Write Ahead Physical Block Logging
Write Ahead Physical Block Logging (WAPBL) provides meta data journaling for file systems in conjunction with Fast File System (FFS) to accomplish rapid filesystem consistency after an unclean shutdown of the filesystem and better general use performance over regular FFS.[1][2][3][4] With the journal, fsck is no longer required at system boot; instead, the system can replay the journal in order to correct any inconsistencies in the filesystem if the system has been shut down in an unclean fashion.[3]
History
WAPBL was initially committed into NetBSD in 2008, and first appeared with NetBSD 5.0 (2009).[5][2][6]
With NetBSD 6.0 (2012), soft updates (known as soft dependencies in NetBSD) was removed in favour of WAPBL.[7][8]
See also
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References
- ↑ Wasabi Systems Inc. (2008). "Wasabi JFS". http://www.wasabisystems.com/technology/wjfs.
- ↑ 2.0 2.1 Federico Biancuzzi (2008-05-18). "NetBSD WAPBL". O'Reilly Media. http://broadcast.oreilly.com/2009/05/netbsd-wapbl.html.
- ↑ 3.0 3.1 The NetBSD Foundation, Inc. (2008–2012). "WAPBL(4) — Write Ahead Physical Block Logging file system journaling". NetBSD. http://bxr.su/n/share/man/man4/wapbl.4.
- ↑ The NetBSD Foundation, Inc. (2015). "WAPBL(9) — write-ahead physical block logging for file systems". NetBSD. http://bxr.su/n/share/man/man9/wapbl.9.
- ↑ The NetBSD Foundation, Inc. (2008). "sys/wapbl.h". NetBSD. http://bxr.su/n/sys/sys/wapbl.h.
- ↑ The NetBSD Project (2009-04-29). "Announcing NetBSD 5.0". NetBSD. //www.netbsd.org/releases/formal-5/NetBSD-5.0.html. "Some highlights are: a preview of metadata journaling for FFS file systems (known as WAPBL, Write Ahead Physical Block Logging)"
- ↑ The NetBSD Project (2012-10-17). "Components removed from NetBSD". Announcing NetBSD 6.0. NetBSD. //www.netbsd.org/releases/formal-6/NetBSD-6.0.html#removals. ""softdep" support is no longer available in FFS; use wapbl(4) logging instead."
- ↑ Adam Hamsik (2009-02-23). "Soft dependencies removed". NetBSD. //blog.netbsd.org/tnf/entry/soft_dependencies_removed.
External links
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