Lustre 1.6 Operations Manual

To fix dangling inodes, lfsck creates new zero-length objects on the OSTs if the -c
option is given. These files read back with binary zeros for the stripes that had
objects recreated. Such files can also be read even without lfsck repair by using this
command, run:
$ dd if=/lustre/bad/file of=/new/file bs=4k conv=sync,noerror.
Because it is rarely useful to have files with large holes in them, most users delete
these files after reading them (if useful) and/or restoring them from backup.
Note – You cannot write to the holes of such files without having lfsck recreate the
objects. Generally, it is easier to delete these files and restore them from backup.
To fix inodes with duplicate objects, lfsck copies the duplicate object to a new
object, and assign that to one of the files if the -c option is given. One of the files
will be okay, and one will likely contain garbage; lfsck cannot, by itself, tell which
one is correct.
28-18 Lustre 1.6 Operations Manual • September 2008