Thanks for pointing me to the right to look at. However, the main point is huge performance degradation while using sec=krb5 option instead of sec=sys. With sec=sys everything works as expected. Personally I simply can't find any reasonable explanation. BTW, I'm using Gentoo and getting the same error while using mountstats script. Regards, Vlad. On Wed, 2011-06-08 at 11:39 -0400, J. Bruce Fields wrote: > On Wed, Jun 08, 2011 at 08:26:17AM +0200, Vladimir Elisseev wrote: > > All of the accounts, except very limited amount, are in LDAP, and as I > > can see user information is identical on server and client. As for my > > tests, below are all the details. Difference in speed while copying a > > lot of small files is _huge_... I'd appreciate if somebody more familiar > > with NFS/kerberos combination can provide a kind of explanation. > > > > Regards, > > Vlad. > > > > * Local directory is /mnt/data/tmp/coreboot/src > > # find x86/ | wc -l > > 296 > > # du -csh x86 > > 1.5M x86 > > 1.5M total > > * First try without kerberos: grep /mnt/tmp/ /proc/mounts > > nfs:/mnt/tmp /mnt/tmp nfs > > rw,noatime,vers=3,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.1.219,mountvers=3,mountport=32767,mountproto=tcp,local_lock=none,addr=192.168.1.219 0 0 > > # time cp -i -arv /mnt/data/tmp/coreboot/src/arch/x86 /mnt/tmp/x86 > > cp -i -arv /mnt/data/tmp/coreboot/src/arch/x86 /mnt/tmp/x86 0.01s user > > 0.04s system 10% cpu 0.476 total > > > > * Second try with kerberos: grep /mnt/tmp/ /proc/mounts > > nfs:/mnt/tmp /mnt/tmp nfs > > rw,noatime,vers=3,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=krb5,mountaddr=192.168.1.219,mountvers=3,mountport=32767,mountproto=tcp,local_lock=none,addr=192.168.1.219 0 0 > > # time cp -i -arv /mnt/data/tmp/coreboot/src/arch/x86 /mnt/tmp/x86 > > cp -i -arv /mnt/data/tmp/coreboot/src/arch/x86 /mnt/tmp/x86 0.01s user > > 0.07s system 0% cpu 23.294 total > > So if I'm reading that right, the client isn't doing any more work, it's > just taking longer, so presumably it's spending more time waiting for > the server. > > Might be worth looking at /proc/self/mountstats to see which rpc's are > taking longer. > > (Chuck, what's up with the mountstats script? On a fedora 15 machine > with mountstats installed, it gives me "Statistics for mount point /mnt > not found", but > > # grep mnt /proc/self/mountstats > pip1:/exports/ mounted on /mnt with fstype nfs4 statvers=1.0 > > On a ubuntu machine running the mountstats out of > nfs-utils/tools/mountstats/mountstats.py, it runs without any output.) > > Might also be worth looking at vmstat or something on the server. > > --b. > > > > > > At the same time test with a single file (621M): > > * without kerberos: > > cp -i -av /mnt/media/images/GNOME_3.x86_64-0.2.0-Build1.1.iso 0.00s > > user 0.69s system 5% cpu 13.521 total > > * with kerberos: > > cp -i -av /mnt/media/images/GNOME_3.x86_64-0.2.0-Build1.1.iso 0.00s > > user 0.55s system 2% cpu 26.299 total > > > > With the same file, but with "dd > > if=/mnt/media/images/GNOME_3.x86_64-0.2.0-Build1.1.iso > > of=/mnt/tmp/test.iso bs=32M" > > gives: > > * without kerberos: 651165696 bytes (651 MB) copied, 10.7168 s, 60.8 > > MB/s > > * with kerberos: 651165696 bytes (651 MB) copied, 24.6176 s, 26.5 MB/s > > > > > > On Tue, 2011-06-07 at 19:07 -0400, J. Bruce Fields wrote: > > > On Fri, Jun 03, 2011 at 07:57:16PM +0200, Vladimir Elisseev wrote: > > > > There's no mount command involved in timing. It's simply copy of the > > > > same directory (with many small files to NFS share with and without > > > > sec=krb5 mount option. > > > > > > Weird. > > > > > > I wonder if the krb5 principal is being mapped to a different user on > > > the server side, and that's making some difference. > > > > > > Still, could you give us the full details? (Exactly what commands are > > > you running, what results do you see?) > > > > > > --b. > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
