> > -----Original Message----- > > From: john allspaw [mailto:jallspaw@xxxxxxxxx] > > yes, we're using squid in a farm with very high performance requirement, > > as it's doing http acceleration for our origin servers. we're replacing > > 2disk SATA with 6disk SCSI, and while I gather there are diminishing > > returns with adding over 3 or 4 spindles, having a decent cache size is > > probably second in importance. > > > > we'll be going from 2 cache_dirs of 10Gb each to 6 cache_dirs (one on > > each disk) with 5Gb each. our cache_mem size is 2048mb, which puts us > > just over the 10mb/1Gb mem-to-disk suggestions, but the boxes have 4Gb > > of On 12.09 09:55, Chris Robertson wrote: > As I understand it, squid only populates cache_mem with newly requested > objects (not objects from disk), so if you restart Squid, that 2GB of RAM > is going to lay fallow. Using a smaller cache_mem allows the OS to use > the rest of the memory to cache disk hits. If they have 40% mem hit ratio, I wouldn't decrease cache_mem. I would try to decrease maximum_object_size_in_memory a bit and/or use memory_replacement_policy heap GSDF to try get bigger % of memory hits for smaller files and to reduce disk seeks (they are the slowest part) but I would be very carefull when doing this and check what impact it has on efficiency and performance. depending on network utilisation and data on webservers I would try set up those caches as neighbours and configure multicast ICP between them, maybe on separate subnet > > ok, from what you're both saying, I might not have to worry > > about where to put the 5Gb partitions on these drives, but > > basically, it can't hurt. I've been going on the assumption > > that the most important performance gains will come from 1) > > the xtra spindles, and 2) the better seek times on the 15K > > SCSI (versus 7200k SATA) drives. you should simply put all partitions on start of disks -- Matus UHLAR - fantomas, uhlar@xxxxxxxxxxx ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. Atheism is a non-prophet organization.
