first time build of unraid server - comments re. components etc. needed

[lars]

ok, due to a constantly growing media library (mainly music, but movies as well) existing at this point on 5 x 3tb wd ext. usb-hdd and my constant fear of data loss i am going to build my first unraid server. after longish research for options - it seems to be the most cost-effective solution.

mow, living in jamaica - meaning i need to ship everything in, pay heavy duties and taxes etc. and can't just easily send it back for exchange if stuff is incompatible, i need some opinions on my concept so far!

 

the idea is to use as much as poss stuff i have here already, but don't skimp to much on parts that make sense (keep in mind - whatever the cost in the US - it cost me nearly double when i finally get it here)

 

to start with:

 

i have an old HP ProLiant ML350 (rack (5U)) server sitting here, collecting dust. i thought i would gut that one for housing and maybe psu (it has 2 redundant 500W psu's). case is a given, psu(s) i still try to figure out the future usability (it would be nice, but...)

 

- as for the mb + cpu, my thought is Gigabyte GA-970A-D3 mb + Athlon II X2 260

- ram: 2 x 2gb kingston ddr3-1333 (have them sitting here already)

- initially there will be 5 x 3tb wd-green hdd for data, 1 seagate 3tb for parity (all existing here already). due to financial restraints the hot-swap cages are a big maybe at this point/ can follow later. the case has plenty of room for the drives at this point.

 

now we come to my first question, beside your pro's/ con's about the above. the cache drive!

depending whom i talk to it goes from: yes! its a must have... to: dont really need it... 

so, since i am new to unraid, cache yes or no? what are the advantages in daily operation? should it really be as big as your drives (why??? doesnt make sense to me) or rather a smaller but fast drive (have a old seagate raptor 500gb laying around here). as far as my logic goes, it is a cache - so a fast hdd should beat a large hdd for that.

 

next question, i am not to clear about at this point: 3tb drives are supported now by the latest ur5rc, right? is sata 3 supported as well? i know, it will never use the possible speeds - its more about potential issues while running the server. most of the drives i have are sata 3 and considering the nearly non-existing price difference, i would keep that going for future advantages.

 

what are your thoughts about that setup sofar, any input would be welcome!

 

L

 

 

 

 

[BobPhoenix]

I use a cache drive on one of my unRAID servers but not on the other two also I have almost zero plugins installed.  I do not use a cache drive on two of my servers because I almost never write to them and when I do it is to a specific drive - so they would not benefit from a cache drive at all.  The one server that has a cache drive is one I write to several times a day - it is my backup server.  That one works well with a cache drive.  So long story short.  Look at your expected usage patterns. 

 

I use the following to determine when I want a cache drive:

• A cache drive isn't needed (as a cache drive) if you almost never write to your array.
  
• It is advantageous if you write to the array often and want a faster write.
  
• You can use the cache drive as a hot spare as long as it is the same size as or larger than the drive you want to replace and it is the same size as or smaller than your parity drive
  
• You can use the cache drive as an application/data drive for plugins if they need to write often or require lots of space and you want faster access than your array.
  

 

[trurl]

The idea of having the cache as large as your other drives I think is just so it can be converted into an array drive if one of them fails.

 

I have a 150GB Raptor I am using as cache and all the drives in the array are 2 or 3TB, so I am not doing it that way. If I have a failure NewEgg or Amazon is only a couple of days away. Your case may be different.

 

I am only caching shares that get written a lot. This is mostly torrents and usenet downloads.

 

Another great use of the cache drive is for running plugins and other apps. The cache disk is ready before the array comes online so it can be used while things are still starting. If you look at some of the plugin threads you will see many people have configured a "cache-only" apps share and people without a cache drive have had to do some workarounds in some cases.

 

[lars]

i see, i guess that clarifies it. thx for the info!