On Thursday 10 July 2003 16.17, Peter Smith wrote: > I am wondering if having cache_dir drives on a RAID controller that > has Read/Write cache turned on might cause problems?
Depends on the RAID level and the load you plan on putting on the RAID. > I'm fairly sure that Squid manages the latency, etc of its > cache_dir drives. Nope, but if a lot of requests get queued for the drive then Squid backs off (applies to aufs and diskd drivers only, not ufs). > The drives that my Squids use are all on RAID controllers as single > volumes. However I recently found that if I enable Read/Write > cache on the cache_dir drives that load on the processor goes off > the scale. Do this RAID controller have embedded CPU for the buffer management etc, or do it use the main CPU? > Could it be that Squid gets such a quick response from > the drive that it thinks the drive is super fast and thus slams it, > causing it to run out of Read/Write cache and then gets overloaded > as the requests backlog? Not very likely. But on the other hand, if your Squid previously was throttled by the disk I/O due to the lack of buffers then enabling the cache may speed things up, allowing Squid to catch up on the traffic and thus use more CPU. -- Donations welcome if you consider my Free Squid support helpful. https://www.paypal.com/xclick/business=hno%40squid-cache.org If you need commercial Squid support or cost effective Squid or firewall appliances please refer to MARA Systems AB, Sweden http://www.marasystems.com/, [EMAIL PROTECTED]