imikejackson
Cadet
- Joined
- May 26, 2012
- Messages
- 4
I am in the process of building out a FreeNAS 8.x server. I have all the hardware and will be putting it together this weekend. I have a quad core AMD Proc, 8 GB RAM, 6 SATA ports on the Motherboard and a case capable of holding at least 6 drives. 8 possibly. Now the question. I will be using 4x1TB drives for the initial storage.After a bad experience with another RAID device where the actual data structures got corrupted so the whole RAID volume got corrupted I would like to set this up with surviving a drive failure as the top priority. I have read and read and read many posts about ZFS (vdevs, pools, RAIDZ(1, 2, 3)), resilvering times, rebuilding RAIDZs and write performance. My last RAID was hooked up over USB so having this one over Gigabit ethernet should be much faster. The use of the NAS is to hold critical data that can not be lost. I also plan to run either a Time Machine sparse disk image or setup some sort of system to rsync my home folder to the NAS, then setup the NAS to snap shot the first rsync destination to have a "Time Machine" like backup.
I can not decide if I should have 2 x 1TB Mirror vdevs then combine both mirror sets into a ZFS Pool (I think I should get about 2TB of total storage capacity) or go with a RAIDZ2 of all 4 drives (which I think I should still get about 2 TB of storage). I could possibly purchase another pair of 1TB drives to get another mirror set or have a 6 drive RAIDZ2 system. All the drives are of different ages. Some are fairly new (<6months old) and some are about 2 years old.
My analysis is: 2x (2x1TB Mirror vdevs) : I could loose a drive in each mirror and be "safe". Loosing both drives in a mirror would definitely loose that entire vdev and data. Would I loose the entire pool? I also understand that I can expand the ZPool by creating a new vdev with another pair of drives in the future.
Single RAIDZ2 (4x1TB): I could lose any 2 drives and the data and the Pool is Safe? But I think the write performance may be less (how much I don't know) than the first option. I also understand that once the 4 drive vdev is created I can NOT expand that vdev with more drives. I would have to start a whole new vdev to add more storage space which would have to be at least another 4 drive vdev in RAIDZ2 in order to keep the redundancy of the ZPool.
Any practical experience from "production" systems (home or data center) would be greatly appreciated. I lost about 1 TB of data back in January which while not catastrophic did result in the loss of some old data that would have been nice to work with in future projects.
Thanks Again,
Mike Jackson (www.bluequartz.net)
I can not decide if I should have 2 x 1TB Mirror vdevs then combine both mirror sets into a ZFS Pool (I think I should get about 2TB of total storage capacity) or go with a RAIDZ2 of all 4 drives (which I think I should still get about 2 TB of storage). I could possibly purchase another pair of 1TB drives to get another mirror set or have a 6 drive RAIDZ2 system. All the drives are of different ages. Some are fairly new (<6months old) and some are about 2 years old.
My analysis is: 2x (2x1TB Mirror vdevs) : I could loose a drive in each mirror and be "safe". Loosing both drives in a mirror would definitely loose that entire vdev and data. Would I loose the entire pool? I also understand that I can expand the ZPool by creating a new vdev with another pair of drives in the future.
Single RAIDZ2 (4x1TB): I could lose any 2 drives and the data and the Pool is Safe? But I think the write performance may be less (how much I don't know) than the first option. I also understand that once the 4 drive vdev is created I can NOT expand that vdev with more drives. I would have to start a whole new vdev to add more storage space which would have to be at least another 4 drive vdev in RAIDZ2 in order to keep the redundancy of the ZPool.
Any practical experience from "production" systems (home or data center) would be greatly appreciated. I lost about 1 TB of data back in January which while not catastrophic did result in the loss of some old data that would have been nice to work with in future projects.
Thanks Again,
Mike Jackson (www.bluequartz.net)