using ZFS on a stripe and copies=2 for a dataset

[disaster]

HI,
I'm experimenting with Nas4Free and ZFS, I have a system with 2 * 3 TB drives.
On these disks I'd like to store some files which are crucial to me, and some who are not. (Of course I'm going also to backup that data)
So I thought that I'd partition my disk with a mix of raid 1 an 0, so
2 TB each Raid 1 = 2 TB "safe"
1 TB each Raid 0 = 2 TB "not safe"

But from what I've understood partitioning the disks is not recommended on Nas4Free, so I went with a ZFS stripe pool on both disks and created a dataset with copies=2 where I'd store my crucial files.
So in case of a disk failure I won't lose anything that's on the 2 copies datases, I just have to purchase a new disk and scrub the pool, right? The files with copies=1 would be just lost.

Does this look like a crazy idea or could it be a good one?

Thanks!

[substr]

Sounds like it would work; but doesn't seem to.

I just tried it, and at the very least, it will require a trick to get the pool to mount with a non-redundant drive missing. Theoretically, the copies=2 files are still there. But if the pool won't mount, that isn't much help.

[kenZ71]

Keep it simple, go with a Raidz1 mirror. Two drives with the data replicated to both.

This provides safety if one fails, your data is still safe.

[disaster]

Uhm, I've read viewtopic.php?f=66&t=6235 and as I can't have ECC ram on my system I'll go with a mirrored UFS fs

[crowi]

Why not add a third drive and go for software RAID5 (not ZFS as you have no ECC RAM), so you have 6 TB useable and certain redundancy.
RAID on partitions is not the best way to go, keep it on drive level.

[disaster]

I'm using a quite old motherboard http://www.viaembedded.com/en/products/ ... 3.pdf.html that has only 2 SAS ports
I would need to add a pci SAS controller to go with 3 disks, but then I don't think I'd want that beast in my living room

[substr]

If you aren't using ZFS because you don't have ECC, then you probably wouldn't use software RAID5 either; it would potentially have the same risk of corrupted parity calculations.

[crowi]

No because Raid does no automatic repair also on reads like ZFS does.
On Raid you might get a corrupted file, on ZFS your whole pool can get silent corruption.
ZFS also has much higher RAM usage.