Another, which ZFS layout..?

[tmsmith]

Please bare with me on the specifics. I am deciding whether to invest on replacing the smaller drives. I'm looking for input on that as well!

Hardware/environment
16 drive bay case
7x 4TB drives
2x 3TB drives
3x 2TB drives
2x 1.5TB drives
14 total drives so 2 bays are empty.
16 GB RAM (money is tight, is it necessary to have 32GB? Will I see a HUGE performance hit if I don't?)
Uses will include home office backup, media, plex, accessing drives from separate ESXI homelab
2-3 computers accessing the data.

Obviously I have some mismatched drives in there. Here are my thoughts on the situation.

ZFS configurations for each size disks
8(purchase 1 disk) 4TB disks
raidz2 1zpool, 1vdevs of 8 disks
32TB total, 21.8TB usable

6(purchase 4 total, replacing 2x 1.5TB and filling the two empty spaces in the bay) 3TB disks
zraid2, 1zpool, 1vdevs of 6 disks
18TB total, 10.9TB usable

3x 2TB disks (These maybe replaced with 3TB drives if the wife doesn't kill me.)
zraid1, 1zpool, 1vdevs of 3 disks
6TB total, 3.6TB usable

Please feel free to critique and ask questions. Thanks for reading!

PS - A special thanks to soulburn for the clear and precise formatting. Hopefully I made it just as clear.

 

[danb35]

If you combine these into the same zpool, you will always have a RAIDZ1 vdev in that pool, with the reduced redundancy that entails. You could combine the 3 TB and the 2 TB disks into a single RAIDZ2 vdev, and later replace the 2 TB disks with 3 TB disks to expand its capacity.

 

[enemy85]

I guess you will need more ram...

 

[tmsmith]

If you combine these into the same zpool, you will always have a RAIDZ1 vdev in that pool, with the reduced redundancy that entails. You could combine the 3 TB and the 2 TB disks into a single RAIDZ2 vdev, and later replace the 2 TB disks with 3 TB disks to expand its capacity.

Are there any penalties in doing this? I guess my concern is head aches down the road when I get ready to expand.

I guess you will need more ram...

Are you speaking from experience? I'm just curious how much of a performance hit there will be.

 

[enemy85]

Are there any penalties in doing this? I guess my concern is head aches down the wrong when I get ready to expand.



Are you speaking from experience? I'm just curious how much of a performance hit there will be.

Not speaking from experience because my pool is just 9TB, but for what i understood you are planning a total of 35TB pool with only 16gb of ram right? The general thumb rule says around 1gb for tb, obviously it will work the same but ZFS seems to like as much ram as u can so probably u will be a little bit "limited" in the performances, but how much i don't know.

 

[cyberjock]

My main pool is 30TB and I was forced to upgrade to 20GB of RAM for a single user just to be able to do more than 2-3MB/sec. So yeah, without a doubt you are going to need more RAM. Go to 32GB.

 

[tmsmith]

My main pool is 30TB and I was forced to upgrade to 20GB of RAM for a single user just to be able to do more than 2-3MB/sec. So yeah, without a doubt you are going to need more RAM. Go to 32GB.

I'm confused. Are you saying I should expect this type of performance on a configuration such as this with just one user?

8(purchase 1 disk) 4TB disks
raidz2 1zpool, 1vdevs of 8 disks
32TB total, 21.8TB usable

 

[cyberjock]

If you don't have enough RAM, yes. ZFS performance is directly related to RAM. Don't have enough RAM and you can expect performance to be anywhere from 'total and complete shit' to 'just want to slit my wrists and get it over with'. This is why if you read my noobie guide I put a lot of emphasis on RAM. Never sell yourself short unless you are ready and willing to buy more RAM immediately if performance is inadequate.