It is possible to do something like this? (description inside)
I have a freeNAS box that I use essentially for backup purposes of all the machines at a small office.
I have the following disks:
The reason for this is that additional disks were bought every time more space was needed. The best way to use this for me is to have a unique volume and just drop everything there, I'm using JBOD at the moment. The reason for not using redundancy is basically because it's not versatile enough as I need it, ie. if I need more space tomorrow and buy a new disk, I prefer to buy whatever size is best at the moment and just add that space to my total capacity.
Mi problem with this is that if any disk fails I loose everything (obviously). This is not a problem from a data loss standpoint, since this is just a backups machine, I have the data on my main machines. My main problem is that if I loose a disk I have to rebuild the JBOD and backup everything again, which takes many days over the network.
So here is my question, is there a way to build something like a JBOD but that is resilient to loosing a disk in the sense of still having all the information of the remaining disks, so that when I have to backup again I only have to copy the information that was lost on the bad disk?
Additionally, this JBOD volume should accept to be added an additional disk without having to be rebuilt (for the same reason, I would have to re-backup everything if this is not possible).
The short answer is YES, but you won't be able to just take your current disks and put them in and have FreeNAS share them. You'll have to reformat each disk UFS and reload it. It'll also be easier to move your data from your smaller disks to a new larger one and then get rid of the smaller ones over time. The only downside, which you mentioned was acceptable is that if one disks dies, you'll lose the data on that disk, but the other disks & files will still be ok.
That's good. And the long answer?, anywere I can read about it?, because I've searched (without knowing how this feature is called) and found nothing about it.
Originally Posted by protosd
If I just create a JBOD in freeNAS, any failed disks will make my whole volume not to come up.
Rebuilding my setup is not a problem at the moment, since it's something I have to do anyway.
Well I'm not sure about where to find the documentation, I can try and find a link for you.
Have you used VMware? You could make a simple test setup with some virtual disks, for example for your 400G disks, make a 400M disk, for your 1.5T, make a 1.5G disk. Then in FreeNAS go to Storage -> Create Volume, and create a separate volume for each of your disks using the UFS file system. If you haven't used VMware don't worry, it was just a suggestion for you to experiment with how volumes work with FreeNAS. You wouldn't need several physical disks, just the virtual (smaller simulated) disks for testing.
I'm not sure if you can make a ZFS volume with just a single disk, now I'll have to try it. Anyway, each volume you create will be independent of the others, so it won't be like one continuous space with the capacity of all the disks added together. So, now if one disks fails the other volumes still exist with their independent data. You just destroy the volume for the failed disk, put in a new disk and create a new volume and reload the data for that disk.
Does this make sense? Does it sound like what you need?
UPDATE: Here's a link about Volumes, I'll see what else I can find.
Last edited by ProtoSD; 07-10-2011 at 04:32 PM.
From what you're telling me I think it might be what I'm looking for. I'll test on VM (good idea) and let you know.