[REQUEST] zpool stats monitoring method change.

[reefland]

Per #374 which is monitoring ZFS file system via /proc/spl/kstat/zfs/*pool_name*/io this will not work for long term monitoring. This has already been removed from current builds of ZFS:

$ zfs version
zfs-2.1.5-1
zfs-kmod-2.1.5-1

$ ls -l /proc/spl/kstat/zfs/vault
total 0
-rw-r--r-- 1 root root 0 Jun 30 17:40 dmu_tx_assign
-rw-r--r-- 1 root root 0 Jun 30 17:40 iostats
-rw-r--r-- 1 root root 0 Jun 30 17:40 multihost
-rw-r--r-- 1 root root 0 Jun 30 17:40 objset-0x183
-rw-r--r-- 1 root root 0 Jun 30 17:40 objset-0x195b1
-rw-r--r-- 1 root root 0 Jun 30 17:40 objset-0x36
-rw-r--r-- 1 root root 0 Jun 30 17:40 objset-0x3699
-rw-r--r-- 1 root root 0 Jun 30 17:40 objset-0x86
-rw------- 1 root root 0 Jun 30 17:40 reads
-rw-r--r-- 1 root root 0 Jun 30 17:40 state
-rw-r--r-- 1 root root 0 Jun 30 17:40 txgs

These links appear relevant to its removal:
openzfs/zfs#12212
openzfs/zfs@371f88d

Prometheus Node Exporter for ZFS was using this as well:
prometheus/node_exporter#2068

[aristocratos]

@simplepad You wanna take a look at this?

[simplepad]

Yes, I'm working on it.