HI Murali Thanks for your help these days! I do some improve of Samba write over PVFS2. And 2 IO nodes,1 client node can provide 160MB/s write performance from Samba clients now.
But the Samba read performance is not good,just 80MB/s. :( 1.PVFS2 client seems not use the read cache,Can I use it? 2.Can I use the "readahead" in PVFS2? 3.What shall I do,modify any PVFS2 source code? Please give me some advice,thanks so much.wait for your letter. Thank you Murali. Best regards -------------------------------------------------- > Hi Jiang, > > > HI Murali, > > I test the write performance just on pvfs2 client with big > blocks,the> performance seems good. > > and I test samba with COPY form windows clients to local disk(JBOD) > > without pvfs2,the local file system is XFS,and the write > performance is > > good too.about 100MB/s. > > But when I add the pvfs2 file system,the write performance is > bad,just> 20MB/s. > > Hmm.. This definitely seems to indicate that Samba over PVFS2 uses > verysmall block sizes.. > > > 1.you said " Due to the absence of any client-side caches, > multiple round > > trips ensues and performance drops.",shall I use the client-sid > caches?How> can I use it ? > > Nope. We haven't implemented this yet. > > > 2.you said "Can you check if the smbd server uses pvfs2 writev > function> instead of write? (perhaps by strace'ing the server?)", > > How can I check it ? > > If the samba server is a UNIX userspace process, could you start > up the > samba server like so > strace -f -o /tmp/log.txt -e file /path/to/smbd <arguments> > AFter the server is started, remount samba on all clients and redo > yourtests. > > Check the contents of the file /tmp/log.txt and see if there are > calls to > writev or write()?If there are calls to write(), check the sizes > of the > system call arguments.. > Hopefully that will point us to the problems and possibly solutions. > THanks, > Murali > > > Thank for help me very much! > > > > Best regards > > ---------------------------------------------- > > > > ----- Original Message ----- > > From: "Murali Vilayannur" <[EMAIL PROTECTED]> > > Cc: <[email protected]> > > Sent: Monday, September 25, 2006 11:43 PM > > Subject: Re: [Pvfs2-users] Samba over PVFS2 performance > > > > > >> Hi Philips, > >> > >> > I met a Samba over PVFS2 prolem.So would anybody help me > please?>> > I use the pvfs2 file system and export the files > with Samba.The > >> hardware are two JBOD with > >> > 146G 10k FC disk, 4 pvfs2 IO servers,8 pvfs2 clients and some > >> windows clients.Every IO server > >> > manages 6+1 RAID5.the stripe size is 64k. > >> > My problem is that How can we tuning the read/write > performance of > >> this system ? > >> > this architecture,I test the performance with 2G > files.and find > >> the read performance is fast,but the > >> > write performance is bad.Would you tell me what should > be care > >> about Samba over PVFS2? > >> > >> Can you verify whether PVFS2 performance (no Samba export, just > native>> PVFS2) is bad on your setup first? What > >> benchmark did you use to measure the performance on your system? > >> Just wanted to make sure that it is a pvfs2 performance problem > and not > >> a > >> samba tuning issue.. > >> > >> I suspect what might happen with writes is that the VFS/smbd > writes out > >> single pages and hence PVFS2 sees only 4K/8K bytes at a time. > >> Due to the absence of any client-side caches, multiple round trips > >> ensues > >> and performance drops. > >> Can you check if the smbd server uses pvfs2 writev function > instead of > >> write? (perhaps by strace'ing the server?) > >> thanks, > >> Murali > >> > > > > > > > _______________________________________________ Pvfs2-users mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
