Re: New server: SSD/RAID recommendations?

[Craig James <cjames@xxxxxxxxxxxxxx>]

On Wed, Jul 1, 2015 at 4:56 PM, Andreas Joseph Krogh <andreas@xxxxxxxxxx> wrote:

På torsdag 02. juli 2015 kl. 01:06:57, skrev Craig James <cjames@xxxxxxxxxxxxxx>:

We're buying a new server in the near future to replace an aging system. I'd appreciate advice on the best SSD devices and RAID controller cards available today.

 

The database is about 750 GB. This is a "warehouse" server. We load supplier catalogs throughout a typical work week, then on the weekend (after Q/A), integrate the new supplier catalogs into our customer-visible "store", which is then copied to a production server where customers see it. So the load is mostly data loading, and essentially no OLTP. Typically there are fewer than a dozen connections to Postgres.

 

Linux 2.6.32

Postgres 9.3

Hardware:

  2 x INTEL WESTMERE 4C XEON 2.40GHZ

  12GB DDR3 ECC 1333MHz

  3WARE 9650SE-12ML with BBU

  12 x 1TB Hitachi 7200RPM SATA disks

RAID 1 (2 disks)

   Linux partition

   Swap partition

   pg_xlog partition

RAID 10 (8 disks)

   Postgres database partition

 

We get 5000-7000 TPS from pgbench on this system.

 

The new system will have at least as many CPUs, and probably a lot more memory (196 GB). The database hasn't reached 1TB yet, but we'd like room to grow, so we'd like a 2TB file system for Postgres. We'll start with the latest versions of Linux and Postgres.

 

Intel's products have always received good reports in this forum. Is that still the best recommendation? Or are there good alternatives that are price competitive?

 

What about a RAID controller? Are RAID controllers even available for PCI-Express SSD drives, or do we have to stick with SATA if we need a battery-backed RAID controller? Or is software RAID sufficient for SSD drives?

 

Are spinning disks still a good choice for the pg_xlog partition and OS? Is there any reason to get spinning disks at all, or is it better/simpler to just put everything on SSD drives?

 

Thanks in advance for your advice!

 

 

Depends on you SSD-drives, but today's enterprise-grade SSD disks can handle pg_xlog just fine. So I'd go full SSD, unless you have many BLOBs in pg_largeobject, then move that to a separate tablespace with "archive-grade"-disks (spinning disks).

No blobs in our database, so that sounds like good advice. It simplifies the hardware a lot if we can go with just SSDs.

Craig

 

 

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Andreas Joseph Krogh

CTO / Partner - Visena AS

Mobile: +47 909 56 963

andreas@xxxxxxxxxx

www.visena.com

 

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Craig A. James

Chief Technology Officer

eMolecules, Inc.

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