Oracle Solaris Tunable Parameters Reference Manual

zfs_arc_max

Description

Determines the maximum size of the ZFS Adjustable Replacement Cache (ARC). See also zfs_arc_min.

Data Type

Unsigned Integer (64-bit)

Default

Three-fourths of memory on systems with less than 4 Gbytes of memory

physmem minus 1 Gbyte on systems with greater than 4 Gbytes of memory

Range

64 Mbytes to physmem

Units

Bytes

Dynamic?

No

Validation

Yes, the range is validated.

When to Change

If a future memory requirement is significantly large and well defined, you might consider reducing the value of this parameter to cap the ARC so that it does not compete with the memory requirement. For example, if you know that a future workload requires 20% of memory, it makes sense to cap the ARC such that it does not consume more than the remaining 80% of memory.

Commitment Level

Unstable

Change History

For information, see zfs_arc_max (Solaris 10 Releases).