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Diffstat (limited to 'sys/ufs')
-rw-r--r-- | sys/ufs/ffs/README.softupdates | 58 |
1 files changed, 0 insertions, 58 deletions
diff --git a/sys/ufs/ffs/README.softupdates b/sys/ufs/ffs/README.softupdates deleted file mode 100644 index 3b9c675..0000000 --- a/sys/ufs/ffs/README.softupdates +++ /dev/null @@ -1,58 +0,0 @@ -$FreeBSD$ - -Using Soft Updates - -To enable the soft updates feature in your kernel, add option -SOFTUPDATES to your kernel configuration. - -Once you are running a kernel with soft update support, you need to enable -it for whichever filesystems you wish to run with the soft update policy. -This is done with the -n option to tunefs(8) on the UNMOUNTED filesystems, -e.g. from single-user mode you'd do something like: - - tunefs -n enable /usr - -To permanently enable soft updates on the /usr filesystem (or at least -until a corresponding ``tunefs -n disable'' is done). - - -Soft Updates Copyright Restrictions - -As of June 2000 the restrictive copyright has been removed and -replaced with a `Berkeley-style' copyright. The files implementing -soft updates now reside in the sys/ufs/ffs directory and are -compiled into the generic kernel by default. - - -Soft Updates Status - -The soft updates code has been running in production on many -systems for the past two years generally quite successfully. -The two current sets of shortcomings are: - -1) On filesystems that are chronically full, the two minute lag - from the time a file is deleted until its free space shows up - will result in premature filesystem full failures. This - failure mode is most evident in small filesystems such as - the root. For this reason, use of soft updates is not - recommended on the root filesystem. - -2) If your system routines runs parallel processes each of which - remove many files, the kernel memory rate limiting code may - not be able to slow removal operations to a level sustainable - by the disk subsystem. The result is that the kernel runs out - of memory and hangs. - -Both of these problems are being addressed, but have not yet -been resolved. There are no other known problems at this time. - - -How Soft Updates Work - -For more general information on soft updates, please see: - http://www.mckusick.com/softdep/ - http://www.ece.cmu.edu/~ganger/papers/CSE-TR-254-95/ - --- -Marshall Kirk McKusick <mckusick@mckusick.com> -July 2000 |