Hi! On 15:15 Mon 22 Dec , pradeep singh wrote: > On Mon, Dec 22, 2008 at 3:10 PM, Sandeep K Sinha > <sandeepksinha@xxxxxxxxx> wrote: > > Hi pradeep, > > > > On Mon, Dec 22, 2008 at 2:54 PM, pradeep singh > > <pradeep.rautela@xxxxxxxxx> wrote: > >> On Sun, Dec 21, 2008 at 7:52 PM, Sandeep K Sinha > >> <sandeepksinha@xxxxxxxxx> wrote: > >> [snip] > >>>> > >>> > >>> When you say a file system as consistent, It means that you would be > >>> able to mount the filesystem. The superblock would be in the > >>> consistent state. > >>> The point is that even if you loose the data for a couple of files, > >>> still your file system will be up and you would be able to access the > >>> data for other files. > >>> If you loose the consistency of a file system( e.g superblock) then > >>> would loose everything. > >>> > >>> There are other tools that can be used to recover the data of a file > >>> or revert back the file to a consistent state but if you loose > >>> superblock then you land NOWHERE. > >> > >> Perfectly right but that may be a one off scenario. Usually modern > >> filesystems would keep multiple copies of superblock, so even if your > >> superblock is damaged you can still recover the fs to a sane state by > >> forcing fsck to use an alternative superblock. > >> > >> Hope this helps somehow. > >> > > > > No offense, but remember that fsck fails too. > > There are instances where this is possible. > > Can you please describe any scenario, where this may happen? There are lots of ways a filesystem can be damaged which do not involve the superblocks. I have found some information which are done by fsck at http://e2fsprogs.sourceforge.net/ext2intro.html I do not trust fsck that much. I have had a damaged file system which was *destroyed* by e2fsck - mountable with IO errors before, not mountable afterwards. In another case I did a repair and e2fsck said the file system was ok. A few weeks later there were errors again... Ok, that was not rock science, just my experience. > One i can think of is when your /sbin is groked. > > I wonder if this is the case, then what happens when fsck itself > cannot be invoked. though your superblock is intact you still cannot > have a sane state for your fs because effectively fsck is not there. > How do we handle such situations? > Any hints? Boot with a cd which contains fsck? -Michi -- programing a layer 3+4 network protocol for mesh networks see http://michaelblizek.twilightparadox.com -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
