I got my nands on an old Fujitsu MX microserver and decided to give proxmox a spin. Some notes:

4 x HDD from old laptops perform well without sync… use with caution and have backups.

root@proxmox:~# pveperf /XXX-raid/
CPU BOGOMIPS: 55998.56
REGEX/SECOND: 4163519
HD SIZE: 899.00 GB (XXX-raid)
FSYNCS/SECOND: 147.26
DNS EXT: 38.15 ms
DNS INT: 20.83 ms (home)

root@proxmox:~# zfs set sync=disabled XXX-raid

root@proxmox:
~# pveperf /XXX-raid/
CPU BOGOMIPS: 55998.56
REGEX/SECOND: 4173357
HD SIZE: 899.00 GB (XXX-raid)
FSYNCS/SECOND: 3986.33
DNS EXT: 39.74 ms
DNS INT: 21.05 ms (home


adding two SSDs in front of two slow harddisks have the same effect. (add them as ZIL for IOPS, add them as LOG to mitigate write delays / latency)

benchmark with pveperf first, then with fio

Mind your ashift. 12 == 4k, 9 == 512b

fastest way to zap disks to use them:
gdisk /dev/sda
'x' for extra commands
'z' for zap