Hey all,

 

Been lurking the forums now for a few days, absorbing as much info as I can (and probably missing twice that much), and I gotta say that this place is a wealth of information.  To that end, I'm strongly considering building myself an Unraid server, as it will fill 3 needs for me... spending money, geeking out, and more storage.

 

See, I'm getting married in less than 2 weeks, and lately every extra dime has been going to the wedding fund.  In that time, I've watched my little DNS-323 start to lose the battle with storage (not to mention it's terrible network performance).  So I've decided (don't tell the wife) that once the wedding is done, I'm treating myself to a new server.  My initial plan was to build a single server that would be a storage/Sagetv/torrent box/home automation server using either VMWare or possible just running off the host OS.  However, the main issue with that (for me) was the lack of upgradeability (I just made that word up) with a traditional raid array.  Enter Google and stumbling across unraid.

 

My thinking now is to move the storage off the "everything" server and have 2 dedicated servers.  With the right components, I should be able to make the unraid box low power, and also reduce the power consumption of the other server.  To that end, I've pieced together the following hardware... any thoughts/critique's/pointers would be more than welcome.  Thanks in advance!

 

Parity Drive = Western Digital Black 1.5 TB

Drive Cages = Icey Dock 5 in 3 x3

PSU = Antec Neo Eco 520

Ram = Geil 2GB Single Channel

Mobo = Intel BOXDH55TC

Sata Raid Card = Highpoint Rocketraid 620 (for mirroring of the cache drive)

Storage Drives = Western Digital Green 1.5 TB x3

CPU = Intel i3 530

Sata Card = Supermicro AOC-SASLP-MV8

Cables for Sata Card = Multi Lane Internal SFF-8087 to 4X Serial ATA Breakout Cable 0.5M x2 (Is this the right cable?)

Cache Drive(s) = Western Digital Black 640 GB

Case = Coolermaster Centurion 590

 

I think this covers everything.  I'd like to do my cache drives as a raid 1 array.  My understanding from reading the forums is that it will have to be hardware level, so that unraid will see it as a single drive (and not the drives separately).  I've tried to find out if the above controller is supported and if it does hardware level raid, but I have been unsuccessful so far.  Any help would be appreciated.

 

Cheers.

 

You might consider dropping the cache drive altogether.  The cache drive was a nice feature when unRAID write performance was in the 10-12 MB/sec range.  It allowed you to write the data quickly, and allowed unRAID to move the cached data to the array overnight when the ower wasn't impatiently waiting for it to finish.

 

But now direct write performance to unRAID is closer to 35 MB/sec, just a tad slower than a cache drive.  And writing to the array means that the data is immediately protected (without needing a RAID-1 cache disk).  Many users are abandoning the cache disk and using the precious SATA port for another array disk.

Ram = Geil 2GB Single Channel

Mobo = Intel BOXDH55TC

CPU = Intel i3 530

 

You may have seen my posts - these are the components I used to build my system a couple of months ago, although I have two 2GB Geil sticks for dual channel.  I can heartily endorse this configuration - it has been running very reliably.

 

As for the cache drive, it has boosted my write speeds from around 25 to 50MB/sec, but for my useage, protecting the data on the cache is not a high priority.  The cache can be enabled/disabled per user share.

Cache drive can be useful for other things as well, my sabnzbd and sickbeard installations live there.

Wasn't there a post somewhere saying that a Rocket Raid card would not work?

You might consider dropping the cache drive altogether.  The cache drive was a nice feature when unRAID write performance was in the 10-12 MB/sec range.  It allowed you to write the data quickly, and allowed unRAID to move the cached data to the array overnight when the ower wasn't impatiently waiting for it to finish.

 

But now direct write performance to unRAID is closer to 35 MB/sec, just a tad slower than a cache drive.  And writing to the array means that the data is immediately protected (without needing a RAID-1 cache disk).  Many users are abandoning the cache disk and using the precious SATA port for another array disk.

 

Yep, ditch the cache disk, spend the money on 4-8 GB of RAM and use the extra RAM as a makeshift RAM cache by adjusting the VM.dirty_ratio.

Wasn't there a post somewhere saying that a Rocket Raid card would not work?

 

http://lime-technology.com/forum/index.php?topic=3896.0

Wasn't there a post somewhere saying that a Rocket Raid card would not work?

 

There's a few posts talking about different model of RocketRaid cards. I haven't sorted through them yet.

 

This one seems scary -- http://lime-technology.com/forum/index.php?topic=3381.0 as it talks about

 

Feb 28 03:02:14 unraid kernel: sata_mv: Highpoint RocketRAID BIOS CORRUPTS DATA on all attached drives, regardless of if/how they are configured. BEWARE!

Feb 28 03:02:14 unraid kernel: sata_mv: For data safety, do not use sectors 8-9 on "Legacy" drives, and avoid the final two gigabytes on all RocketRAID BIOS initialized drives.

 

RocketRaid 2640 is not supported -- http://lime-technology.com/forum/index.php?topic=7540.msg72961#msg72961

 

On the forums, I found this gem -->

 

Without a cache drive

unRAID 4.5.3 - average 20-30 MB/s, peak reported 40 MB/s*

 

With a cache drive

unRAID 4.5.3 - average 50-60 MB/s, peak reported 73 MB/s*

 

So generally speaking, a server with a cache drive has write speeds 2-3x faster than the same server without a cache drive.

 

From this thread.  I read the release notes from 4.5.3 to the current and I don't see anything that would have made a cache drive irrelevant.  Did I miss something?

 

 

 

If the above raid card won't work, any suggestions for a 2-port raid card that is compatible with unraid and will let me do raid-1?  Thanks!

...My initial plan was to build a single server that would be a storage/Sagetv/torrent box/home automation server using either VMWare or possible just running off the host OS.  However, the main issue with that (for me) was the lack of upgradeability (I just made that word up) with a traditional raid array.  Enter Google and stumbling across unraid.

 

My thinking now is to move the storage off the "everything" server and have 2 dedicated servers...

 

Keeping storage separate from the media acquisition (torrent/rip) and display (sagetv) is a good idea, it simplifies life and allows you to use a really big, ugly case for your storage needs (and with the ease of adding extra drives to an unRAID array you'll find your array keeps growing).

 

As for SageTV, I use that on my HTPC and I have one of their HD Theater 200 media extenders and both play media stored on my unRAID array quite well.

 

Regards,

 

Stephen

 

So after more poking around, I'm thinking that despite the higher cost, this will be a better option.

Why not just get a Supermicro SASLP card?  It gives you 8 ports so will allow you to expand at a later date.

 

*edit* I see now its for mirroring the cache drive?  Why would you want to mirror the cache drive?  Its the least important drive in the whole system.

With a mirrored cache drive, I've significantly reduced the chances of data loss.

With a mirrored cache drive, I've significantly reduced the chances of data loss.

Unless you specifically need the added performance, writing to the array at 50 MB/s vs. 30 to 40 Mb/s, then not using ANY cache drive significantly reduces the chances of data loss too.

 

The "cache" drive was added to unRAID when its write speed was in the 8 to 10 MB/s range.  That was too slow for some who were recording HDTV .ts streams.  Today performance with no cache drive is sufficient for most users.

 

Joe L.

With a mirrored cache drive, I've significantly reduced the chances of data loss.

 

You are planning to spend $350CAD (plus 12-15% tax) to protect from some theoretical data loss.

After the initial data transfer (which your mirrored HDs wont help much) and can be done in a few days how much data do you think you will move daily.

Are you running a small business that will generate huge data daily and must be protected or this is to transfer your bluray backups or whatever you could download for a single day. The second case is not a very valid "data loss" IMHO.

25 GB without cash drive but with use of Teracopy will finish in less than 30 min (and you can watch an episode of something from the server in that time)

 

You know, it is after all your money and you can do whatever you want or feel justified but in your place this is what I will do with the extra cash you are planning to spend on perceived "data loss" protection.

1. I will up the parity disk to 2 TB and will change the brand to Hitachi (same price as your 1.5TB WD Black). You know, Google runs on Hitachi's.

2. Up the three 1.5GB data drives to 2TB and if you want that little bit of a speed advantage keep them Hitachi too or pick other 7200 rpm model - reasons are you are using CM590 as a case and that will limit your expandability to 13 data drives only and you need to value the slots you have. However the Hitachi and any other 7200rpm drives will run hotter and I am not sure in the cooling ability of these 5in3 you picked. Perhaps someone can share their temperature readings here.

3. You can use any HD you currently have as a cache drive or you can splurge and buy another Hitachi to be used as a cash drive (advantage will be ready use as a "warm' spare")

4. I will double the memory to 4 GB.

 

5. If you still want to splurge I will drop the CM590 and the 5in3 and go for a Norco 4224 (just wait for a sale) - go big or go bold. Then you will have to reconsider the MB as you will need one with at least two PCIe x16 slots (to be exact two PCIe  x4)

 

And if you are in the GTA I would like to buy your unused CM590 4in3 unit (cheap  )

I also have brand new and unused Biostar TH55B HD for sale cheap (I picked this as a bundle but then bought a better MB) and have no use for this one.

Mirroring your cache drive does not provide any real additional protection.

 

you would do better to just buy a hot-standby drive.... the size of the parity drive, pre-clear it to test it's reliability, and have it ready to go in the event of any drive failure.  If a drive fils, then you can immediately replace it, so the window for a second drive failure happening before the first is replaced is greatly reduced.

Actually, upon further investigation, it looks like this script that JoeL posted should minimize the amount of time that data sits on the cache drive.

I'm a big supporter of using a cache drive even if you don't need the speed benefits.  The way I see it, having a precleared warm spare handy is the best way to help you prevent data loss.  Also, just because you have a cache drive installed doesn't mean that you actually have to use it as one.  Every user share does not use the cache drive by default, you have to turn it on for each one.  So if you leave unRAID on it's default settings, your cache drive will never be used, but it will be ready to sub in for a dead drive at a moment's notice.

 

While a cache drive does effectively double the write speed of an unRAID array, I agree with the others that you most likely don't need that extra speed.  If you do choose to use the cache drive, you can edit the mover script to run every hour, every minute, or however often you like (Joe L.'s script is great too).  You can also manually kick off the mover script by pressing the 'move now' button on the shares page.  So your data is only unprotected for a few minutes to a few hours.  In my case, my data is always coming from my desktop, so it is no more 'at risk' on the cache drive than it is on my desktop's internal drives.

 

Furthermore, I only enable the cache drive for shares that contain less important data (TV, movies, etc).  My critical shares (Backup, Pictures) don't use the cache drive at all.

 

I agree with the others that there's no real benefit to mirroring the cache drive.

Thank you for all the tips guys, much appreciated.  After taking all of your advice under consideration, I think I've decided on the following -->

 

Case = Coolermaster Centurion 590

CPU = Intel i3 530

Mobo = Supermicro MBD-X8SIL-F-O

Ram = Kingston 2GB ECC un-buffered (Should I try for 2x 1GB for dual channel?)

PSU = Coolermaster GX 650

Sata Card = Supermicro AOC-SASLP-MV8 (Possibly x2 for future use)

Sata Cables = 3WARE Multi Lane Internal SFF-8087 to 4XSata x2 (Are these the right cables?)

Drive Bay = Supermicro Black 3X5.25 to 5X3.5IN SATA Drive Bay x3

Cache Drive = Western Digital Caviar Black 2TB

Parity Drive = Western Digital Caviar Black 2TB

Data Drive = Western Digital Caviar Green 2TB x2

Looks pretty good, not sure I'd bother with the black drives though.

 

Also you might want to consider upgrading that i3 530 to an x3430, you are using a server class motherboard with server class memory, but you wont be able to use the ECC capabilities of the memory with an i3.

 

Also the x3430 is a quad core but doesn't have hyperthreading whereas the x3440 has hyperthreading, not sure what difference it makes in the real world though.

 

That looks like the right cable.

 

How are you going to put the drives in the case?  You might want to consider something like the Lian Li x34B hotswap cages, if you do go with those you will need cables with right angle connectors on (actually you would want left angle, but I'm not sure thats even a real word).  Something to think about though.

 

Looks like a good single rail PSU, shouldn't have any problem putting 20+ green HD's on that.

 

How many HD's do you want to be able to go up to? 9 bays might end up being a bit restrictive, but will be fine to start off with.

I have no need for a server grade chip (plus I don't want spend an extra $100 for a Xeon).  In reality I have no need for a server grade motherboard, but that one I listed had everything I was looking for (plus I wanted to try out the remote management).  Also, I like choice of expansion slots and that it uses Intel NICs.

 

Unfortunately, with this motherboard, you're forced into using ECC ram, but it's a necessary evil.

Ram = Kingston 2GB ECC un-buffered (Should I try for 2x 1GB for dual channel?)

 

Make sure that this memory is on the Supermicro AVL or at least you can visually inspect it to see if the memory chips used are x8.

I don't think dual channel will make much difference with unraid, so you are better going for a single 2GB, leaves you with an easier expansion route in the future

I don't think dual channel will make much difference with unraid, so you are better going for a single 2GB, leaves you with an easier expansion route in the future

 

That has always been my philosophy, and I still endorse it.  However, dual channel RAM can come into play if you set unRAID to use the RAM like a cache disk, thereby getting somewhat faster writes to the array.