Re: [zfs-discuss] Re: ZFS over NFS extra slow?
Roch - PAE wrote: I've just generated some data for an upcoming blog entry on the subject. This is about a small file tar extract : All times are elapse (single 72GB SAS disk) Local and memory based filesystems tmpfs : 0.077 sec ufs : 0.25 sec zfs : 0.12 sec NFS service that can end up corrupting client's view of data: nfs/ufs : 7 sec (write cache enable) nfs/zfs : 4.2 sec (write cache enable, zil_disable=1) nfs/zfs : 4.7 sec (write cache disable, zil_disable=1) NFS service that will not corrupt the client's view: nfs/ufs : 17 sec (write cache disable) nfs/zfs : 12 sec (write cache disable, zil_disable=0) nfs/zfs : 7 sec (write cache enable, zil_disable=0) That is very interesting data since it actually has ZFS being faster that UFS in all cases which isn't what I've heard people claim. If you haven't already done so it would be interesting to add UFS/SVM in there as well just for "completeness". It would also be interesting to see how each RAID style compares here and what the numbers are when "rewritting" the files (for example unpack the tar file on top of itself rather than into a "fresh" filesystem). -- Darren J Moffat ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Re: ZFS over NFS extra slow?
I've just generated some data for an upcoming blog entry on the subject. This is about a small file tar extract : All times are elapse (single 72GB SAS disk) Local and memory based filesystems tmpfs : 0.077 sec ufs : 0.25 sec zfs : 0.12 sec NFS service that can end up corrupting client's view of data: nfs/ufs : 7 sec (write cache enable) nfs/zfs : 4.2 sec (write cache enable, zil_disable=1) nfs/zfs : 4.7 sec (write cache disable, zil_disable=1) NFS service that will not corrupt the client's view: nfs/ufs : 17 sec (write cache disable) nfs/zfs : 12 sec (write cache disable, zil_disable=0) nfs/zfs : 7 sec (write cache enable, zil_disable=0) ZFS numbers tend to have more variability from run to run than UFS. I still need to plow through the data to figure a few things out. Watch this space for more info... -r ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Re: ZFS over NFS extra slow?
write cache was enabled on all the ZFS drives, but disabling it gave a negligible speed improvement: (FWIW, the pool has 50 drives) (write cache on) /bin/time tar xf /tmp/vbulletin_3-6-4.tar real 51.6 user0.0 sys 1.0 (write cache off) /bin/time tar xf /tmp/vbulletin_3-6-4.tar real 49.2 user0.0 sys 1.0 ...this is a production system, so I attribute the 2-second (4%) difference more to variable system activity than to the write cache. I suppose I could test with larger samples, but since this is still ten times slower than I want, I think this effectively discounts the disk write cache as anything significant. This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Re: ZFS over NFS extra slow?
Ah, thanks -- reading that thread did a good job of explaining what I was seeing. I was going nuts trying to isolate the problem. Is work being done to improve this performance? 100% of my users are coming in over NFS, and that's a huge hit. Even on single large files, writes are slower by a factor of 2 to 10 compared to if I copy via scp or onto a non-zfs filesystem. Thanks! This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
