[CentOS] Why is yum not liked by some?

Bryan J. Smith b.j.smith at ieee.org
Wed Sep 7 23:14:19 UTC 2005


Les Mikesell <lesmikesell at gmail.com> wrote:
> I've had a couple of boxes with Reiserfs crash recently
> from UPS problems and multiple times they have refused to
> mount without a fsck with --rebuild-tree, which takes a
> full day or so.  I thought the point of journaling was to
> avoid needing that...

Avoid?  Yes.
Eliminate?  Impossible.

Journaling helps _avoid_ full filesystem integrity checks. 
But the only way to absolutely check if a filesystem is
completely consistent is with a full filesystem integrity
check.

In fact, the "better" journaling filesystems know when _not_
to trust their own journals.  ReiserFS is actually very
_good_ from that standpoint, it would rather not reply a
journal it does not believe that is good.

But that's only half the issue.  A journaling filesystem must
_also_ have good off-line recovery tools -- i.e., the
off-line fsck utility itself.

> Is there any reason to expect better from xfs? 

XFS' structure hasn't changed since the mid-'90s -- over a
decade.  So while its on-line journaling reliability might be
debated (among other journaling filesystems), it's off-line
"xfs_repair" is trusted as much as e2fsck.

Both JFS and ReiserFS have had signficant structural changes
in the last few years.  ReiserFS itself is actually designed
to be very fluid.  While that's fine for its on-line
functionality, including the journaling, when it goes
off-line, I don't put my trust in the fsck.reiserfs tool to
be "in sync" with the latest on-line developments.

> These are running backuppc and need better-than-ext3
> performance at creating/removing files.

If performance is your bag, then ReiserFS pleases in many
areas -- including deletion.  XFS absolutely stinks when your
filesystem is lot of small, constantly changing files -- and
excels better when there are large files as well as small
(including extents and delayed writes for fighting
fragmentation).


-- 
Bryan J. Smith                | Sent from Yahoo Mail
mailto:b.j.smith at ieee.org     |  (please excuse any
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