[geeks] Journaled Filesystems (thanks to sunhelp.org)

[Martijn Pronk]

Bill Bradford wrote:

>On Thu, Apr 11, 2002 at 02:18:02AM -0400, Joshua D Boyd wrote:
>
>>Doesn't it make for slower writes?
>>
>
>If anything, it seems *faster*.  Postfix is definitely faster on a logging
>filesystem.
>
It may be because it's SoftUpdates with a new name? (See the softupdates URL
in my other mail in this thread)

According to one of the tests done with softupdates Sendmail performed 
very much better
than with a sync mounted filesytem. Softupdates makes metadata updates 
very fast.
Furthermore, if the computer looses power or crashed, softupdates can
find out at the next fsck what it was doing without reading a log (just 
by looking at the state of the superblock, inodes and directory 
entries.) Also with a softupdates enabled computer one
can make a snapshot of the filesystem and use that to fsck. (FreeBSD 
current (5.0) can do this)

The only thing softupdates doesn't do anything about is the content of 
files.  It's only trying to keep the filesystem in a sane state.

Martijn