>Rock and COSS storage types however are far more optimized for speed, using both disk and RAM storage in ther normal "disk" configuration. < Amos, haven't you been a little bit too "generous" in your comments, especially this referred one ? I looked at the docs both for COSS and Rock, and the following excerpts made me a bit skeptical: 1) COSS: Changes in 3.3 cache_dir COSS storage type is lacking stability fixes from 2.6 When I read such a statement, I refuse to use this feature in a production environment. Even in case, it has a lot of speed advantages. One crash might wipe out all speed advantages. 2) Rock: http://wiki.squid-cache.org/Features/RockStore#limitations 2a) Rock store is available since Squid version 3.2.0.13. It has received some lab and limited deployment testing. It needs more work to perform well in a variety of environments, but appears to be usable in some of them. 2b)Objects larger than 32,000 bytes cannot be cached when cache_dirs are shared among workers. 2c)Current implementation uses OS buffers for simplicity. When reading 2a) I start to be cautious again :-) 2b) tells me, it very much depends upon the mean size/standard deviation of the cached objects, whether using Rock really has an advantage. Might change in the future with Rock-large, though. 2c) Makes the theoretical approach to evaluate performance advantages of Rock almost impossible. Because you always have to consider the filesystem used, with the respective options, having a huge impact on performance. So the only serious approach right now to advocate possible performance advantages would be after quite some benchmarking, using real workloads. Which certainly are very site specific. Because of the basic principle of Rock and Rock-large (which are like filesystems themselves), using raw disk-I/O is possible in the future, at least, which MIGHT THEN justify a general statement "much more optimized to speed". -- View this message in context: http://squid-web-proxy-cache.1019090.n4.nabble.com/Squid-3-2-6-hot-object-cache-tp4658133p4658154.html Sent from the Squid - Users mailing list archive at Nabble.com.