- HAMMER
Infobox filesystem
name = HAMMER
developer = Matthew Dillon
full_name = HAMMER
introduction_date =July 21 ,2008
introduction_os =DragonFly BSD 2.0
partition_id =
directory_struct =B-tree
file_struct =
bad_blocks_struct =
max_file_size =
max_files_no =
max_filename_size =
max_volume_size = 1EiB
dates_recorded =
date_range =
date_resolution =
forks_streams =
attributes =
file_system_permissions =
compression =
encryption =
OS =DragonFly BSD HAMMER is a high-availability
64-bit clusteringfile system developed by Matthew Dillon forDragonFly BSD usingB-tree s. Its features include infinite snapshots, multi-master operation, and self-healing.Features
* Keeps a full filesystem history, with settable pruning of old data.
* CRC checksumming of metadata.
* Minimal remount time (no fsck required).
* Designed for cluster mirroring and efficient remote access.
* Support for very large file-systems (up to 1 exabyte).
* Ability to re-optimize the layout in the background, on a live filesystem.Limitations
Requires a pruning/reblocking cron job run a few minutes every night to incrementally clean up and regain space on the filesystem.
Platforms
*
DragonFly BSD .References
* [http://leaf.dragonflybsd.org/cgi/web-man?command=hammer§ion=5 hammer(5)] Manpage.
* [http://leaf.dragonflybsd.org/cgi/web-man?command=hammer§ion=8 hammer(8)] Manpage.See also
*
List of file systems
*Comparison of file systems External links
* [http://www.dragonflybsd.org/hammer/ The HAMMER Filesystem] documentation page at DragonFly BSD
* [http://leaf.dragonflybsd.org/mailarchive/kernel/2007-10/msg00006.html HAMMER filesystem update - design document]
* [http://kerneltrap.org/HAMMER HAMMER-related articles] at KernelTrap
* [http://apollo.backplane.com/DFlyMisc/hammer01.pdf "THE HAMMER FILESYSTEM"] , Matthew Dillon, 21 June 2008
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