Write Ahead Physical Block Logging

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

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 shutdown in an unclean fashion.[3]

History[edit]

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[edit]

References[edit]

  1. ^ Wasabi Systems Inc. (2008). "Wasabi JFS".
  2. ^ a b Federico Biancuzzi (2008-05-18). "NetBSD WAPBL". O'Reilly Media. Retrieved 2019-03-24.
  3. ^ a b The NetBSD Foundation, Inc. (2008–2012). "WAPBL(4) — Write Ahead Physical Block Logging file system journaling". BSD Cross Reference. NetBSD. Lay summary.CS1 maint: Date format (link)
  4. ^ The NetBSD Foundation, Inc. (2015). "WAPBL(9) — write-ahead physical block logging for file systems". BSD Cross Reference. NetBSD. Lay summary.
  5. ^ The NetBSD Foundation, Inc. (2008). "sys/wapbl.h". BSD Cross Reference. NetBSD.
  6. ^ The NetBSD Project (2009-04-29). "Announcing NetBSD 5.0". NetBSD. Some highlights are: a preview of metadata journaling for FFS file systems (known as WAPBL, Write Ahead Physical Block Logging)
  7. ^ The NetBSD Project (2012-10-17). "Components removed from NetBSD". Announcing NetBSD 6.0. NetBSD. “softdep” support is no longer available in FFS; use wapbl(4) logging instead.
  8. ^ Adam Hamsik (2009-02-23). "Soft dependencies removed". NetBSD.

External links[edit]