I am building a LANcache for a lanparty that I'm organizing. We have about 80 visitors (pretty small LAN), but our uplink is limited to 100mb/s due to reasons and it's constantly saturated with game update/steam download traffic. A LANcache would probably help a lot. Our budget is not too large though.
At the moment I have composed a server with a 4Gbit/s network connection, and I want to fully saturate this connection with traffic, so that at least 4 people can download at gigabit speed simultaneously.
Now rests the question what kind of storage setup I need to serve 500MByte/s. The LANcache in the link above uses 6 SSD's in RAIDZ, and one of the authors actually says that 'for this use HDD’s really don’t cut it'.
However, a friend of mine tells me that using SSD's is overkill, and that ZFS on 3 HDD's with compression on and an SSD as cache should be able to deliver 500MByte/s. I'm wondering if this is true though, because
- The data is probably already compressed, since it's packages of game data
- Many articles/forum posts on the internet which I sadly cannot link because not enough reputation quote RAIDZ performance with 3 HDD's to be around 280MByte/s, and one (who is incidentally using it for a LANcache) specifically mentions not being able to saturate a 4 gigabit link
So my actual questions are
- Is it useful in the first place to use ZFS? Everyone seems to use it but a cache doesn't seem to have a lot of use for reliability to me...
- Is it useful to use RAID-Z as opposed to RAID-0?
- In my situation, would it be better to use SSD's?
- Is it possible to deliver 500MByte/s with the HDD based setup mentioned?
- If using ZFS, what kind of CPU/memory specs would i need?
