Hi List, I'm wondering if one of you expert DTrace guru's can help me. I want to write a DTrace script to print out a a histogram of how long IO requests sit in the service queue. I can output the results with the quantize method. I'm not sure which provider I should be using for this. Does anyone know? I can easily adapt one of the DTrace Toolkit routines for this, if I can find the provider.
I'll also throw out the problem I'm trying to meter. We are using ZFS on a large SAN array (4TB). The pool on this array serves up a lot of users, (250 home file systems/directories) and also /usr/local and other OTS software. It works fine most of the time, but then gets overloaded during busy periods. I'm going to reconfigure the array to help with this, but I sure would love to have some metrics to know how big a difference my tweaks are making. Basically, the problem users experience, when the load shoots up are huge latencies. An ls on a non-cached directory, which usually is instantaneous, will take 20, 30, 40 seconds or more. Then when the storage array catches up, things get better. My clients are not happy campers. I know, I know, I should have gone with a JBOD setup, but it's too late for that in this iteration of this server. We we set this up, I had the gear already, and it's not in my budget to get new stuff right now. Thanks for any help anyone can offer. Jon _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
