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Trying to spec out my dream server but am a bit stuck!

willsy2

Novice Member
i've just built a server with 5x500 Gb drives and i decided to go down the hardware raid route using an LSI Megaraid 8 port card bought at a reasonable cost on ebay. I'm running Naslite-HDD server which is very reliable and pretty cheap, but doesn't support hardware raid.
You said it wasn't mission critical, but re-ripping 5Tb + of movies would be a right chew if you had a problem.
If you still decide to go down the software route, you could get one of these which would add another 4 ports, but i'm not sure how linux would handle Raid 5 using onboard ports plus add-on ports.
 

willsy2

Novice Member
Yes the one i used was the PCI-X model, purely because i'm using a Pentium-M board which has a PCI-X slot.
The Supermicro seems a good price for an 8 port unit. It might be worth checking the Linux hardware compatability database to make sure it's supported.
I'm note sure about the ease of use of the software vs hardware for ease of maintenance, but you can expand hardware raid setups although i don't think it's straight forward. By the time i've outgrown my present storage i'll probably be thinking about building a new one.
I'd be ready for a few problems along the way and would test it pretty rigorously before committing a lot of data to it. I had quite a few hiccups with mine. I built it in November last year and only just switched over to it as the main server a couple of days ago.
 

willsy2

Novice Member
Personally i would run the OS on a smaller hard drive connected to one of the motherboard ports, and keep the raid volume on the add on card as data only. Then if you have any OS problems your data is kept separate.
 

cj

Active Member
Hi,

Case: SilverStone Temjin TJ05. This has space for 8 x 3.5 inch drives. Are there cases which can house more drives? If I wanted, say, 5 more drives, are there suitable external enclosures to “add-on” and connect to it, perhaps via eSATA?
I use one of these for my server: -

http://www.microplex.no/product.aspx?pid=PC343B

You can easily 28 drives in there, as well as a couple of PSUs. Really nice case and very easy to work in. The most SATA ports I've seen on a motherboard is 8 - you'll need to add a SATA card or two for more ports - I currently use a couple of these: -

http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=258223

That gives me a total of 24 ports. There are single cards with 24 ports on them, but they seem to cost upwards of £500.
 

limegreenzx

Banned
Ah, my mission critical comment was not very well explained. :blush: What I mean't was enterprise level servers tend to cost the earth and feature hot-swap and other redundant/fail-over stuff so as to minimise downtime. Obviously re-ripping everything would be a right pain but I wouldn't mind having a day or so "down-time" whilst I rebuilt the raid array. I read that software RAID tends to be easier than hardware RAID for "novices" to maintain. Is that so?

I would think about using both. Use hardware RAID to create your logical drives (what is presented to the OS) then use software to create your 5-10 terrabyte filesystem. Many filesystems allow you to increase your filesystem size and to load balance on the fly. This will give you alot more flexibility to increase you filesystem size over time. You could also use real software RAID 0 with hardware RAID 5, but this tends to be less flexible.
 

Paul_Maddocks

Novice Member
Having recently built a server form my home media requirements and my experience of RAID both at home and in the workplace is that no matter what, it will usually go wrong at least once! I have had to restore my array from backup once after a disk failure / replacement cause the whole RAID 5 array to fail (which its shouldn't, but it did and thats what you have to be prepared for!). A mate also had his RAID 6 array lose the plot recently (linux software raid) and he counts himself lucky he was able to get it back up and running (after much tweaking and the darkest areas of file system recovery!)

You need to think about how much data you will be putting on your server, and if you be upset if you ever lost all of it through some form of hardware / software issue. If you are remotely concenered about loosing it, you should also invest in a some form of cheap backup, this can be as simple as a few external HDDs to keep a copy of all the data. The bigger the array, the bigger your backup needs to grow to accomadate.

Bearing this in mind, you need to be careful about your raid level selection. I would say you should consider at least RAID 5 (so for 5TB you would need 6 x 1TB HDDs (always loose the capacity of 1 disk to parity). If you are more concerened, investigate RAID 6 which supports up to 2 disk failures in the array, for a 5TB array you would need 7 x 1TB HDDs).

Stacking software raid on top of lower level hardware raid is an enterprise type trick and I would say that using something like that at home, unless you are very concerned about data and not implementing a backup is overkill. You also have to bear in mind that this offers more levels of failure, as a raid array can fail at software level or hardware level and impact the data!

Definatly keep your OS on a different drive and your array for data only, not only will this help with installation, but its generally good practice.

Just a few things to think about. I used Silicon Image Si3114 PCI SATA raid cards in my server, they only support up to 4 drives per array but I brought 2, so when I need to expand, I build a new array with new disks on the second card and move the data over...

Good luck
 

cj

Active Member
Thanks cj, that's a serious case, isn't it. I looked on the Lian Li website when I was hunting for a good case but must have missed this one. Thanks.



Excellent, thanks.

It sounds like you've already done what I'm looking to do. :thumbsup:

So are you running a software RAID5 setup? Does that card allow your drives to spin down when idle? What OS are you using? Are you running your server headless? If so, do you have onboard graphics or a separate graphics card? Any idea what the power consumption of your rig is when idle? Is it nice and quiet when idle?

Sorry about all the questions (I've plenty more where they came from ;))
I'm actually running Windows Home Server in my setup, so no RAID backup, just the backup built into WHS. It has actually made my media server setup far, far simpler (I was running Windows Server 2003 before). With WHS you add all your drives to a storage pool, and just create public directories that share the storage. With 2003 I then had to share all the individual drives i.e. with 15 drives I would get 15 shares across the netork for all my media, and I had to point all my clients to 15 places. With WHS I get just 3 shares (Movies, Photos and Music) which will never change no matter how many drives I add. I also love the how easy it is to upgrade drives in WHS - just tell it remove a drive from the storage pool and it copies all the data off elsewhere.

I currently have 18 drives in there and it's consumes around 300w according to my power monitor (with a 327w peak). It's far from quiet (there's 10 fans in there), but not an issue for me as it lives in my office in the garden.
 

cj

Active Member
300watts is not bad assuming that is with all drives spinning and not simply the mobo and fans consuming all that power ;)

I did look at WHS but decided against it because it only offered pseudo RAID 1. To backup all my movies would require double the diskspace obviously and with disks approaching £200 a go I couldn't afford to do that :rolleyes: I know that RAID5 is not a proper backup but I figured it'd be a bit give me a bit more protection than having nothing at all. I've always got the original DVDs to fall back on if everything goes pear shaped and I have to start again from scratch. :)
I'm fairly sure you can still use a hardware RAID with WHS, it's just not recommended. For me the benefits of the shared storage far outweighed any RAID capabilities - just having a couple of shared directories rather than well over 20 has made life a lot simpler in my network. I just keep photos and documents backed up, as like you I've always got the optical to fall back on. Anyway, good luck and keep us posted :)
 

HMHB

Distinguished Member
I still can't see the point of having RAID for storing DVDs and music to be honest as you'll need to back it up as well anyway :confused:
 

limegreenzx

Banned
I still can't see the point of having RAID for storing DVDs and music to be honest as you'll need to back it up as well anyway :confused:
One of the other benefits is speed. More spindles will read a lot quicker than a single spindle. RAID controllers can have very large cache sizes to further increase read and write speeds.

If you are streaming to a number of devices this could avoid a major bottleneck.

Also, if you look at where the term RAID came from (redundant array of inexpensive disks),and even if this is less of a issue these days compared to the late 80's, 2 X 500GB disks are still a lot less than 1 X 1TB disk.
 

Paul_Maddocks

Novice Member
The idea of using RAID is perfectly sound. Most people use implementations of RAID these days to get 1 larger volume out of a number of disks, so if you want 5TB of space, you can't buy a 5TB HDD for example. (well, not yet!)

RAID 5 redundancy will give you protection against a single disk failure in the array. Worth remembering that the more disks you have, the higher the chance of one failing so any more than 5 drives and I would consider RAID 6! You could also negate this by using an online-spare but if you go that route, RAID 6 achieves the same. The theory is that you replace a drive, start the rebuild and bobs your uncle, however, should you have a double disk failure, or some form of issue with the rebuild you may loose the lot! Doesn't happen all that often (once to me in 8 years in IT) but it does happen and especially on lower cost solutions such as sofware raid or cheap hardware raid cards!

Regarding backups, you are correct that you need ideally the same again in some form to store all the data. I would not be too concerned about generations and versioning as the data is only really likely to be added to over the life of the server so you would only really need 1 'backup set'. If you were backing up documents that were constantly changing and you needed to roll back to a previous version, backup generations may be more important. I would say not for 5TB of media though... unless you are worried about external disaster (fire / flood etc) then I would not worry too much about offsiting the backups. Really its just to protect against array corruption.
 

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