istgt now supports command queuing in disk type
aoyama at peach.ne.jp
Sun Mar 22 17:31:20 PDT 2009
New release was uploaded in my blog.
The command queuing improves especially sequential read
by MCS(multiple connections per session) round robin.
In my post, I uploaded the screen shots using CrystalDiskMark
which is one of popular benchmark in Japan.
You can download CrystalDiskMark(multilingual) from:
I got the result about 1.5x-3x faster than previous 20090314.
If test data was cached, it reached over 200MB/s.
Known Issue and Limitations:
o queuing is only supported in single initiator environment.
o LUN thread might have deadlock when an error has occurred.
o write command is still slow.
o timeout may occur when using MCS.
o single connection may be slower than without queuing.
Here is release 20090323:
The screen shots show difference between QueueDepth 16 and 0
The command queuing is disabled by default.
If you want to use it, please add QueueDepth key in the LogicalUnit
section of your configuration. for example:
# Queuing 0=disabled, 1-255=enabled with specified depth.
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