On 7/4/13 3:13 PM, "Brad Campbell" <lists2009@xxxxxxxxxxxxxxx> wrote: >On 05/07/13 02:30, Christoph Anton Mitterer wrote: >> Hi. >> >> Well for me personally these are follow up questions to my scenario >> presented here: http://thread.gmane.org/gmane.linux.raid/43405 >> >> But I think these questions would be generally interesting an I'd like >> to add them to the Debian FAQ for mdadm (and haven't found real good >> answers in the archives/google). >> >> >> 1) I plan to use dmcrypt and LUKS and had the following stacking in >> mind: >> physical devices -> MD -> dmcrypt -> LVM (with multiple LVs) -> >> filesystems > >I have two arrays with dmcrypt on top of MD. >Array 1 is 4 x Seagate 15k SAS drives in a RAID10 f2. >Array 2 is 6 x 240G SSD's in a RAID10 n2. > >Array 2 is partitoned. All run ext4. >The CPU is an AMD FX8350. I can max out all arrays with sequential or >random r/w loads. So dmcrypt is not a limiting factor for me. > >When I say max out, I run into bandwidth limits on the hardware before >dmcrypt gets in the way. > That is because your CPU has encryption features - the QNAP devices largely do not; I replaced the CPU in mine with one that had encryption features because otherwise there was nothing that could bring the performance above about 80MB/sec Once I put in a CPU supporting AESNI I could get up to about 500MB/sec - and this was still not CPU bound -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
