On Wed, 2006-07-12 at 21:23 +0100, Murata, Dennis W (SAIC) wrote: > I am seeing something very similar to the problem Greg has stated. We > are using udp rather than tcp as the transport protocol. Should we be > using tcp rather than udp? That seems to be the recommendation. I am > testing configuration with tcp with the following arguments: > > DAEMONOPTIONS="--timeout=60 > rsize=32768,wsize=32768,tcp,timeo=600,retrans=2,bg"
Oh .. don't background mount in autofs this will lead to problems. > > We are using automount for all the nfs directories, nothing is listed in > the /etc/fstab. The nis maps are legacy from Solaris, and we still use > Solaris NIS servers. I am little reluctant to modify the maps > themselves if I don't have to. Will this work using the DAEMONOPTIONS > in /etc/sysconfig/autofs? From the mount command I see: > > nfsserver:/vol/vol1/home/foo on /home/foo type nfs > (rw,nosuid,rsize=32768,wsize=32768,tcp,timeo=600,retrans=2,bg,intr,retry > =1000,vers=3,addr=XXX.XXX.XXX.XXX) > > The entry from /proc/mounts does not list the values for timeo or > retrans: > > nfsserver:/vol/vol1/home/foo /home/foo nfs > rw,nosuid,v3,rsize=32768,wsize=32768,hard,intr,tcp,lock,addr=nfsserver 0 > 0 > > Is this normal? > > Wayne Murata > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Trond Myklebust > Sent: Tuesday, July 11, 2006 6:28 PM > To: [EMAIL PROTECTED] > Cc: [email protected]; [EMAIL PROTECTED] > Subject: Re: [NFS] bug in linux mount? (says NetApp) > > > On Tue, 2006-07-11 at 14:00 -0500, Gregory Baker wrote: > > We have thousands of linux clients hitting netapp file servers (many > > 3500 series, clustered) on a local gigabit LAN. From time to time, > > applications return "file not found" when attempting to automount a > > directory and access a file. An example of this is a long running > > process, which reads in data, processes it for hours (in which time > the > > filesystem is unmounted) then tries to read more data from that mount > > point (which causes a "file not found" error in the application). > This > > occurs about 1/100th of the time. > > > > Researching at Netapp turns up this bit by Chuck Lever (Linux NFS > > contributer) > > > > "Using the Linux NFS Client with Network Appliance Filers" > > http://www.netapp.com/libr ary/tr/3183.pdf (February 2006) > > > > page 10 says... > > > > "Due to a bug in the mount command, the default retransmission timeout > > > value on Linux for NFS over TCP is quite small...To obtain standard > > behavior, we strongly recommend using "timeo=600, retrans=2" > explicitly > > when mounting via TCP." > > > > Our defaults (assuming man pages are correct, RedHat Enterprise Linux > 3) > > would be timeo=7, retrans=3, which translates to 7+14+28+56 = 105 > tenths > > of a second (10 seconds). It appears netapp is suggesting waiting > > 600+600 = 1200 tenths (120 seconds) before giving up on the mount > command... > > No they are not. See below. > > > * What "bug" in the mount command do you believe NetApp is talking > about? > > It has nothing to do with the mount timeout: Chuck is talking about the > retransmission timeout for TCP connections 'timeo' which should indeed > be set to a high value since TCP guarantees message delivery (unlike UDP > which requires a small timeo value). Setting it too low means that you > end up spamming your server with a load of unnecessary retransmissions. > > This was indeed the case for some older versions of 'mount' and also for > older versions of the am-utils/amd automounters. > > > * What do you think proper options for NFS auto/mounts would be for > > extremely busy centralized NFS filers? > > Something like > > mount -t nfs -ohard,timeo=600,retrans=2,rsize=32768,wsize=32768,tcp > foo:/ /bar > > should be a fairly safe bet. You might want to add the 'intr' flag too, > depending on how you feel about the behaviour w.r.t. pressing ^C. > > > * What is the reference standard behavior? > > To which reference are you referring? > > Cheers, > Trond > > > > ------------------------------------------------------------------------ > - > Using Tomcat but need to do more? Need to support web services, > security? > Get stuff done quickly with pre-integrated technology to make your job > easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache > Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > NFS maillist - [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/nfs > > _______________________________________________ > autofs mailing list > [email protected] > http://linux.kernel.org/mailman/listinfo/autofs _______________________________________________ autofs mailing list [email protected] http://linux.kernel.org/mailman/listinfo/autofs
