Rethinking my ZFS pool setup [advice on plan requested]

[MikeGrok]

@Exard3k

short-term this might work…but as soon as the mirror vdev is at cap and RaidZ vdev isn’t, you have both an imbalance and revert back to old write speed. And you can’t remove the mirror either.

The OP was concerned that since he had made his initial array a 6 drive raidZ2, all of his future additions to the pool would also have to be in sets of 6 drive raidz2. I was just indicating that he could add a mirrors to the pool, or any set of drives with some redundancy. While it is possible to add individual drives, HDDs are fairly unreliable, and that is not advised.

For some of my thoughts on using mirrors or higher sets of redundancy on a production zfs server… (overkill for this user):

ThatGuyB's rants

I was working at IX systems (primary developers of FreeNAS) a few years ago, and they liked to have at least 2 extra data drives in any given commercial data set. Where raidz2 was not cutting it, ie people using a large raid array instead of an SSD for a database or to back the boot drives of VMs, they would have pools of mirrors. ZFS does mirror …

ThatGuyB's rants

By the way when making a stripe of mirrors, you can start with dual drive mirrors, then add drives to existing mirrors if your need for read speed increases, or add more mirrored vdevs as you need more space. The reason for a 3 drive mirror per vdev is that so that the pool remains online and high performance even as drives fail, get swapped out, a…

My thoughts on dedupe:

ThatGuyB's rants

ZFS dedupe is crazy dangerous. IXSystems had a client who backed virtual machines on the zfs server with dedupe. They had over 60 to 1 compression until they filled up their ram with their dedupe table. The problem was that the computer was already the most high end computer on the market. They had to wait 5 months for intel to release a new server…

I think I need to make my own thread with my brain dumps.