Re: [dm-crypt] Improving performance?

[Markus Krainz <ldm@gmx.at>]

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On 2010-11-11 19:26, Lasse Jensen wrote:
> I havent tested my current setup this way, but my old setup, RAID 
> first, then encryption worked fine.

RAID first, den ecryption works for me, too.
But testing the ecrypting drives seperately, then RAID approach failed.
What good is fast performance if the RAID 5 does not work? :D

>     dmcrypt/luks is used on top of the raid. The performance of the i5
>     is not great, despite hardware aes. Should not be this numbers a
>     bit higher than 158 MB/sec?
>
>     ~/httptunnel-3.3/ hdparm -t --direct /dev/md1
>
>     /dev/md1:
>      Timing O_DIRECT disk reads:  936 MB in  3.00 seconds = 311.67 MB/sec
>
>     ~/httptunnel-3.3/ hdparm -t --direct /dev/mapper/evol
>
>     /dev/mapper/evol:
>      Timing O_DIRECT disk reads:  476 MB in  3.01 seconds = 158.30 MB/sec
>
>     cat /proc/cpuinfo | grep -E (model name|aes)
>     model name      : Intel(R) Core(TM) i5 CPU         660  @ 3.33GHz
>     flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
>     pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
>     pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts
>     rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64
>     monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2
>     popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority ept vpid
>
>
> Well, it's still a lot better than my setup. Have you got any idea how 
> much power your system uses idle and under load?
>

I am afraid I cannot unplug the server right now and I do not have an 
ampere meter lying around.
But I went for a 32nm dual-core-CPU, a small motherboard with lots of 
sata plugs and an efficient power supply, so I figured you can not get 
much better power
consumption wise.

Forgot to mention, the above hdparam -t result is for cipher mode: 
xts-plain64 and AES-256.

Regards,

Markus Krainz


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