[PVFS-users] pvfs performance analysis

[Jeremy Enos]

I'm curious how your tests would perform with version 1.6.0.  I had a SHARP 
performance drop when going to any version past 1.6.0...  but all my tests 
were at or beyond the scale where your problems show up.

         Jeremy

At 03:11 PM 4/19/2004, Martin Margo wrote:
>I got a couple of questions regarding PVFS performance.
>
>my settings:
>20 servers, each has a dual 1.5 Ghz Madison (ia64) processors
>running suse sles8
>kernel 2.4.21_144
>running pvfs 1.6.2
>disk configuration, each node has dual 73 GB IBM SCSI drives,
>         PVFS is setup on the second drive.
>
>we tried using two configurations
>
>configuration 1:
>         1 node as mgr,iod,client
>         12 nodes as iod and client
>         7 nodes as iod
>
>configuration 2:
>         1 node as mgr, iod
>         1 node as iod
>         12 nodes as clients
>
>
>
>1. Based on my observation using IOR to benchmark PVFS (2 cases, case1
>with 20 iod, case 2 with only 2 iod) i  saw that the write performance
>is roughly half of the read performance. This seems normal but do you
>know exactly what is causing this?
>2. Based on the same settings as above, my read performance dropped
>significantly for I/O greater than 256 MB for configuration 2 and 1 GB for
>configuration 1. Now this number (256mb, and 1 gb are per node). We
>used 12 clients for these tests, so the performance is dropping sharply
>after aggregate of 3 GB at configuration 2 and after 12 GB aggregate on 
>configuration 1. Does it have
>anything to do with congestion, load, etc? Is this common?
>3. PVFS read performance dropped again when I did my scaling test (each
>client write 1 GB  unique file to pvfs in configuration 2. I varied the
>clients from 2 to 12 nodes, and read performance decreased sharply
>after 6 clients from 200MB/s into 50 MB/s aggregate.
>
>Thanks in advance.
>
>-Martin W. Margo
>
><br>
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