Server Advice...Please!

[Drobbins]

Hey Everyone,

I am planning to build a storage server over the next year or so, i want it rack mountable with hot swappable hard drives and approx 2TB of usable space in a raid i think it is Raid 5 i want.

I have dropped out of the PC market for a long time and am unsure what is good and what is not.

I am using Apple Mac's on my network and am thinking of using FreeNAS as the operating system on the server.

I thank you for you ideas
Richard

[Moby-Dick]

freenas works well - spend the money on a good raid controller - 3 1TB drives in Raid 5 will do you nicely.

[Drobbins]

What are the key elements to look at when looking or a Raid Controller? Are their any recommendations?

3 1TB Drives in Raid 5 is what i was thinking. Would processor power be required or is it more memory or is it more to do with the speed and durability of the disks.

I am going to read up on FreeNAS and see what that is all about but it seems the OS of choice for this project.

Rich

[arthurleung]

Since a good RAID controller cost quite a lot, perhaps get 4x1TB in RAID1 (Two RAID1 or 1 RAID10) instead? I find that there is not much reason going for hardware RAID for 3 drives or below.

Note that most hardware RAID controllers support Mac so you can just use one of your old Mac (if any) instead of building a new PC.

A decent, non 2nd hand hardware RAID controller from Adaptec/Areca/3Ware/LSI will cost 200+ (Usually 4 ports). You might be able to get some cheap 2nd hand card between 70-250 (Usually 8 ports) on ebay.

[Drobbins]

What kind of specification machine should i go for? I wasnt 100% on a raid i was just looking at that option from a backup point of view as that was the point of me building the server to begin with.

Rich

[GaryRW]

at the risk of going back to basics (or being pedantic ), RAID isn't back up.

You can use a raid array to back up data you have elsewhere, but the point of RAID (well, except RAID 0) is to prevent you losing data when a drive goes bang. I'm not saying having the drives in RAID isn't a good idea, just that it's only one part of the picture. You should still back up the data on the RAID array to a completely different system.

Otherwise if something happens to the entire array in one go (power supply blows up and takes the drives with it, sure others could come up with appropriate disaster stories...), it doesn't really matter if the screwed up data is spread over >1 drive.

apologies if the above was obvious!

[Steve]

Otherwise if something happens to the entire array in one go (power supply blows up and takes the drives with it, sure others could come up with appropriate disaster stories...), it doesn't really matter if the screwed up data is spread over >1 drive.

Also, software could delete/modify stuff it shouldn't, in which case your data is toast... and the RAID array will quite happily, fault tolerantly, turn it all to toast for you.

RAID limits downtime, but in most cases not data loss.

[Drobbins]

I understand that RAID isnt the bee all and end all of data security on a file server and that i should have a completely different array of drives for backup, what do you suggest? If i think like this i could have a server to back up the server to back up the server (etc).

Rich

[i4000]

If you go software RAID, don't forget to factor in the performance impact:

RAID 1 will slow down your writes to 50% of the speed of your slowest drive (i.e. you have to write everything twice)
RAID 5 will slow writes down even more, in a 3 disk setup effectively every write operation results in 4 individual operations - 2 writes for data, 1 read and a final write for parity (Check out this article for a more accurate description http://www.storagereview.com/guide20...ReadWrite.html)

If you're even slightly concerned about write performance on the array then I would go for proper hardware RAID where the full RAID overhead is offloaded onto a dedicated RAID controller. If your budget stretches I would also go for a card with a write cache (preferably battery backed)

If you are just going to use the array as a large data repository where you write things once and then read many times (media server etc.) then the write performance won't be such a big concern for you.