> -----Original Message----- > From: centos-bounces at centos.org > [mailto:centos-bounces at centos.org] On Behalf Of Jean Figarella > Sent: Wednesday, June 06, 2007 12:14 PM > To: CentOS mailing list > Subject: Re: [CentOS] NFS v4 > > Les Mikesell wrote: > > Jean Figarella wrote: > > > >>>> Under real user load though it just fell on its arse very > >>>> quickly and a quick fall back to v3 was implemented. Maybe the > >>>> EL5 implementation behaves better? > >>> > >>> I use one of my CentOS 5 boxen for low-load fileserver with > >>> NFS4. I've been noticing that although MP3s plays fine from > >>> that box, it can take a minute or two to write a dozen > >>> tags--something that should happen in the blink of an eye. I've > >>> been wondering what the problem is. Maybe it's NFS4! > >>> > >> > >> I've been experiencing 5 to 20 seconds freezes ever since > I upgraded > >> my nfs server. This serves about 30 people. Anytime > someone writes a > >> big file to their home directory, the freezes happen. You can > >> experience the freezes when browsing the internet, I guess because > >> firefox is constantly writing data (cache, cookies, etc...). Other > >> apps freeze up too. > >> > >> Now the question on my side is: can I force centos4 for > serve nfs3 as > >> opposed to nfs4. If I am not mistaken this is dependent on > the client? > >> > >> The reason Im asking is that if I can force the server to > serve nfs3 > >> then the clients will default to nfs3 themselves. right? > > > > Are these mounted with the sync or async option? If it is > sync, the > > client waits for the physical flush to disk to happen on every > > operation, something that is horribly slow and that you > never do for > > local disks except for transaction boundaries in databases > and other > > unusual situations. > > > > At first the sync option was being used, and the freezes > happened very > frequently. About a month and a half ago I started using > async, and now > I get far fewer freezes, like maybe 3 in an 8hr span. You can also couple the async with the anticipatory scheduler so reads will get higher priority then writes which can help readers during a page-cache flush. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.