Tune and improve the zfs setup

Currently our ZFS nodes are lagging with the replication, and we need to improve the setup to restore those nodes.

There are a few proposals that has to be tested and developed:

• test disk blocksize with 128 kb ( or smaller)
• Create a Terraform module that will allow us to provision a box with 3 disks
• Test zfs compression.

Acceptance criteria:

• develop and test the options to improve our setup with ZFS