Hello, this is my first post. I have become very interested in building an unRAID server. I've been reading and reading the forums. I'm trying to understand if parity and cache drives are completely separate from the drives for data? Do I need a cache drive? If so what size should they be if my data drives are 2Tb. I plan on maybe 5 drives to start out with. The main reason for I want a server is to stream video to a media player through a wired network. Also, I see there are a few versions of unRAID including a beta, what do you suggest I use?

Thanks,

Tom

Hello, this is my first post. I have become very interested in building an unRAID server. I've been reading and reading the forums. I'm trying to understand if parity and cache drives are completely separate from the drives for data?

They are separate

Do I need a cache drive?

No. I've had my server for 5 years and never used one. It was a band-aid for slow write speeds when earlier Linux kernels would only permit 9 or  10 MB/s write speeds.  Current kernels permit 30 to 35 MB/s write speeds with no cache drive.  The cache drive is ONLY needed if you must WRITE to the array faster than that.  It is not involved at all in improving speeds when reading from the array.

If so what size should they be if my data drives are 2Tb.

The cache drive would need to be able to hold a days worth of files you wanted to write quickly to the server.  If you copy one movie per day a 10Gig cache drive might work for you.

I plan on maybe 5 drives to start out with. The main reason for I want a server is to stream video to a media player through a wired network. Also, I see there are a few versions of unRAID including a beta, what do you suggest I use?

Thanks,

Tom

You should use 4.6rc2 right now.  It is stable and has no outstanding issues that will affect a new user of unRAID.  The 5.0beta is also fairly stable, but undergoing changes, and missing some features in the user-interface (the user interface, programming interface, and security is being changed as AFP is being added)  If you were not intending to use NFS it would work too, but I don't think the recent fix for "kernel-oops" has been applied to it, so it is actually a tiny bit behind 4.6rc2 as far as being stable.

 

Joe L.

Thanks Joe for helping me understand. I will forget the cache drive, at least for now. I will take your recommendations and use 4.6rc2. I'm going to spend the next couple of evenings picking out parts to order. Thanks again,

Tom