On Nov 01, 2005 12:45 +1100, Vincent.McIntyre@xxxxxxxx wrote: > >It sounds like you have overflowed the end of the 2TB device limit and > >clobbered the beginning of your filesystem. This can happen if the > >SCSI driver, kernel, or even ext3 isn't handling offsets > 2^31 properly. > >I know RH has only recently started supporting ext3 filesystems > 2TB, > >and it isn't clear that all drivers handle this properly yet. > > This box is using the fusion mpt drivers as in 2.6.7 - mptbase,mptscsih > etc. Do you recall any >2Tb issue being fixed in later kernels? Sorry, I don't know, I've just heard of occasional problems in this area and very few people reporting success. > When the machine was last in a good state, the filesystem had 1.5Tbyte > used, ie as far as I can tell nothing would have written past 2Tb, > although I suppose there is no guarantee the space is used up in order > of increasing offset. No, it is "kind of" used in increasing offset, but not strictly so. > >Please update your e2fsprogs to the latest. You also need to use > >"e2fsck -b 32768" (or multiple thereof) for such large filesystems. > >I think newer e2fsprogs will print this message properly in that case. You might also need to add "-B 4096". > I downloaded 1.38 from sourceforge and built it. No change in behaviour. > I tried e2fsck with block offsets from 1025 to 4194305 in steps of 1024. > I also tried dumpe2fs with the same range of offsets, also nothing. > > > Another question. The e2fsck(8) manpage says the superblocks are at - > Blocksize -b > 1k 8193 > 2k 16384 > 4k 32768 > Why is the superblock offset for 1k at 8193, not 8192? Because the ext[23] superblock is at 1024 bytes offset from the beginning of the device. For 1kB blocksize this is a whole block so the filesystem starts at block 1, while for larger blocksize this is still in block 0. Backup superblocks are at block offsets: (blocksize * 8) * {3,5,7}^n, n={0,1,2,3...} Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. _______________________________________________ Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users