Kyle <[EMAIL PROTECTED]> writes:
> The software I can tune myself. I was more looking for Linux specific tuning.
>
> * Yes, I was/am concerned about I/O.
> * But also ensuring the OS itself (system processes) is not hindering anything
> otherwise.
Unless you are running other processes on the system you can be
reasonably confident that early performance measurement will tell you if
the OS is responsible for problems.
> * The RAID is the storage medium. (Hardware RAID)
You /really/ need to let us know what brand and configuration; 3ware and
Areca have very different performance characteristics; the presence or
absence of a BBU is going to be key, also.
In general, there is a reasonable chance you will find the RAID5
performance of your hardware solution disappointing, and if you can move
to something closer to a RAID10 you will, in general, have better
results.
> * Incremental change analysis is done client side.
Does the data just sit on this system, or is it sent somewhere else
afterwards? (In other words, is this just a big, reliable hard disk?)
Does this require reading the previous backup, or is it purely date
based?
Do you have a backup window?
> * Dual P4's / 1GB RAM
> * Filesys is ext3 mounted with 'defaults'
You will probably find performance here disappointing. XFS with a
2.6.24 or more recent kernel will do better, perhaps significantly so.
Otherwise you would want to look for tips on tuning an ext3 filesystem
to be less conservative about performance or, if you can carry the risk,
use ext2, to deliver better write performance.
For a write-only load where the server is, essentially, a big and
reliable hard disk for the backup software then, basically, you don't
have a lot of tuning to do.
The RAID layout and filesystem choices are the only real points to
consider tuning up front -- and, probably, enabling LVM for ease of
future management of volume space.[1]
For 3ware, at least, and probably for other hardware controllers, you
can gain significantly by tuning the queue depth, in line with the
vendors recommendations.
Finally, test, test, test. Get something as close as possible to your
real load running and identify where the bottleneck is.
[...]
>> You have not even given enough information about what you intend to use
>> it for:
>>
>> * what parts of performance are you concerned about?
>> * what is the backup software?
>> * how does it get data from the clients?
>> * where does it spool that data temporarily?
>> * where does it store it finally?
>> * what compression, format transformation, etc happens to the data?
>> * what filesystem are you planning to use, and is that fixed?
>> * can you use something other than RAID5?
>> * is it software RAID, hardware, or FakeRAID?
>> * What sort of dual CPU is it -- two sockets, two cores, or one HT CPU?
>> * how much memory do you have?
Regards,
Daniel
Footnotes:
[1] Depending on your hardware RAID brand you may be able to grow a
live array, in which case you have more or less the same
flexibility that LVM would give you.
--
SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/
Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
