Hi John, On Thu, Jul 17, 2008 at 5:09 PM, John Marshall <John.Marshall@xxxxxxxx> wrote: > Raghavendra G wrote: > >> Hi John, >> >> Please find the inlined comments. >> >> On Thu, Jul 17, 2008 at 2:53 AM, John Marshall <John.Marshall@xxxxxxxx<mailto: >> John.Marshall@xxxxxxxx>> wrote: >> >> Hi, >> >> I was testing out the glusterfs "type cluster/stripe" and saw in >> the output: >> ----- >> 2008-07-16 22:48:12 D [fuse-bridge.c:1604:fuse_writev_cbk] >> glusterfs-fuse: 169275: WRITE => 131072/131072,21474185188/21474316260 >> 2008-07-16 22:48:12 D [fuse-bridge.c:1641:fuse_write] >> glusterfs-fuse: 169276: WRITE (0x80560b0, size=131072, >> offset=21474316260) >> ----- >> Whether the client is configured with "option block-size *:4MB" or >> "option block-size *:1MB" does not seem to change what appears >> above to be write() operations of 128KB at a time. Am I understanding >> this correctly? >> >> >> "option block-size " is specific to cluster/stripe xlator. It determines >> the size of the chunks the file has to be sliced into and distributed among >> stripe's children. It does not affect the sizes in which fuse does >> writes/reads. >> > Is there any way to change the size of the writes/reads? Have you done any > tests to see the impact of going to a larger value than 128KB? > Will get back to you about this. > > As a side question, must the block-size remain the same for the life of the > filesystem? I.e., if the fs was used with block-size of 4MB, then mounted > later with 1MB, would this mess things up? > If the back-end file-system supports extended attributes, Changing of block-size should not be a problem, since stripe stores the block-size at the time of file creation as an extended attribute. It then uses the stored attribute value in further reads/writes. Otherwise, the block-size should remain the same for the life of the file-system. > Thanks, > John > regards, -- Raghavendra G A centipede was happy quite, until a toad in fun, Said, "Prey, which leg comes after which?", This raised his doubts to such a pitch, He fell flat into the ditch, Not knowing how to run. -Anonymous
