Re: [squid-users] Squid high bandwidth IO issue (ramdisk SSD)

Well, from what I've read, SSDs don't necessarily provide very high
random write throughput over time. You should do some further research
into how they operate to understand what the issues may be.

In any case, the much more important information is what IO pattern(s)
are occuring on your storage media and what the controller is doing
with it. You still haven't eliminated the possibility that the
controller/driver is somehow not helping.

You should also graph at least read/write IO count and byte counts;
investigate what is going on.

2c,

Adrian

2009/8/2 smaugadi <adi_at_binat.net.il>:
>
> Dear Waitman,
>
>
> Testing the SSD drive, before installing it on the squid, showed huge
> performance advantage in IOPS, read/write. So, I thought that this will
> solve the problems I had with HDD.
> But it was not so, look at this output:
> 12:39:35 PM  CPU   %user   %nice    %sys %iowait    %irq   %soft  %steal
> %idle    intr/s
> 12:39:37 PM  all    2.87    0.00    2.25   44.44    0.12    3.50    0.00
> 46.82  11666.50
> 12:39:37 PM    0    0.00    0.00    0.00    0.00    0.50    4.50    0.00
> 95.00   4764.00
> 12:39:37 PM    1    0.00    0.00    0.50    4.98    0.00    2.49    0.00
> 92.04   2097.50
> 12:39:37 PM    2   11.56    0.00    8.54   76.88    0.00    3.02    0.00
> 0.00   1977.50
> 12:39:37 PM    3    0.50    0.00    0.00   95.52    0.50    3.48    0.00
> 0.00   2827.50
>
> This is a moment before the system went down, the IO is up high.
>
>
> Waitman Gobble-2 wrote:
>>
>>
>> smaugadi wrote:
>>> Dear ALL,
>>> We have a squid server with high volume of traffic, 200 – 300 MB
Received on Sun Aug 02 2009 - 09:48:52 MDT