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<blockquote type="cite"><br>
> Is there anything that you guys can suggest I do around the cache? <br>
> Should I try a different store type? A different filesystem type<br>
> perhaps?<br>
> <br>
> <br>
> <br>
> If your store has a configuration knob that effectively limits disk <br>
> writing rate, then use it to limit that rate to avoid overflowing the<br>
> queue.<br>
> <br>
> You can also consider using rock store that has an explicit write<br>
> rate limiting option (but comes with other problems that may or may<br>
> not affect your setup).<br>
> <br>
> Adding more physical disk spindles helps, of course.<br>
> <br>
<br>
Just to be clear since you mentioned working with virtual services. By<br>
"spindle" Alex refers to individual physical HDD devices underneath the<br>
whole VM storage setup. 'Disk' a the VM level, even at the RAID level<br>
might refer to multiple or overlapping (shared) 'spindles'.<br>
<br>
Unless your AUFS/UFS/diskd cache_dir are limited to being on one<br>
"spindle" HDD, they can cause a shared HDD controller to fill up /<br>
overload and adding more cache_dir just makes that particular problem worse.<br>
<br>
Amos<br>
<br>
</blockquote>
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<blockquote type="cite"></blockquote>
<div>Hi Amos</div>
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<div>At the time of my email my cache_dir was a 100GB disk assigned from the same datastore as where the VM is. I have to say that I never had problems with this setup. The storage is provided from a IBM XIV storage unit so it's not the slowest of storage devices.
After some discussions with a couple of people we thought that perhaps the cache is too big, so I now made it 4 x 15GB aufs cach_dirs. 2 Disks are from the same datastore as the VM, and 2 are from a datastore assigned to the cluster from a SVC (XIV behind
it) with the following in my squid.conf.</div>
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<div><span style="font-family: monospace; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">maximum_object_size_in_memory
</span><span style="font-family: monospace; color: rgb(178, 24, 24); background-color: rgb(255, 255, 255);">256</span><span style="font-family: monospace; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"> KB </span></div>
<div><span style="font-family:monospace"><span style="color:#b26818;background-color:#ffffff;">maximum_object_size</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">4096</span><span style="color:#000000;background-color:#ffffff;"> MB
</span><span style="color:#000000;background-color:#ffffff;"> </span><br>
store_dir_select_algorithm least-load <br>
<br>
<span style="color:#b26818;background-color:#ffffff;">cache_dir</span><span style="color:#000000;background-color:#ffffff;"> aufs /var/cache/squid-c1/
</span><span style="color:#b21818;background-color:#ffffff;">10240</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">32</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">256</span><span style="color:#000000;background-color:#ffffff;">
</span><br>
<span style="color:#b26818;background-color:#ffffff;">cache_dir</span><span style="color:#000000;background-color:#ffffff;"> aufs /var/cache/squid-c2/
</span><span style="color:#b21818;background-color:#ffffff;">10240</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">32</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">256</span><span style="color:#000000;background-color:#ffffff;">
</span><br>
<span style="color:#b26818;background-color:#ffffff;">cache_dir</span><span style="color:#000000;background-color:#ffffff;"> aufs /var/cache/squid-c3/
</span><span style="color:#b21818;background-color:#ffffff;">10240</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">32</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">256</span><span style="color:#000000;background-color:#ffffff;">
</span><br>
<span style="color:#b26818;background-color:#ffffff;">cache_dir</span><span style="color:#000000;background-color:#ffffff;"> aufs /var/cache/squid-c4/
</span><span style="color:#b21818;background-color:#ffffff;">10240</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">32</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">256</span><span style="color:#000000;background-color:#ffffff;">
</span><br>
cache_replacement_policy <span style="color:#b21818;background-color:#ffffff;">heap</span><span style="color:#000000;background-color:#ffffff;"> lfuda
</span><br>
<span style="color:#b26818;background-color:#ffffff;">memory_replacement_policy</span><span style="color:#000000;background-color:#ffffff;">
</span><span style="color:#b21818;background-color:#ffffff;">lru</span><br>
<span style="color:#000000;background-color:#ffffff;"></span><br>
</span></div>
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<div>Do you think this is optimal?</div>
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