From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: Corrupted/unreadable journal: reiser vs. ext3 Date: Tue, 11 Feb 2003 23:27:50 +0300 Message-ID: <3E495CC6.8020202@namesys.com> References: <3E494808.413781E@interface-ag.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <3E494808.413781E@interface-ag.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Dirk Schenkewitz Cc: Reiserfs List , Vitaly Fertman I have to tell you that if you aren't willing to run fsck for reiserfs in response to disk corruption, but you are willing to switch to a filesystem (ext2) that runs fsck at every boot, I don't have a lot of sympathy. Vitaly can comment more. Hans Dirk Schenkewitz wrote: >Hi Guys, > >Recently I read about ReiserFS V4, taking that as a reason to take >a look at ReiserFS again. But I'm not sure if it's worth to switch >from ext3/ext2 to reiser. Because: > >More than a year ago, I made up one reiser-partition for playing >around. Well, first there seemed to be nothing special about it. >Then, one day, it suddenly couldn't read its journal anymore, >which prevented the system from booting. (about 2 weeks later I >discovered why: a bad power supply had caused physical damage to >that area of the hard disk) For some reason I don't recall anymore, >I couldn't find a reiserfsck or such. I found no way to get around >the case of a corrupted/unreadable journal. > >Luckily, the partition was nearly empty, so I put on an ext3 system >on that partition. That went fine for just a few days, than the bad >disk area (which now held the ext3-journal) decided to strike again. >But guess what happened: >While booting the next time, the ext3 code discovered that the jour- >nal was unreadable (watching that, I thought "oh shit, not again" - >for less than a second), put out a short message stating that and >that it will continue as ext2. No painfull attempts to recover the >journal - it just dropped it and continued, taking only a few seconds >for that. >No data was lost! I sat there for some time, staring at the screen, >hardly believing it. > >After that, I removed reiser-support from the kernels I used and >since then I only used ext3. If I lost some data since then, it was >only because I accidentally deleted it - there seems to be no way >to recover anything from ext3 (unlike ext2). > >Because I have large amounts of data, reliability and solidness of >a filesystem are the most important things to me, then comes space- >efficiency, then speed. Sometimes some of my filesystems get 100% >full, having only some kilobytes left (of, say, 8Gig) until I clean >up. That's my personal situation & experiences. > >Now my questions: >>>From reading the mails from this list, I suspect that a ReiserFS: > - will sport poor performance (whatever that means, in terms of > absolute speed) if it gets more than 96% full. (*1*) > - will fall far behind ext3 when it comes to reliability, robust- > ness and crash recovery (at least when fsck is involved), > - and will have even more trouble (which may lead to complete fai- > lure) if the journal cannot be accessed. >Is any of this still true? > >(*1*): What if the filesystem contains rather large files, like > CD-images, MP3s and such, filling it up completely ? Will > it still slow down? > >>>From what I wrote, you may think that I have some prejudice against >ReiserFS. That's true, I have, because I had a bad experience with >it. Anyway, if you (the developers and/or other people reading here) >can say that nowadays ReiserFS is better than ext3, even under my >personal harsh circumstances, I will give it another try. And now, >feel free to flame me. :-) > >happy coding > dirk > > -- Hans