[Dovecot] linux 2.4 vs 2.6 kernel

[Matthias Andree]

Chris Wakelin <c.d.wakelin at reading.ac.uk> writes:

> I'm at the once bitten stage with Reiserfs, unless someone knows how to 
> deal with bad blocks short of 'dd'-ing to another disk and back - the 
> disk won't remap the bad sectors unless you try to write to them and its 
> not trivial to find out how!

badblocks in non-destructive read-write mode - but it can take many
hours to complete depending on how many blocks are broken and how many
retries the drive performs. RAID helps against bad blocks, at the
expense of write speed. It doesn't help against kernel bugs (SuSE Linux
9.2 megaraid driver - avoid SUSE 9.2 on megaraid at all cost unless you
know how to build a driver update! I haven't looked at 9.3 yet, 9.1 was
fine AFAIR)

> Having said that, SuSE uses it as the
> default, so we've gone with that on our SuSE installs so far.

SUSE have special patches in their kernels so reiserfs supports the ext3
"data=ordered" and "data=journal" semantics, the default/vanilla
reiserfs operates in the same metadata-only journal mode as do XFS and
JFS. SUSE also enable the write barrier stuff by default, whereas it
defaults to off in vanilla kernels (leaving aside the fact it requires
fairly recent kernels to work).

-- 
Matthias Andree