[DRBD-user] DRBD w/RAID5 - Ubuntu Server

Stefan Seifert nine at detonation.org
Sun Aug 17 15:07:12 CEST 2008

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

On Tuesday, 12. August 2008, Todd Denniston wrote:
> Stefan Seifert wrote, On 12/23/-28158 02:59 PM:
> > Also: never put a drbd meta disk on a MD RAID 5. Its painfully slow (and
> > may be a reason for what you see). RAID 1 should be ok.
> I would think that putting the meta data in a separate partition, which is
> not in the data disk (array) would be sensible even if using no RAID, as
> seeking issues seem to have been a common thread in many of the recent 'how
> do I speed up drbd' list messages.  Or is this what you meant by 'never put
> a drbd meta disk on a MD RAID..."?

That's exactly what I meant. From what I gathered in the last 8 months on this 
mailing list, RAID 5 has just too high a latency due to too many seeks for 
use as a drbd _meta_ disk. RAID 5 as data disk seems to be ok. The optimum 
seems to be a completely seperate disk for meta data, which can be a RAID 1.


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