I’d posted before about how my ‘dream computer setup’ would have a big fileserver with a bunch of disks… Something like 4-8 SATA drives, 7200 RPM, running RAID 5. The net result is several terabytes of storage, and, since RAID 5 provides striping, excellent performance.
It would have to be delivered over Gigabit Ethernet, since 100 Mbps caps out at 12.5 MB/sec (100 Mbps / 8 bits to a byte).
Running something like OpenFiler, it would “speak” most all protocols, allowing me to have shares for Windows, Linux, and Mac machines merrily get along… (I’d also like to make it, for once, highly organized! Have a “share” for music, and another for photos I’ve taken, etc.)
I just had another idea, though…The main advantage of this setup was to keep everything in one place, so I can get to my music or photos from any PC. But I soon realized that a stripe set over GigE could exceed the performance of an internal hard drive, where 20-30 MB/sec maximum throughput is considered good.
The hard bottleneck is GigE at 125MB/sec. (Although, unless you’re someone like my dad and start doing interrupt- and driver-level optimization, you might not get more than 85% of so of the rated line, with overhead and all.) A couple of SATA drives striped won’t hit that. But why not try to make GigE your bottleneck?
There are tons of used servers and related equipment on eBay these days. So pick up a couple of smaller (18-36?) GB SCSI disks. 15K RPM. Quite a few claim to exceed 100MB/sec, with some closer to 200MB/sec. You could be really conservative since you’re buying used hard drives and use RAID 1 (mirroring), but let’s live on the edge and say we get three of them and use RAID5. (Or get 2 and use RAID 0…. Or 4 and RAID 1+0.) And while we’re on eBay, let’s pick up a used SCSI RAID controller to keep things fast.
So we now have a fileserver with terabytes of space that’s probably faster than your hard drive, and we now have, depending on how crazy you felt, a partition of between 18 and 72GB that’s capable of at least 100MB/sec speeds. What do we use it for?
Well, first of all, anything that you think of that you want to be really fast. If you’re net-booting machines, put ’em in there. (That would be an interesting experiment, actually: speed is normally not thought of as a reason to do network boots.) If you have some essential file that you work with, keep it in there.
But I envision this more as a spot of short-term storage. The first thing that comes to mind is Photoshop’s scratch disk. You get better performance (when you’re using it) if it’s on a separate hard drive. Set it up there.
But then I got an even neater idea… Your paging file performs much better if it’s on a separate disk. I’m fairly certain that Windows won’t let you use a network share as your paging file. (It won’t let you use a USB drive, although they merrily let you set up the paging file there, it just never actually creates it.) However, Openfiler and Vista Business (at least) seem to support iSCSI with no problem… Are you seeing what I’m thinking? Tell Windows it can keep a 4GB page file on your S: drive, which is actually a SCSI stripe set on another machine… I wonder if, though iSCSI, Windows would allow this. (There is a decent reason not to allow it: it would be somewhat bad if your paging file, located on a remote machine, went away. However, I maintain that, especially if you used RAID, the odds aren’t that much greater than of your hard disk crapping out on you.)
I’ve got to get a job so I can afford to try this out! 😉