Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 730 — #756
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backup superblock is dependent on the filesystem’s
blocksize. For filesystems with 1k blocksizes, a
backup superblock can be found at block 8193; for
filesystems with 2k blocksizes, at block 16384; and
for 4k blocksizes, at block 32768.
Additional backup superblocks can be determined by
using the mke2fs program using the -n option to
print out where the superblocks were created. The
-b option to mke2fs, which specifies blocksize of
the filesystem must be specified in order for the
superblock locations that are printed out to be
accurate.
If an alternative superblock is specified and the
filesystem is not opened read-only, e2fsck will
make sure that the primary superblock is updated
appropriately upon completion of the filesystem
check.
-B blocksize
Normally, e2fsck will search for the superblock at
various different block sizes in an attempt to find
the appropriate block size. This search can be
fooled in some cases. This option forces e2fsck to
only try locating the superblock at a particular
blocksize. If the superblock is not found, e2fsck
will terminate with a fatal error.
-c This option causes e2fsck to run the badblocks(8)
program to find any blocks which are bad on the
filesystem, and then marks them as bad by adding
them to the bad block inode. If this option is
specified twice, then the bad block scan will be
done using a non-destructive read-write test.
-C fd This option causes e2fsck to write completion
information to the specified file descriptor so
that the progress of the filesystem check can be
monitored. This option is typically used by pro
grams which are running e2fsck. If the file
descriptor specified is 0, e2fsck will print a com
pletion bar as it goes about its business. This
requires that e2fsck is running on a video console
or terminal.
-d Print debugging output (useless unless you are
debugging e2fsck).
-D Optimize directories in filesystem. This option
causes e2fsck to try to optimize all directories,
either by reindexing them if the filesystem sup
ports directory indexing, or by sorting and com
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