On Wed, Jun 30, 2004 at 12:47:07PM -0500, Gregory Gulik wrote: > Date: Wed, 30 Jun 2004 12:47:07 -0500 > From: Gregory Gulik <greg@xxxxxxxxx> > To: For users of Fedora Core releases <fedora-list@xxxxxxxxxx> > Subject: Re: VERY slow NFS FC2 -> RH9 > Reply-To: For users of Fedora Core releases <fedora-list@xxxxxxxxxx> > > > Actually, I think I got it. I removed the "sync" from the options and > it sped up immediately. The copy now took 2 seconds. > > Hmm, I've been using that option for quite a while, probably at least > since this client was on RH9 but only upon upgrading to FC2 did I find > NFS performance to be this poor. > > At least the problem is solved. Thanks! Well make sure to make a note in your system notebook about turning off the sync option. I have mixed opinions on the sync bit. I have never found data corruption issues that matter with modern uptimes but toggling this bit is one of the classic benchmark tricks. If specific data integrity requirements justifies then you will want to set it back. Some data base files need it. Other tuning tricks have to do with matching read and write sizes to the data chunkieness. Also file locking... I think you had a Rhine controller. I have problems with my cheap switch and this controller in full duplex. Switching to half duplex solved my packet loss and speeds then ran at 100BaseT(HD) speeds. If some of the NFS sync reply packets were getting lost then things slow down a lot. For me scp was ok, but rsync was not when I was running in full duplex mode. Anyhow when you see retransmit packets in tethereal or tcpdump output between local systems switch from FD to HD and see if it helps. -- T o m M i t c h e l l /dev/null the ultimate in secure storage.
