Unraid or SnapRaid not sure which one to go with

[ashman]

I currently have a 1200 series Areca 16 port raid controller to which 16 drives are connected in two RAID 5 volumes, I am using this for media backups for two NAS's. I have been looking at Unraid and Snapraid and think I would like to try one of these, just not sure which. Unraid costs about $100 for the number of drives I have and seems pretty simple to setup booting from a flash drive. SnapRaid while free, seems more difficult to setup but has some nice features that Unraid does not. I am a little confused about SnapRaid as it seems like a backup only solution, not something I could configure and start copying files and folders to, am I wrong? What do you guys recommend?

 

[saiyan]

If you need real-time RAID which always updates parity data when data are changed, then you are better off using your existing Areca or other hardware RAID controllers. And if you already have Areca, don't even bother with unRaid.

If the data you want to protect consists of mostly media files which don't change very often, then SnapRAID could be a good choice if you don't need real-time RAID protection.

Also SnapRaid does not require special RAID set or volumes created. You basically use disk volumes formatted in NTFS (Windows) or EXT4 (Linux).

SnapRaid basically consists of a small executable and require just a simple configuration file. There is no special registry setting nor does it install anything to run in the background. You can stop using SnapRaid anytime you want.

Once you have a appropriate SnapRaid configuration file setup, you just need to run the snapraid console command to sync parity data, check for difference, scrub data or fix data.

For Examples..
To sync parity data, you run the following command and option:
snapraid sync

To check for changes in data to see if you need to sync:
snapraid diff

To scrub data:
snapraid scrub

To check whole array data:
snapraid check

To fix data:
snapraid fix

The fix command allows additional filtering options if you only want to "restore" or fix certain files or directories.

And don't even bother with any GUI frontend for SnapRaid. Just get comfortable running the SnapRaid command in a console window.

If you have never used SnapRaid, you probably won't be able to imagine what the system is like and how you would maintain or update array data.

I would suggest you create a virtual machine, install your preferred Windows or Linux system and create multiple virtual hard drives to test SnapRaid so you can see how SnapRaid sync and restore files.

If you plan on using SnapRaid on a PC running 24/7, you can even setup a cron job or windows scheduled task to run a snapraid sync at night.

When I upgrade by media PC an year ago, I chose to use SnapRAID (plus StableBit DrivePool) primarily because I need to expand my old RAID-6 volume hosted by ARC-1880i. I would have to backup my data, replace hard drives with new ones, recreate new RAID set and then restore data back. (Or I could replace one hard drive at a time and go through RAID rebuild process).

I thought if I need to go through all these backup and restore routines every time I need to expand my RAID storage capacity, I may as well start using SnapRaid which allows me to replace one hard drive at a time. Also SnapRaid advertised that it uses block-level checksum so it can detect and fix silent errors (aka bitrot).

For data or volumes which changes very often such as your OS drive, I would use to tradition RAID-1.

And don't forget to make monthly backup of your data to external hard drives and store them off site.
For me, my off site storage is my car (parked on the street) so in case my apartment burned down I will still have some recent backup..

 

[ashman]

Thanks for all that info, its very helpful.

 

[Dangman]

You might also want to read this article about btrfs and ZFS:
http://arstechnica.com/information-...-and-atomic-cows-inside-next-gen-filesystems/