On 10 April 2013 00:16, Karol Babioch <karol@babioch.de> wrote:
Hi,
I've got four HDDs and added them into a RAID-5 array, which basically works just fine. However the performance sucks quite hard. I get only about 70 MB/s when it comes down to reading and writing speeds of about 35 MB/s.
The hardware itself is quite decent: Intel Xeon E31260L, 8 GB RAM and four Samsung HD204UI's. With the same setup and a Ubuntu live environment I get about 270 MB/s reading speed and 130 MB/s writing speed.
Therefore there must be a fundamental difference. I've compared various values from sysctl between both environments and set them accordingly, but to no availability.
Anyone else experiencing the same issues and/or can you point me in the right direction?
At least I would like to saturate my Gigabit Ethernet connection.
Best regards, Karol Babioch
I assume you're using Linux software RAID, although you don't mention. I've experienced this when using RAID6 and a suboptimal stripe cache size. Try tinkering with /sys/block/mdX/md/stripe_cache_size. In my case adjusting it to 8192 increased read and write speeds dramatically. Chris