ORNL-TechInt/lester

Lester, the Lustre lister

Lester is an extention of e2scan for generating lists of files (and potentially
their attributes) from a ext2/ext3/ext4/ldiskfs filesystem. We primarily use it
for generating a purge candidate list, but it is also useful for generating a
list of files affected by an OST outage or providing a name for an inode.

For example, to list files that have not been accessed in two weeks and
put the output in ne2scan format in $OUTFILE:

	touch -d 'now - 2 weeks' /tmp/flag
	lester -A fslist -a before=/tmp/flag -o $OUTFILE $BLOCKDEV

To do the same thing, but generate a full listing of the filesystem in
parallel:

	touch -d 'now - 2 weeks' /tmp/flag
	lester -A fslist -a before=/tmp/flag -a genhit=$UNACCESSED_LIST \
		-o $FULL_LIST $BLOCKDEV

To name inodes to stdout (when not using Lustre 2.4's LINKEA):

	lester -A namei -a $INODE1 -a $INODE2 ... $BLOCKDEV

To get a list of files with objects on OSTs 999 and 1000:

	lester -A lsost -a 999 -a 1000 -o $OUTFILE $BLOCKDEV

To get a list of options and actions, use 'lester -h'; to get a list of
options for a given action, use 'lester -A $ACTION -a help'.

Lester uses its own AIO-based IO engine by default, which is usually much
faster than the default Unix engine for large filesystems on high-performance
devices. The number of requests in flight, request size, cache size, and
read-ahead settings for various phases of the scan are all configurable. I
recommend experimenting with the settings to find a balance between speed and
resource usage for your situation.

-- David Dillow


DEPENDENCIES

libext2fs-devel		1.42.7 or newer (Lustre version preferred)
libcom_err-devel	1.42.7 or newer (Lustre version preferred)
libaio-devel

Older e2fsprogs libraries may work, but have not been tested

BUILDING

./bootstrap (if building from git repo)
./configure
make