Hi! > > > > What are ext3 expectations of disk (is there doc somewhere)? For > > > > example... if disk does not lie, but powerfail during write damages > > > > the sector -- is ext3 still going to work properly? > > > > > > Nope. However the few disks that did this rapidly got firmware updates > > > because there are other OS's that can't cope. > > > > > > > If disk does not lie, but powerfail during write may cause random > > > > numbers to be returned on read -- can fsck handle that? > > > > > > most of the time. and fsck knows about writing sectors to remove read > > > errors in metadata blocks. > > > > > > > What abou disk that kills 5 sectors around sector being written during > > > > powerfail; can ext3 survive that? > > > > > > generally. Note btw that for added fun there is nothing that guarantees > > > the blocks around a block on the media are sequentially numbered. The > > > usually are but you never know. > > > > Ok, should something like this be added to the documentation? > > > > It would be cool to be able to include few examples (modern SATA disks > > support bariers so are safe, any IDE from 1989 is unsafe), but I do > > not know enough about hw... > > ext3 is not the only filesystem that will have trouble due to > volatile write caches. We see problems often enough with XFS > due to volatile write caches that it's in our FAQ: > > http://oss.sgi.com/projects/xfs/faq.html#wcache Nice FAQ, yep. Perhaps you should move parts of it to Documentation/ , and I could then make ext3 FAQ point to it? I had write cache enabled on my main computer. Oops. I guess that means we do need better documentation. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
