Kevin Horton
Guru
- Joined
- Dec 2, 2015
- Messages
- 730
I am planning the vdev scheme for a remote backup server. My current main system will be repurposed to be the backup server, and I will build a new, more capable, main system. The intended backup system can support 8 disks, which will be 4TB WD Reds. Normally, I'd be happy with RAIDZ2, but given that it is offsite, and I spend quite a bit of time traveling on business, I cannot be sure to be able to quickly replace a failed disk. The system may have to run with a failed disk for three or more weeks before I could replace it. I am not happy with the potential single disk redundancy for a long period.
I am looking at two options to assure a robust, reliable system even after one disk has failed:
8 disks in RAIDZ3, or
7 disks in RAIDZ2 + one spare disk. I will have admin access via VPN, and could remotely replace a failed disk with the spare disk if required.
I have no experience with RAIDZ3. If a disk fails, does it work about as well as a RAIDZ2 system? Are there any downsides to running a RAIDZ3 system for a long period with one failed disk?
I am leaning towards RAIDZ3, but would appreciate any comments.
Of course, perhaps I should keep in mind that this is a backup server, and the world won't end if it fails, as all the data already exists in one or two additional places. Maybe I should use 8 disks in RAIDZ2, to allow more room for growth in the size of the backups. I've thrown out any thoughts of RAIDZ1, as the network connection at the backup site is not fast, and it would take a very long period to copy the data back on to the server if I ever lose the backup pool. I would have to bring the system back to the main site for a few days to reload the data.
I am looking at two options to assure a robust, reliable system even after one disk has failed:
8 disks in RAIDZ3, or
7 disks in RAIDZ2 + one spare disk. I will have admin access via VPN, and could remotely replace a failed disk with the spare disk if required.
I have no experience with RAIDZ3. If a disk fails, does it work about as well as a RAIDZ2 system? Are there any downsides to running a RAIDZ3 system for a long period with one failed disk?
I am leaning towards RAIDZ3, but would appreciate any comments.
Of course, perhaps I should keep in mind that this is a backup server, and the world won't end if it fails, as all the data already exists in one or two additional places. Maybe I should use 8 disks in RAIDZ2, to allow more room for growth in the size of the backups. I've thrown out any thoughts of RAIDZ1, as the network connection at the backup site is not fast, and it would take a very long period to copy the data back on to the server if I ever lose the backup pool. I would have to bring the system back to the main site for a few days to reload the data.