On Fri, Oct 10, 2003 at 05:48:55PM -0700, Jimmy Wales wrote:
One of the toughest decisions is which exact RAM to buy. 1GB pieces are a lot cheaper, and there are 8 total slots available. So I thought: buy 4 1GB pieces, and there's plenty of room for growth. When 2GB pieces drop in price (which I'm sure they will, and quickly), we have room for 8 gig more or 12 total. Or, if absolutely needed, we could move these 1GB pieces to other machines in our future network, and fill this server up to the full 16gig.
Sounds very wise. 4 Gigs should fit the current need and is open for future increase.
For the RAID, I selected 4x36gig in a RAID 5 array, for a logical drive capacity of 105 gig. I also selected 1 extra hot spare drive, just for that much more added reliability. There are many other possibilities for this, and I'm open to recommendations. My impression is that with RAID 5, more drives means more performance, but with enough RAM, we shouldn't be hitting the drives that hard anyway.
When doing RAID 5, all two SCSI channels have to work properly. If one fails (e.g. one drive doing some noise on the SCSI cable, one controler chip broken), than the entire RAID will be inaccessible. The RAID 5 configuration can't cover this.
A RAID 0+1 configuration, with data striped over two disks on one adapter and mirrored to the other adapter, is more reliable and probably a little bit faster.
Regards,
JeLuF