinrite.htm. It's not open source or freeware but anybody with an Intel, AMD, or TiVO system that uses a harddrive ought to have it. Note: I am in no way affiliated with Gibson Research, other than having used SpinRite since the days of manually interleaving MFM drives. HTH, Stheg __ Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages! http://promotions.yahoo.com/new_mail ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Fwd: How to read bad blocks error message marking of same
In [EMAIL PROTECTED], DH [EMAIL PROTECTED] typed: I'm reposting this because I've not rec'd a response from the freebsd-fs mailing list yet and I need an answer fairly quickly. Thanks be any who can help out! The correct place to send this is freebsd-questions. I've added that to the list, and pointed replies there as well. I've begun rec'ing these error messages: ad0s1a: hard error reading fsbn 141935 of 70848 - 71103 (ad0s1 bn 141935; cn 8 tn 212 sn 59 ) status=59 error=40 Got about 7 of these with varying values. I ran Seagate's diag utility and it reported only 1 bad sector (# 71099 ). Unfortunately ad0s1a happens to my / dir so allowing the utility to write zeros to that block hasn't sat well with me. Sooo - if some one could explain the exact meaning of my error message point me in the right direction to use these values to fix my disk problem I'd greatly appreciate it (with many many many thanks in advance :) ) Modern drives deal with bad block substitution all by themselves. By the time you've got blocks going bad that the OS sees, the drive is in really sad shape. You should replace it with a new drive ASAP. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
