[Maps-l] ptolemy partitioning

[Marcin Cieslak]

Ævar Arnfjörð Bjarmason wrote:
>> Partitioning the servers in an optimal manner for us is something I'm not as
>> comfortable with.  I could figure it out if necessary, but Saper is probably
>> better capable of that.  One thing I do know is that the database logs
>> should be on separate partition from the database itself, and both kept
>> separate from the OS.
> 
> I can't remember what sort of RAID setup we have. Depending on the
> RAID how we partition might not matter at all.

It's RAID 1+0 that means:

16 drives 140009MB each
every pair of drives is a mirror
everything is concatenated to be a single, large volume,
140009MB x 8 = 1120072 MB ~ 1119200 MB
is the logical volume we have (in fake megabytes)

> Without having tried it I wouldn't think that putting logging on a
> separate disk doesn't help that much. Logging doesn't take up so much
> I/O. However keeping the database and its indexes on separate disks
> evidently helps a lot. See recent discussions on osm-dev/talk about
> database setup.

We might move OS and software important stuff to a separate mirror (2
drives - but we waste 280GB for that then) and consider splitting the
rest for the DB purposes, keeping individual mirrors for safety and
concatenating as required for the database.

-- 
              << Marcin Cieslak // saper at saper.info >>

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