>IOs have a variable size and for writing an object to a file with the aufs store, the OS write meta data to the file system log, updates the inode table and writes the data to a new file. So for aufs for one logical 'write object to disk' there are 3 IOs. I do not know the internals of rock fs but most likely only does one IO for each 'write object to disk'. < I do not think, that this is correct. For aufs it might be 3 "logical" IOs, which mean,s from the standpoint of view of application (i.e.squid/aufs). But because LINUX does a lot of bufffering/merging, in very rare scenarios these 3 "logical" IOs will be real "physical"IOs (disk accesses). For rock, the one "logical"IO does not necessarily result in one "physical" IO either. So, depending upon the size of the necessary storage, the amount of RAM, and tweaking the LINUX-fs, the number of physical IOs is much lower compared to the number of "logical" IOs, squid/aufs executes. (ext4 for example has a lot of knobs for performance tuning) -- View this message in context: http://squid-web-proxy-cache.1019090.n4.nabble.com/Hypothetically-comparing-SATA-SAS-to-NAS-SAN-for-squid-tp4664350p4664381.html Sent from the Squid - Users mailing list archive at Nabble.com.
