shmsys:shminfo_shmmax

Description

Maximum size of system V shared memory segment that can be created. This parameter is an upper limit that is checked before the system sees if it actually has the physical resources to create the requested memory segment.

Attempts to create a shared memory section whose size is zero or whose size is larger than the specified value will fail with an EINVAL error.

Data Type

Unsigned long

Default

8,388,608

Range

0 - MAXINT on 32-bit systems, MAXINT64 on 64-bit systems

Units

Bytes

Dynamic?

No. Loaded into shmmax field of shminfo structure.

Validation

None

When to Change

When the default value is too low. Generally changed at the recommendation of software vendors, but unless the size of a shared memory segment needs to be constrained, setting this parameter to the maximum possible value has no side effects.

Commitment Level

Unstable