zfs_arc_min

Description

Determines the minimum size of the ZFS Adjustable Replacement Cache (ARC). See also zfs_arc_max.

Data Type

Unsigned Integer (64-bit)

Default

1/32nd of physical memory or 64 Mbytes, whichever value is larger.

Range

64 Mbytes to zfs_arc_max

Units

Bytes

Dynamic?

No

Validation

Yes, the range is validated.

When to Change

When a system's workload demand for memory fluctuates, the ZFS ARC caches data at a period of weak demand and then shrinks at a period of strong demand. However, ZFS does not shrink below the value of zfs_arc_min. The default value of zfs_arc_min is 12% of memory on large memory systems and so, can be a significant amount of memory. If a workload's highest memory usage requires more than 88% of system memory, consider tuning this parameter.

Commitment Level

Unstable

Change History

For information, see zfs_arc_min (Solaris 10 Releases).