Re: [Scst-devel] [ANNOUNCE]: Comparison of features sets betweendifferent SCSI targets (SCST, STGT, IET, LIO)

From: Tomasz Chmielewski
Date: Sat Apr 04 2009 - 15:12:58 EST


Vladislav Bolkhovitin schrieb:
Hi All,

I set up http://scst.sourceforge.net/comparison.html page, which compares features of existing SCSI target subsystems for Linux. The comparison includes SCST, STGT, IET and LIO.

I might be not fully correct somewhere, so, if you don't agree with me about some item(s) in the comparison table, please let me know and I will fix that.

Performance is a bit debatable.


I made some simple SCST and STGT tests last week, there were some where SCST won, there were some where STGT won.

What was surprising to me, although STGT has a bigger CPU impact than SCST, STGT was faster when reading from an encrypted (dm-crypt) volume, on a system where the CPU is the bottleneck (it can't decrypt as fast as HDD can deliver data).

STGT was much slower when reading from a non-encrypted volume, when target had "blockdev --setra 16384 ..." for a given target.
On the other hand, STGT was faster than SCST with default blockdev readahead settings (256).

If anyone's interested, I can show results in a readable form on Monday (right now, I have only raw data which is pretty long and would be hard to compare).



--
Tomasz Chmielewski
http://wpkg.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/