Need help building file server with large capacity
 

Please answer each question :)

- I need 20TB file server that will be running Samba. This company have about 30 workstations that will be using it.

- My question is what CPU and how much memory should be enough for this?

- If I use 5x 4TB hard drives what RAID system should I use so that Linux sees 20TB space?

- Is it better to do it this way or to mount and share each drive separately?

Any CPU will do, 30 users is not much.
Any amount of RAM will do, although more RAM will give you more cache.
To sum it up, an Atom with 1 GB of RAM will do the job.
As for 20 TB volume I'd use Btrfs. Although ZFS is an option, too (may need more RAM for that). In conservative side is mdraid.
You will not get redundancy with five 4 TB drives for 20 TB volume, so make sure there is a reliable backup solution.

Had a problems with btrfs + samba.
My vote is for ZFS. It will replace mdraid layer also. And it will help you with backup too.

Agreed with Emerson re: CPU/RAM


" - If I use 5x 4TB hard drives what RAID system should I use so that Linux sees 20TB space?"

You would be using RAID 0 (stripe) to see 20 TB of space. Which also means no redundancy.

If you want the best redundancy you would want a RAID 6 which gives you 3 drives usable space (12 TB).

You really don't need anything special on the technical side since you really don't have many users, just a lot of space. Once you present your storage to your system, I would partition them down to smaller filesystems (500g to 1tb) for better manageability

I've still always liked ext3 :D

from what i have read ZFS will NEED a lot of ram

something like 8 gig for a 4 TB drive install
so for a 20 TB server ... a lot of ram

Go with zfs. btrfs is not yet ready for prime time. Conversely, zfs is well tested and seen large enterprise use for some years now. ZFS will USE a lot of ram, if you have it, to increase efficiency. A few hundred dollars worth of extra ram is nothing for a company with 30 employees. If you're worried about maxing performance, budget a couple extra ssd's for zil and cache. Here's some benchmarks for various configs:

https://docs.google.com/a/apps.every...rive_web#gid=1

Peace :cool:

You may also want to consider an Illumos base distribution for this project such as OmniOS or Nexenta Community Edition:

http://omnios.omniti.com/


http://nexenta.org/corp/downloads/do...munity-edition

I'd lean towards OmniOS.

Peace :cool:

P.S.; But perhaps best option may well be FreeNAS

http://www.freenas.org/

All of the above advice ie any kind of meaningful RAID means losing usable disk space & (also) have a look at zfs.
NB: repeat after me 'RAID is NOT a backup ...'
(as above, RAID0 is just striping; one dead disk = ALL data lost)

@byau: ext3 was good, but we're all on ext4 now :)

Generally more RAM is better, but if its mostly just a file server and most processing etc is done on the wkstns, then the server won't need as much grunt/RAM ....

HTH

PS:
https://en.wikipedia.org/wiki/Standard_RAID_levels
https://en.wikipedia.org/wiki/RAID
http://zfsonlinux.org/