This is a note-to-self really. When playing around with Oracle and something’s not working - RTFAL: Read The Flippin Alert Log!
After resizing a VM I was getting this problem: [sourcecode] [oracle@RNMVM01 ~]$ sqlplus / as sysdba
SQL*Plus: Release 220.127.116.11.0 Production on Sat Apr 24 17:44:44 2010
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup nomount ORA-00845: MEMORY_TARGET not supported on this system SQL> [/sourcecode]
I spent longer than I should have reading around on google, hitting various pages which all talked around memory management and /dev/shm
If I’d followed the logical process, I’d have checked the alert log: [sourcecode] Starting ORACLE instance (normal) WARNING: You are trying to use the MEMORY_TARGET feature. This feature requires the /dev/shm file system to be mounted for at least 536870912 bytes. /dev/shm is either not mounted or is mounted with available space less than this size. Please fix this so that MEMORY_TARGET can work as expected. Current available is 529969152 and used is 0 bytes. Ensure that the mount point is /dev/shm for this directory. memory_target needs larger /dev/shm [/sourcecode]
Following the syntax from here I duly allocated the space as Oracle requested: [sourcecode] [root@RNMVM01 ~]# mount -t tmpfs shmfs -o size=536870912 /dev/shm [/sourcecode]
and now Oracle was happy: [sourcecode] SQL> startup nomount ORACLE instance started.
Total System Global Area 535662592 bytes Fixed Size 1337720 bytes Variable Size 402654856 bytes Database Buffers 125829120 bytes Redo Buffers 5840896 bytes [/sourcecode]
As a ‘hack’ when it comes to Oracle server stuff, I have to say it’s a pleasure to work with most of the time, lots of helpful logs & documentation :-)