PMX4 - ZFS - zfs_arc_max - Can't exceed 32G?

[dlasher]

New install of PMX4 (4.4.6-1-pve) - backup/restored my containers from pmx3, imported my ZFS pools, and (almost) everything is peachy..

New machine has 4x the RAM, so I'm looking to increase the amount of ram ZFS is allowed to use.. Worked out the math, and increased zfs_arc_max to 64G, by increasing the value in /etc/modprobe.d/zfs.conf.. or did I?

root@pmx8:~# arc_summary.py  | grep zfs_arc_max
        zfs_arc_max                                       34359738368

Hmmm.. it took all my others settings, like zfs_arc_min.. Ok, let's try setting it by hand:

modprobe zfs zfs_arc_max=68719476736

root@pmx8:~# arc_summary.py  | grep zfs_arc_max
        zfs_arc_max                                       34359738368

Am I running into a bug? I can't seem to get it to take a value over 32G?

 

[LnxBil]

Could you please check this:

grep c_max /proc/spl/kstat/zfs/arcstats

 

[dlasher]

dist-upgrade PVE (4.4.15-1-pve), seems to have solved it, no other changes

root@pmx8:~# grep c_max /proc/spl/kstat/zfs/arcstats
c_max  4  68719476736

ARC Size:  1.93%  1.24  GiB
  Target Size: (Adaptive)  100.00% 64.00  GiB
  Min Size (Hard Limit):  6.25%  4.00  GiB
  Max Size (High Water):  16:1  64.00  GiB