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Write Ahead Physical Block Logging (WAPBL) provides meta
data journaling for
file system
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...
s in conjunction with
Fast File System Fast File System may refer to:
* Berkeley Fast File System, as used by the various BSD variants
* Amiga Fast File System
The Amiga Fast File System (abbreviated AFFS, or more commonly historically as FFS) is a file system used on the Amiga pe ...
(FFS) to accomplish rapid filesystem consistency after an unclean shutdown of the filesystem and better general use performance over regular FFS. 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.
History
WAPBL was initially committed into NetBSD in 2008, and first appeared with NetBSD 5.0 (2009).
With NetBSD 6.0 (2012), ''
soft updates
Soft updates is an approach to maintaining file system meta-data integrity in the event of a crash or power outage. Soft updates work by tracking and enforcing dependencies among updates to file system meta-data. Soft updates are an alternative t ...
'' (known as ''soft dependencies'' in NetBSD) was removed in favour of ''WAPBL''.
See also
*
Log-structured file system
*
Soft updates
Soft updates is an approach to maintaining file system meta-data integrity in the event of a crash or power outage. Soft updates work by tracking and enforcing dependencies among updates to file system meta-data. Soft updates are an alternative t ...
*
Unix File System (UFS/FFS)
References
External links
*
*
*
Computer file systems
Disk file systems
NetBSD
Unix file system technology
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