ORA-27301: OS failure message: Not enough space

Last week I experienced below error on solaris server.

*** SERVICE NAME:(SYS$BACKGROUND) 2009-02-05 20:14:41.719
*** SESSION ID:(169.1) 2009-02-05 20:14:41.719
*** 2009-02-05 20:14:41.719
Process startup failed, error stack:
ORA-27300: OS system dependent operation:fork failed with status: 12
ORA-27301: OS failure message: Not enough space
ORA-27302: failure occurred at: skgpspawn3
*** 2009-02-05 20:15:07.770
Process startup failed, error stack:
ORA-27300: OS system dependent operation:fork failed with status: 11
ORA-27301: OS failure message: Resource temporarily unavailable
ORA-27302: failure occurred at: skgpspawn5
*** 2009-02-05 21:39:15.391
Process startup failed, error stack:
ORA-27300: OS system dependent operation:fork failed with status: 12
ORA-27301: OS failure message: Not enough space
ORA-27302: failure occurred at: skgpspawn3


On checking system logs (/var/adm), dmesg and others , Noticed system was nearly out of swap.
As part of immediate resolution bounce database to kill all defunct processes and started the database again.

Metalink note 579365.1 described exactly the same issue