[squid-users] High load server Disk problem

Hi.

I'm using squid on a high speed network (with 110M of http traffic).

I'm using 2.7.STABLE7 with these cache_dir:

cache_dir aufs /cache 756842 60 100
cache_dir coss /cache/coss1 65520 max-size=1048575
max-stripe-waste=32768 block-size=4096 membufs=15
cache_dir coss /cache/coss2 65520 max-size=1048575
max-stripe-waste=32768 block-size=4096 membufs=15
cache_dir coss /cache/coss3 65520 max-size=1048575
max-stripe-waste=32768 block-size=4096 membufs=15

Everything works fine most of the day, but on peak hours, I got these:

2010/08/17 20:06:59| squidaio_queue_request: WARNING - Disk I/O overloading
2010/08/17 20:06:59| squidaio_queue_request: Queue Length:
current=981, high=1488, low=321, duration=170

After a while, I got a few of these, with "duration" increasing, until:

2010/08/17 20:23:09| squidaio_queue_request: WARNING - Disk I/O overloading
2010/08/17 20:23:09| squidaio_queue_request: Queue Length:
current=558, high=2177, low=321, duration=531

The web browsing started to get very slow, which is when the support
team took squid down.

All cache_dir are on a single sata-2 7200RPM 1TB hard drive.

Is there a way to know which cache_dir is the problem and what I can
so this doesn't happen?

I tried using both 16 and 32 AIO threads, but didn't help.

cache manager tells me that I have around 10 million objects:

Average HTTP requests per minute since start: 18851.1

Storage Swap size: 693535688 KB
Storage Mem size: 30872 KB
Mean Object Size: 64.50 KB

Internal Data Structures:
10752896 StoreEntries
   49 StoreEntries with MemObjects
   26 Hot Object Cache Items
10752847 on-disk objects

Please help!

- Robert
Received on Wed Aug 18 2010 - 02:56:55 MDT