Re: SSD + RAID

Am 13.11.2009 um 14:57 schrieb Laszlo Nagy:

> I was thinking about ARECA 1320 with 2GB memory + BBU.
> Unfortunately, I cannot find information about using ARECA cards
> with SSD drives.
They told me: currently not supported, but they have positive customer
reports. No date yet for implementation of the TRIM command in firmware.
...
> My other option is to buy two SLC SSD drives and use RAID1. It would
> cost about the same, but has less redundancy and less capacity.
> Which is the faster? 8-10 MLC disks in RAID 6 with a good caching
> controller, or two SLC disks in RAID1?
I just went the MLC path with X25-Ms mainly to save energy.
The fresh assembled box has one SSD for WAL and one RAID 0 with for
SSDs as table space.
Everything runs smoothly on a areca 1222 with BBU, which turned all
write caches off.
OS is FreeBSD 8.0. I aligned all partitions on 1 MB boundaries.
Next week I will install 8.4.1 and run pgbench for pull-the-plug-
testing.

I would like to get some advice from the list for testing the SSDs!

Axel
---
axel(dot)rau(at)chaos1(dot)de PGP-Key:29E99DD6 +49 151 2300 9283 computing @
chaos claudius