ZOL - Ubuntu - Memory Starvation?

[Larry Smith]

Two new NAS builds using ZOL on Ubuntu 14.04LTS. One NAS 32GB and the other 16GB. I have tuned the ARC settings but each system at different times will just lock up and nothing in syslog in regards to what or why. These NAS builds are being used for NFS datastores for ESXi5.5 environment. 

On my 32GB NAS I have /etc/modprobe.d/zfs.conf set as below and the 16GB NAS is half of these settings.

# My tweaks for ZFS Performance

options zfs zfs_prefetch_disable=1

options zfs zfs_txg_timeout=5

options zfs zfs_vdev_async_write_max_active=1

options zfs zfs_vdev_async_write_min_active=1

options zfs zfs_vdev_async_read_max_active=1

options zfs zfs_vdev_async_read_min_active=1

options zfs zfs_vdev_sync_write_max_active=1

options zfs zfs_vdev_sync_write_min_active=1

options zfs zfs_vdev_sync_read_min_active=1

options zfs zfs_vdev_sync_read_max_active=1

#### Memory tuning - entered in bytes

# zfs_arc_min 1/2 of zfs_arc_meta_limit

options zfs zfs_arc_min=268435456

# zfs_zrc_max 1/2 or 3/4 of system memory

options zfs zfs_arc_max=17179869184

# zfs zfs_arc_meta_limit 1/4 of zfs_arc_max

options zfs zfs_arc_meta_limit=536870912

Thoughts? Anyone else experiencing the same issues?

Thanks in advance.