NAS/SAN/iSCSI

[Wrench00]

Any other recommandation besides FreeNAS to make a homebrew data storage device.


What are some good commercial software for a Data storage device.

 

[Dangman]

Amahi with Greyhole:
Links:
http://wiki.amahi.org/index.php/Greyhole
http://code.google.com/p/greyhole/
http://www.amahi.org/

Pros:
+ Lets you use different size drives and combine them into one drive pool ala WHS's Drive Extender feature.
+ Can set the number of copies of a folder/file that you want stored on other drives. So unlike WHS where only a single copy of that data is stored on a different drive, you set it to where that file/folder can be copied across every single hard drive in your PC. So 5 drives means 5 copies of your data
+ Supposedly you're still able to remove a drive from that Greyhole server and still be able to read the files on another PC without greyhole installed.
+ Free and works with Linux, which is also free

Cons:
- Still very new and experimental. So not all of the bugs may have been fixed or discovered yet.
- GUI is still relatively clunky
- Takes extensive amount of time to recover and repool data across a new drive after a drive failure
- Amahi has a tendency to try to become the default DHCP and DNS cache server for the entire network
- Uses the old “landing drive” system of the older iteration of WHS

Notes:
* Should you delete a file while using Greyhole, all the other copies are deleted as well.
* While the above example recommend Amahi Home Server, you can use Greyhole in virtually any Linux based OS

Flexraid Basic:
Links:
http://en.wikipedia.org/wiki/FlexRAID
http://www.openegg.org/

Pros:
+ Uses data based parity in which parity data is only kept of the file actually stored, not like with traditional RAID where parity data is is kept of the entire hard drives, regardless of whether or not you have data on those drives.
+ Allows use of different sized drives as a result of the data based parity setup
+ Free
+ Can be used with either Linux or Windows.

Cons:
- Not realtime parity so if the data needs to be protected at all times, not a good idea to use FlexRAID
- The FlexRAID needs periods of time of no usage at all in order to re-sync the RAID
- If multiple users are editing stored files, flexRAID is not recommended

Notes:
* FlexRAID Live does not have the cons of the FlexRAID Base. However it has not been released yet and even it is, it would still be a bit experimental at that stage.
* A little old but still good reading:
http://www.overclock.net/htpc/694948-has-anyone-tried-flexraid-their-media.html

Unraid:
Links
http://www.lime-technology.com/
http://lime-technology.com/wiki/index.php?title=UnRAID_Wiki[/QUOTE]

Pros:
+ Allows use of different sized drives.
+ Should one or multiple drives die, only the data on those dead drives are lost.
+ If the data on the hard drive isn’t being accessed, the hard drive is spun down until needed.

Cons:
- unRAID Free has a limit of 3 drives (2 data, 1 parity).
- unRAID Plus has a limit of 7 drives (5 data, 1 parity, 1 cache)
- unRAID Pro has a limit of 21 drives (19 data, 1 parity, 1 cache)
- Costs $120 for unRAID Pro (21 drives) and $69 for unRAID Plus (7 drives)
- Relatively low write speeds without that cache drive.

Notes:
* “unRAID™ is similar to RAID-4 in that for every n hard drives, there are n-1 data drives, and a single fixed parity drive” - From unRAID website

ZFS File Server:
Links:
ZFSguru NAS fileserver project
napp-it ZFS server appliance
Building your own ZFS fileserver

Pros:
+ Free
+ Fairly resilient against crashes, corruption, and such due to the copy-on-write feature as well as the snapshots feature.
+ Maintenance free in that the file system will periodically check and fix itself
+ Very flexible in terms of hardware and software changes.
+ Supports encryption of data

Cons:
- May be difficult to learn for a person who've never worked with BSD before
- Requires a large amount of RAM (4GB+ recommended)
- Cannot expand an existing RAID array with additional drives.

Notes:
* ZFS uses a different method of storage expansion:

What you cannot do, is expand an existing RAID-Z (RAID5) or RAID-Z2 (RAID6) array with one or more disks.
But, you can add new disks or RAIDs to an existing pool. So if you have a 4-disk RAID-Z, you can add another 4-disk RAID-Z so you have 8 disks. The second array would share free space with the first; in essence it would be a RAID0 of two RAID5 arrays. ZFS can expand this way.

What you can do, is expanding mirrors and RAID0's. In the example above that's what actually happened: a new array is RAID0-ed with the existing array. New created files will be written to both devices, for additional speed. Setting copies=2 would make files in that directory be stored on both RAID arrays; for extra redundancy.

* Here’s another thread filled with tips and an excellent hardware list for a large sized ZFS server:
http://hardforum.com/showthread.php?t=1572188

 

[Wrench00]

Awsome thanks.