On Fri, 2009-04-17 at 07:05 -0400, Steve Dickson wrote: > > Kevin Constantine wrote: > > Trond Myklebust wrote: > >> On Wed, 2009-04-15 at 13:30 -0700, Kevin Constantine wrote: > >>> Has there been any effort to expose caching statistics to the end > >>> user? On the client-side, it would be useful to see how much data > >>> is being re-used from cache vs data that gets retrieved over the > >>> wire. Similarly on the server side, it would be nice to see how much > >>> data is being served from cache vs having to pull the data from disk. > >>> > >>> Just wondering if anyone started anything to expose this sort of > >>> information. > >> > >> See the nfs-iostat tool in the nfs-utils package: > >> > >> > >> http://git.linux-nfs.org/?p=steved/nfs-utils.git;a=tree;f=tools/nfs-iostat;h=929e303cc762a68dfd01546f5150eb294274164e;hb=refs/heads/master > >> > >> > >> Note that you need a 2.6.17 kernel or newer. > >> > >> Cheers > >> Trond > > > > Thanks Trond- > > > > It seems like nfs-iostat is displaying the number of pages that are > > being written to the read/write caches (i'm only looking at the > > client-side at the moment), and what I'm interested in is the ratio of > > pages being read from cache vs data being fetched from the server. > > > > Is there any documentation on the layout of /proc/self/mountstats? > No, unfortunately not... I'd suggest using the python code in nfs-iostat as a reference. You should be able to figure out how much data is being read on the wire by looking at nfs_stats['serverreadbytes']. Comparing that to the value in nfs_stats['normalreadbytes'] (which tells you the total number of bytes requested in read() calls) should give you a rough estimate for how much data is being read from cache. Cheers Trond -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
