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

[Tomasz Chmielewski <mangoo@wpkg.org>]

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