On Mon, Sep 29, 2008 at 06:01:18PM -0700, Jean Dion wrote: > Do you have dedicated iSCSI ports from your server to your NetApp?
Yes, it's a dedicated redundant gigabit network. > iSCSI requires dedicated network and not a shared network or even VLAN. > Backup cause large I/O that fill your network quickly. Like ans SAN today. > > Backup are extremely demanding on hardware (CPU, Mem, I/O ports, disk etc). > Not rare to see performance issues during backup with several thousands small > files. Each small file cause seeks to your disk and file system. > > As the number of files and size you will be impact. That means, thousand of > small files cause thousand of small I/O but not a lot of throughput. What statistics can I generate to observe this contention? ZFS pool I/O statistics are not that different when the backup is running. > Bigger your file are more likely the block will be consecutive on the file > system. Small file can be spread in the entire file system causing seeks, > latency and bottleneck. > > Legato client and server contains tuning parameters to avoid such small file > problems. Check your Legato buffer parameters. These buffer will use your > server memory as disk cache. I'll ask our backup person to investigate those settings. I assume that Networker should not be buffering files since those files won't be read again. How can I see memory usage by ZFS and by applications? > Here is a good source of network tuning parameters for your T2000 > http://www.solarisinternals.com/wiki/index.php/Networks#Tunable_for_general_workloads_on_T1000.2FT2000 > > The soft_ring is one of the best one. > > Here is another interesting place to look > http://www.solarisinternals.com/wiki/index.php/Solaris_Internals_and_Performance_FAQ Thanks. I'll review those documents. -- -Gary Mills- -Unix Support- -U of M Academic Computing and Networking- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
