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Re: Load-Average with different backends on different filesystems
> On one server the load average went up to somewhere between 30 and 50,
> but all other machines (same config, similar amount of LDAP access and
> searches) stayed around 0. The only difference between the machines is
> the filesystem: with xfs, ext2 and ext3 there are no problems, but with
> reiserfs there is no productive use possible (at least with default
So it would seem pretty clear this is a kernel/reiserfs bug, or in fact
that system is using different library versions (these subtle differences
are hard to spot).
And, IMHO, your nuts using reiserfs on a production system - but whatever.
> After googling a bit I found out that it is known that the system does
> not perform fast on journaling filesystems and bdb with inproper cache
> settings, but since most accessing operations (max. one write per min)
> are read that should be no problem (especially if it performs well with
> other filesystems).
That it doesn't perform well with "improper cache settings" should be
self-evident. It performs JUST FINE on a journalled filesystem, I doubt
there is anyone left not using a journaled filesystem. You can of course,
tune your filesystems if the system is partitioned properly.
> After looking a while into Doc and FAQ I didn't find anything that
> states that there may be some filesystems that should not be used with
> bdb (but there are some postings in the archive), so maybe this info
> should be included somewhere.
It shouldn't make a huge difference unless the filesystem (driver,
or structure on disk) is itself broken.
> After switching back to ldbm on this server all things are fine again.
> And hopefully I'll find the time to migrate the machine to xfs...