[NEW BUILD] Help With A New Build

[thejammonster]

I am planning a build mostly using parts from my existing gaming PC.  I have a few questions that came up along the way and I'd like to get them answered before I order anything.  Any help is appreciated.

 

Current Parts

Intel i7 4770K

MSI Z87 mATX Motherboard

32GB G.Skill DDR3 1600 RAM

256GB Samsung 840 Pro SSD

2TB Western Digital Black HDD

SeaSonic 750W PSU

 

- The "new build" sticky says to use "green" drives unless there is a "specific need" for 7200 RPM drives.  What would that specific need be?  I was thinking of 3x 2TB WD Green drives with my existing 2TB WD Black as the parity drive.  Would 3 more WD Black drives be preferrable?  In what application?

- I was planning to use my 256GB SSD as a cache drive.  If I got another 256GB SSD and created a cache pool, is that simply parity (RAID 1) for my cache drive, or are there other benefits?

- Is there any need for a CD/DVD drive?  I know the OS boots from a USB drive, but I'll have a spare drive left over.

- The last question is regarding the case.  I have a 12U Tripp Lite wall-mounted, enclosed rack (SRW12USG) that I would like to put this server into.  I am looking for recommendations on a 3U or 4U rackmount case taking into account the mATX motherboard, ATX PSU, and the specs of my cabinet.  The cabinet is a standard 19" 4-post rack but the mountable depth is only 20.5".  This makes the maximum depth I am looking for around 15", which seems to be the next standard depth down from ~20".  The options I have found so far with 15" cases have been Norco/Habey, iStarUSA, and ARK (which seems to just be iStarUSA re-branded in many cases).  iStarUSA and ARK seem to rely on a flimsy C-shaped piece of metal for their HDD "cages".  In their cases that are more substantial they only seem to have at most 4 internal 3.5" drive bays.  The best option I have found is the Norco RPC-431.  Does anyone have any other recommendations, taking my need for a shorter case into consideration?  I'd like to keep the cost under $300 (preferably much lower) so that rules out SUPERMICRO and some others.

 

Thanks again for any input!

[garycase]

A 2nd SSD isn't "parity" => it creates a RAID-1 mirror.  But the idea's the same ... yes, it would give you a fault-tolerant cache, so files you write to UnRAID will be fault tolerant as they're written instead of some hours later when the mover script runs.

 

Green drives are fine ... the faster drive for parity will help when you're doing multiple simultaneous writes to the array => but even that is essentially mitigated by use of a cache.  The only downside I see to what you're thinking about is the restricting of drive sizes to 2TB due to your current WD Black.    If the cost isn't prohibitive, I'd buy new larger (3, 4, or 6 TB) drives for parity and your other data drive, and just use your 2TB Black as a data drive.

 

r.e. the case => given your cost constraints, the Norco you noted is fine.

 

 

[thejammonster]

Thanks for the input.

 

Regarding the cache drives/pool, would 256GB be sufficient in size?  If I were to increase the data drive sizes to 3 or 4TB would 256GB cache still be sufficient?  I couldn't really find any recommendations for cache drive size based on the overall array size.  It seems like the cache size may be independent of the array based on application.  My use will be TV/movies/music for the most part, so I don't foresee any huge file size requirements.

 

For the drive sizes, I may consider larger drives if the WD Green series works fine for the parity drive.  It seemed logical to do it this way and utilize my existing parts, but I can also see the benefit of overbuilding my array and growing into it for a bit larger investment up front.  The last thing I want to do would be to underestimate my usage and run out of space right away.

 

Any input on needing an optical drive?  Would it even be recognized by the unRAID OS?

 

Anyone else with thoughts on a server chassis?  I still think the Norco case is my best bet but there may be someone with experience in the matter out there.

[tdallen]

If you use a cache drive to cache writes to the array it needs to be as large as the data you would write between runs of the mover application (typically daily).  A lot of us write directly to the array and just use the cache drive as an application drive, though.  256GB would be more than sufficient for an application drive and sufficient for most use cases where you are caching writes to the array.  You are correct, btw - sizing the cache is independent of the array size.

 

I like Red (NAS) drives for their longer warranty.  Your parity drive should be as large as, and as fast as, any other drive in the array.  For example, some people build arrays of green drives but use black for parity.  I just stick with WD Reds, though I'd consider HGST if I found a good deal.

 

The only reason I can think of that you might want an optical drive would be to pass it through to a VM - I've never found a reason to have an optical drive relative to using unRAID.

[thejammonster]

I read up on the differences between the WD Red and Green drives and there really doesn't seem to be much difference at all.  This site gave a good comparison.  I decided to go with WD Red drives, so thanks for that!  The extra year warranty and double life expectancy is certainly worth $5/TB.

 

All of my questions have been answered at this point.  I am still open to suggestions on a short-depth, rackmount case, but I'm not counting on a better solution.  Thanks to the 2 users in this thread who provided input.

[garycase]

Agree with using Reds => that's all I've used for well over 2 years.

 

As for the size of the cache drive -- as noted above, it really has nothing to do with the size of your array ... it simply needs to be large enough to cache a day's worth of writes and/or for any application storage you might want to use it for.