From mboxrd@z Thu Jan 1 00:00:00 1970 From: eazgwmir@umail.furryterror.org (Zygo Blaxell) Subject: Re: Corrupted/unreadable journal: reiser vs. ext3 Date: 13 Feb 2003 15:08:49 -0500 Message-ID: References: <93F527C91A6ED411AFE10050040665D0049C06D5@corpusmx1.us.dg.com> <93F527C91A6ED411AFE10050040665D0049C06D5@corpusmx1.us.dg.com> <200302130522.35829.sam@vilain.net> Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: reiserfs-list@namesys.com In article <200302130522.35829.sam@vilain.net>, Sam Vilain wrote: >But with disks, you can. Mirroring aside, modern hard disks use S.M.A.R.>T. >technology which claims to be able to spot failures before they happen. >Many BIOSes will let you turn this feature on and off. Of course I've >never actually seen it in action :-). I have seen SMART work. At 11:20:30 I had a disk fail, then smartd put this in my logs: Nov 6 11:20:30 chlorine smartd: Device: /dev/hdb, Failed attribute: 3 Oh, wait, you said "before"...no, I've never actually seen that in action either. SMART does give you statistics on ECC recovery rates, temperature, number of remapped sectors, etc. which can give you a hint, if you keep track of them over time, when your disk is beginning to have more problems than it did have when it was newer. Maybe about 50% of failures can be predicted this way (but you have no idea _when_ the failure will occur--this afternoon or next summer?) it's little better than the MTBF rating. The other 50% of failures are predicted only after the fact. :-P -- Zygo Blaxell (Laptop) GPG = D13D 6651 F446 9787 600B AD1E CCF3 6F93 2823 44AD