In the last few weeks we started serving more and more videos by http, ranging from 50 to 500mb each, and as we didn't had a new server to use it just for that i set it up on our live streaming server.
The box is pretty decent imho (2 x quad at 2ghz, 4gb ram, 4 x 300gb sas 15k rpm in hw RAID1, running Linux 2.6, ext3 fs with deadline scheduler, nginx as webserver) but we still had issues with delivering the files, mainly i suspect because our iowait was ranging from 10 to 45% and util was around 90% most of the times, while cpu was around 20-30%.
From what i've read that should've hold our ~300-400mbps traffic, but it doesn't..
Being on a budget we can't rely on a CDN but we can get more processing power if needed and the datacenter can handle our traffic.
Now we got a new server that should do only this but i don't know what would be the best way to setup it, main questions for now being:
- what raid level would suit this task more? now have 4 x 300gb + 2 x 146gb, both SAS at 10k rpm, hw raid, would like more space but redundancy is also important
- how would i expand it later, lvm a good idea?
- how much ram would it need, for now it has 16gb but can add more if it would give us a decent boost, any tips with it?
- decided on xfs for filesystem, anything against/better suited for this?
- how much could i rely on only this 1 server?
Any other advices are appreciated.