Re: Help specifying new web server/database machine

On 09/06/05, William Yu (wyu@talisys.com) wrote:
> Rory Campbell-Lange wrote:

> > ... Some have suggested that a single dual core processor is the way
> > to go. The RAM needs to fit the CPU arrangement too; William points
> > out that one needs 2 DIMMS per CPU.

> Your summary here just pointed out the obvious to me. Start with a 2P MB
> but only populate a single DC Opteron. That'll give you 2P system with
> room to expand to 4P in the future. Plus you only need to populate 1
> memory bank so you can do 2x1GB.

That makes sense. I should by a board with support for 2 Dual-core
Opterons, but only use one Opteron for the moment. Then I should buy
2x1GB RAM sticks to service that processor.

> > ... On a four-slot 1U server, would one do a single RAID10 over 4
> > disks 10000rpm U320 disks? I would run the database in its own
> > partition, separate from the rest of the OS, possible on LVM. An
> > LSI-Megaraid-2 appears to be the card of choice.
>
> With only 4 disks, a MegaRAID U320-1 is good enough. It's quite a
> premium to go to the 2x channel MegaRAID. With 4 drives, I'd still do 2
> big drives mirrored for the DB partition and 2 small drives for OS+WAL.

Should these all RAID1?

I'm a bit worried about how to partition up my system if it is strictly
divided between a system RAID1 disk entity and a DB disk entity, as the
proportion of web server content (images, movies, sounds) to actual
database data is an unknown quantity at the moment.

I typically keep all the database stuff in a /var logical partition and
for this project would expect to keep the web stuff under a /web logical
partition. I was thinking of using LVM to be able to shift around space
on a large (4 x 147GB RAID 1 or RAID10) raided volume. I appreciate that
this may not be optimal for the WAL transaction log.

Thanks for your comments;
Rory

--
Rory Campbell-Lange
<rory@campbell-lange.net>
<www.campbell-lange.net>