eweber1969
Cadet
- Joined
- Apr 26, 2012
- Messages
- 2
Hi All,
I had a few questions about combining 2 vdev's (using raidz1) into a single zpool. My questions are based on the following configuration...
vdev1 = 2TB + 2TB + 2TB (available space = 4TB)
vdev2 = 1TB + 1TB + 1TB (available space = 2TB)
1) please confirm that the total available space would be 6TB, and that the smaller vdev does not limit the total capacity of the zpool.
2) do files get striped across both vdev's, or does freenas decide that it will write a file to either one vdev or the other?
3) I would hope that the answer to question #2 is that freenas stripes a file across one or the other, but not both. I'm asking in regards to drive failure. I would assume that I could lose (1) one drive from vdev1 OR (2) one drive from vdev2 OR (3) one drive from vdev1 and one drive from vdev2 and that everything would still be recoverable.
4) What if I lost 2 drives from vdev1? I understand that vdev1 would be hosed, but would it affect the files on vdev2?
5) Since I don't have 6 drives laying around, I would first have to create vdev1, then copy all my existing files to freenas. Then I would add vdev2 (with the now empty hdd's). In my mind, vdev1 would be full and vdev2 would be empty. This feels unbalanced. Does this mean that only future writes to the zpool would begin utilizing vdev2 (i guess it depends on the answer to question #2)? Or does freenas fill up vdev1 before it starts using vdev2.
Thank you very much for your help!
Eric
I had a few questions about combining 2 vdev's (using raidz1) into a single zpool. My questions are based on the following configuration...
vdev1 = 2TB + 2TB + 2TB (available space = 4TB)
vdev2 = 1TB + 1TB + 1TB (available space = 2TB)
1) please confirm that the total available space would be 6TB, and that the smaller vdev does not limit the total capacity of the zpool.
2) do files get striped across both vdev's, or does freenas decide that it will write a file to either one vdev or the other?
3) I would hope that the answer to question #2 is that freenas stripes a file across one or the other, but not both. I'm asking in regards to drive failure. I would assume that I could lose (1) one drive from vdev1 OR (2) one drive from vdev2 OR (3) one drive from vdev1 and one drive from vdev2 and that everything would still be recoverable.
4) What if I lost 2 drives from vdev1? I understand that vdev1 would be hosed, but would it affect the files on vdev2?
5) Since I don't have 6 drives laying around, I would first have to create vdev1, then copy all my existing files to freenas. Then I would add vdev2 (with the now empty hdd's). In my mind, vdev1 would be full and vdev2 would be empty. This feels unbalanced. Does this mean that only future writes to the zpool would begin utilizing vdev2 (i guess it depends on the answer to question #2)? Or does freenas fill up vdev1 before it starts using vdev2.
Thank you very much for your help!
Eric