On Thu, Aug 28, 2008 at 3:01 PM, Łukasz Mierzwa <l.mierzwa@xxxxxxxxx> wrote: > Thursday 28 of August 2008 07:06:30 Krishna Srinivas napisał(a): >> On Wed, Aug 27, 2008 at 10:55 PM, Łukasz Mierzwa <l.mierzwa@xxxxxxxxx> > wrote: >> > Tuesday 26 August 2008 16:28:41 Łukasz Mierzwa napisał(a): >> >> Hi, >> >> >> >> I testing glusterfs for small files storage, first I've setup a single >> >> disk gluster server, connected to it from another machine and served >> >> those files with nginx. That worked ok, I got good performance, on >> >> average about +20ms slower for each request but that's ok. Now I've >> >> setup unify over afr (2 afr groups with 3 servers each, unify and afr on >> >> the client side, namespace dir is on every server, as other stuff afr'ed >> >> on the client side), this is mounted on one of those 6 servers. After >> >> writing ~200GB files from production server I started to do some tests >> >> and I've noticed that doing simple ls on that mount point causes as many >> >> writes as reads, this has to do something to either unify or afr, I >> >> suspect that those writes are do to namespace but I need to do more >> >> debugging. It's very annoying that simple reads are causing so many >> >> writes. All my servers are in sync so there should not be any need for >> >> sealf-healing. Before I start debugging it I wanted to ask if this is >> >> normal? Shoud afr or unify generate so many writes to namespace or maybe >> >> xattrs during reads (storage is on ext3 with users_xattrs on)? >> > >> > I tested it a little bit today and I found out that if I got 1 or 2 nodes >> > in my afr group for namespace there are no writes at all while doing ls, >> > if I add one or more nodes they are starting to get writes. WTF? >> >> Do you mean that your NS is getting write() calls when you do "ls"? > > It seems so. I will split my NS and DATA bricks to different disks today so I > will be 100% sure. What I am sure now is that I am getting as many writes as > reads when I do "ls" and have more than 2 NS bricks in AFR. > reads/writes should not happen when you do an 'ls' where are you seeing reads and writes being done? How are you seeing it? are you strace'ing the glusterfsd? Krishna
