[gentoo-user] NFS terribly slow on writes
Hi, on one of our students' lab the home directories of the students are mounted via NFS. Our main application (www.codelite.org) seems to write a lot of small chunks to files in the students' home directories. Thus, just finishing Codelite takes 100 seconds while the same version on a pure local machine takes about 2 seconds for that. A simple test dd bs=80 count=1 if=/dev/zero of=$HOME/Test shows only 80 Kb/sec (speed of a floppy drive). The machine was idle and connected to a dedicated, nearly idle server by a network of 1Gb/sec. Does anybody have some hints on how to speed up such an NFS3 setup? Many thanks for some clues. By the way, NFS was set up with the async option. Helmut.
Re: [gentoo-user] NFS terribly slow on writes
Hi Helmut, this is common problem with nfs. I would suggest investigate more about nfs4 (better caching). And try to play with mount options rsize=1024,wsize=1024. I think default is 8k. Robert. V Fri, 20 Apr 2012 20:29:57 +0200 Helmut Jarausch jarau...@igpm.rwth-aachen.de napsáno: Hi, on one of our students' lab the home directories of the students are mounted via NFS. Our main application (www.codelite.org) seems to write a lot of small chunks to files in the students' home directories. Thus, just finishing Codelite takes 100 seconds while the same version on a pure local machine takes about 2 seconds for that. A simple test dd bs=80 count=1 if=/dev/zero of=$HOME/Test shows only 80 Kb/sec (speed of a floppy drive). The machine was idle and connected to a dedicated, nearly idle server by a network of 1Gb/sec. Does anybody have some hints on how to speed up such an NFS3 setup? Many thanks for some clues. By the way, NFS was set up with the async option. Helmut.
Re: [gentoo-user] NFS terribly slow on writes
On Fri, Apr 20, 2012 at 2:29 PM, Helmut Jarausch jarau...@igpm.rwth-aachen.de wrote: Hi, on one of our students' lab the home directories of the students are mounted via NFS. Our main application (www.codelite.org) seems to write a lot of small chunks to files in the students' home directories. Thus, just finishing Codelite takes 100 seconds while the same version on a pure local machine takes about 2 seconds for that. A simple test dd bs=80 count=1 if=/dev/zero of=$HOME/Test shows only 80 Kb/sec (speed of a floppy drive). The machine was idle and connected to a dedicated, nearly idle server by a network of 1Gb/sec. Does anybody have some hints on how to speed up such an NFS3 setup? There's all kinds of NFS tuning options. I'm not an expert, so I can't really make any strong suggestions, but my first stop would probably be grabbing the ebook version of http://shop.oreilly.com/product/9781565925106.do and giving that a good couple hours' deep skim. -- :wq
Re: [gentoo-user] NFS terribly slow on writes
the biggest things to think about: - nfs versions (some work better or are more compatible with others) - nfs write/read cache settings - use nfsstat to get an idea of what the nfs traffic is like - is filesystem constantly having locking issues or refreshing file attributes? might need to change mount options. - if not local lan, might have significant problems...especially with mtu - doesn't hurt to check iostat -x -k 5 on sending server too along with nic card stats - it usually isn't that hard to track down where the problem lies - I've had great performance with nfs over local lans, horrible issues with any kind of remote nfsnewer nfs versions are trying to work around the issues. On Fri, Apr 20, 2012 at 1:34 PM, Michael Mol mike...@gmail.com wrote: On Fri, Apr 20, 2012 at 2:29 PM, Helmut Jarausch jarau...@igpm.rwth-aachen.de wrote: Hi, on one of our students' lab the home directories of the students are mounted via NFS. Our main application (www.codelite.org) seems to write a lot of small chunks to files in the students' home directories. Thus, just finishing Codelite takes 100 seconds while the same version on a pure local machine takes about 2 seconds for that. A simple test dd bs=80 count=1 if=/dev/zero of=$HOME/Test shows only 80 Kb/sec (speed of a floppy drive). The machine was idle and connected to a dedicated, nearly idle server by a network of 1Gb/sec. Does anybody have some hints on how to speed up such an NFS3 setup? There's all kinds of NFS tuning options. I'm not an expert, so I can't really make any strong suggestions, but my first stop would probably be grabbing the ebook version of http://shop.oreilly.com/product/9781565925106.do and giving that a good couple hours' deep skim. -- :wq -- Matthew Marlowe m...@professionalsysadmin.com https://www.twitter.com/deploylinux 1-805-857-9144
