On 08/12/2013 08:28 AM, David F. Skoll wrote:
Hi, We run a fairly write-intensive workload and are looking at upgrading our Pg servers. (PostgreSQL 9.1; no practical way to upgrade to 9.2 for a while because we use what's packaged with Debian.)
apt.postgresql.org
I'm considering the following configuration: Dual 4-core Intel CPU (E5620 at 2.4GHz) 192GB of RAM Sixteen 240GB Intel SSD 520 series drives arranged using Linux RAID-10. The RAID 10 array will use eight mirrored stripes using the "offset-copies" RAID10 scheme. Questions: 1) Has anyone had experience with Intel 520 SSDs? Are they reliable? When they fail, do they fail nicely (ie, failure detected and bad drive removed from RAID array) or horribly (data silently corrupted...) ?
I don't recall if the 520s have powerloss protection but you will want to check that.
2) Is this RAID arrangement sensible? I've seen reports where some people keep the pg_xlog directory on a separate RAID array, but I don't really see the advantage with SSDs.
Put the pg_xlog on spindles, they are more than fast enough and won't eat up the write life of your SSDs.
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