Is this possible with ZFS?

[stevoblevo]

I have 4-5 hard disks, all different sizes and brands and all that.
a 2TB drive, another 2TB drive, 1TB drive, 1.5TB drive

When I put them all in one stripe zfs volume what happens? I don't lose any capacity correct? Yet, if just 1 drive fails I lose all data in the whole volume? Even if it's only a few GBs one drive fails and I lose it all even though the other drives are good? It's also impossible to remove a drive from the volume without upsetting all the data correct?

What my question is: Is it possible to have all these drives pooled together without losing capacity but also only losing the data of one drive when one drive fails? I understand it wouldn't have the same performance as a striped volume. Also, for important files/folders is it possible to have it setup where they can be located on two drives as to survive one drive failing?

If I remember correctly Windows "Vail" would do this sort of thing with Drive Extender: http://en.wikipedia.org/wiki/Windows_Home_Server#Drive_Extender
I was just wondering if this was possible with ZFS. Is it possible using LVM under linux or anything? I don't know a whole lot about any of this stuff.

Also, if I were to start all over with these drives (they currently are all in one striped volume with 3.7TB used: 60% full) what would be the best way to go about it? How would you setup and take advantage of ZFS with these four different hdds? Can you point me to some resources?

Blevo

 

[praecorloth]

I believe a concatenated JBOD array best fits what you're describing. If I understand correctly, you set up a concatenated JBOD using all your drives, and then as you fill it up, one drive fails, you lose only the data/available space that was on that one drive. Whether you can do this in FreeNAS or not, I do not know. But that at least gives you a string to pull on.

For how to start over cleanly with your drives, I feel your pain. It looks like you have some very nicely sized drives, they're just unfortunately different sizes. Were it me, I would probably invest in another 2TB drive and set up a RAID-Z. The 1TB and 1.5TB I'd likely set up in a mirror and use it for experimental storage. Like host virtual machines via an iSCSI target, or experiment with ZFS snapshots or something. The irritating thing about those 1+TB drives is that they have a very good amount of space. But I'm sure you know that already. :) But that's the best I've got for you. Good luck in your endeavor.

 

[stevoblevo]

sounds like a 'concatenated JBOD' is exactly what I'm talking about. I don't know how to do that in FreeNAS or if it's possible. That Drive-Extender I mentioned seemed like a cool thing, although ZFS with its features is cooler. I may have to setup something like you say using 2TB drives and perhaps even 'backing up' important files onto the 1TB (although a true backup wouldn't be on the same system) and use the 1.5TB drive for I-don't-know-what. yeah, if I setup the 1.5TB and 1TB drives in a mirror I'd lose 500GB huh?

I'm interested in playing around with VMs but I'm not sure I want to setup a whole other computer to host them, not sure if I could use the same FreeNAS system to host VMs. I think I read a few threads discussing having virtualbox as a plugin but some people say it doesn't fit well with a NAS solution.

Blevo

thanks for the reply praecorloth.

 

[praecorloth]

Yup, you'd lose that extra 500GB. That's so irritating. Maybe you could just hang on to them until you can get your hands on another 1TB and another 1.5TB and have two more mirrors.

If you feel like playing with virtual machines, you could fire up VirtualBox on your desktop. Then you could set up an iSCSI target using one or both of those spare drives, have your desktop connect to it, and keep all your virtual machine files there.

Alternately if someday you decide you don't mind setting up a dedicated virtual machine box, I highly recommend ProxMox. It's a Linux based appliance OS like VMWare's ESXi, except it's not nearly as picky about its hardware. ESXi is INCREDIBLY picky. Just make sure you can enable your CPU's hardware virtualization on whatever motherboard you buy. I've run in to too may motherboards that don't let you enable the CPU hardware virtualizaiton, and without that, running VMs can suck.