Jean-David Beyer wrote:
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Willo van der Merwe wrote:
Richard Huxton wrote:
Willo van der Merwe wrote:
Hi guys,
I'm have the rare opportunity to spec the hardware for a new database
server. It's going to replace an older one, driving a social
networking web application. The current server (a quad opteron with
4Gb of RAM and 80Gb fast SCSI RAID10) is coping with an average load
of ranging between 1.5 and 3.5.
The new machine spec I have so far:
What's the limiting factor on your current machine - disk, memory,
cpup?
I'm a bit embarrassed to admit that I'm not sure. The reason we're
changing machines is that we might be changing ISPs and we're renting /
leasing the machines from the ISP.
Before you get rid of the current ISP, better examine what is going on with
the present setup. It would be good to know if you are memory, processor, or
IO limited. That way you could increase what needs to be increased, and not
waste money where the bottleneck is not.
Good advice. After running a vmstat and iostat, it is clear, to my mind
anyway, that the most likely bottleneck is IO, next is probably some
more RAM.
Here's the output:
procs -----------memory---------- ---swap-- -----io---- --system--
----cpu----
r b swpd free buff cache si so bi bo in cs us sy
id wa
0 0 29688 80908 128308 3315792 0 0 8 63 6 8 17
2 80 1
avg-cpu: %user %nice %sys %iowait %idle
17.18 0.00 1.93 0.81 80.08
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 14.57 66.48 506.45 58557617 446072213
sda1 0.60 0.27 4.70 235122 4136128
sda2 0.38 0.77 2.27 678754 2002576
sda3 2.37 0.49 18.61 429171 16389960
sda4 0.00 0.00 0.00 2 0
sda5 0.71 0.66 5.46 578307 4807087
sda6 0.03 0.01 0.24 6300 214196
sda7 0.02 0.00 0.19 2622 165992
sda8 60.19 64.29 474.98 56626211 418356226
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