Help on next freenas setup

[krantz]

Hello,

I´ve been on freenas since jun 2013, successfully created my NAS with 6 disks; the server is a U2 server monster I bought on ebay, with 32 gb ram (mirrored to 16 gb ECC).

My disks are
4 x 3TB
2 x 1TB

My setup is a volume with 3 mirrors (2 mirrors of 3tb each, 1 mirror of 1tb)

Recently one of the disks from mirror 2 started getting hiccups (CAM errors and things like that).... and then the other disk of mirror 2 started doing the same.

I inmediately replaced the failing disk, finished resilvering after like 50 hours, and BOOM the other disk died.

So now I bought another disk to replace the second failing.

But I am wondering if my setup is correct -- right now I think my data is safe, however I would like to know if you guys see any better / safer setup?

BTW the data usage is around 4 tb, and most of that is already obsolete / deprecated; the most valuable things are the timemachine backups for 2 computers, and personal photos and videos.

Thanks for any input / guidance you guys can provide.

 

[gpsguy]

Given the way you use FreeNAS, you might consider backing up the data, rebuilding it with 6 disks in RAIDz2, and restoring your data. I'd dump the 1TB drives and replace them with 3TB drives. This would give you ~10TB of storage. It gives you a bit more redundancy than what you already have.
The flip side, is that you'll loose a bit of performance and ease of growing your pool.

Or, assuming you could squeeze 3 more drives in your chassis, you could add 3 more disks and create three way mirrors. There's a lot of overhead, but it would provide additional redundancy to what you already have. For some use cases, like iSCSI in a business/enterprise environment, this makes sense. Again, for your use case, I'd recommend going with a RAIDz2 pool.

 

[krantz]

Thanks for your reply, Gpsguy.

1) Dumping the 1tb drives and repace 2 additional 3tb is gonna be a little expensive for me at the moment.
2) I cannot squeeze any more drives inside the server. It´s a U2 rackable, very limited space -- and from my personal experience, having external drives via USB is not the best course of action.
3) Can I setup the Raidz2 with the drives I have right now (4x3tb, 2x1tb)?

 

[gpsguy]

1) Okay

2) You are correct. Do not use USB connected hard disks for your storage.

3) Technically you could, but the problem is that your volume size will be based on the size of the smallest disks. So, with the 1TB drives in the mix, your volume size will be about ~3.5TB. And, since you shouldn't use more than 80% of that, you should limit your usage to 2.8TB or less. You already have 4TB in use.

Now, you did say that most of the data is "obsolete / deprecated", so if you were able to reduce your storage needs to live within boundary above, you could reuse your current drives. There is a way to grow RAIDzX storage, by following a process to slowly replace the existing drives. So, if you did go this route and bought two more 3TB drives down the road, your storage would automatically increase, without having to start over.

In any event, if you want to move to RAIDz2, you would need to backup your data, delete your current volume, and start afresh with RAIDz2.

 

[krantz]

Thanks a lot for your valuable input.