When tuning for performance, the segment size can make a noticeable difference. The segment size is the size of each transaction in kilobytes between the disk controllers and each physical disk. This can be changed under Logical Drive -> Change -> Segment Size.
Clean the wtmp file
Here is a script that removes the oldest entries in the /var/adm/wtmp file, but keeps a reasonable history:
HACMP timestamp inconsistent
If the timestamps between the nodes in a Concurrent VG get out of sync, you can get:
WARNING: The HACMP timestamp file for shared volume group: vg1
is inconsistent with the time stamp in the VGDA for the
following nodes: node1
Enable cluster encryption
For more security you can make your cluster use encryption for inter-node communication with no downtime. Otherwise operations are allowed or rejected based on IP address, hostname, and the cluster rhosts file. And, C-SPOC operations are not encrypted one of the important ones being password changes. Possibly an even better option would be to create a IPsec VPN tunnel between nodes, but I haven’t tested that.
Fixing dead DLPAR
Sometimes your P4 (and maybe P5?) DLPAR goes to lunch and the dynamic menu options don’t appear. To reset everything on the HMC, IBM recommends we run this from the offending LPAR:
/usr/sbin/rsct/install/bin/recfgctIf that doesn’t work, try:
/usr/sbin/rsct/bin/rmcctrl -z
/usr/sbin/rsct/bin/rmcctrl -A
/usr/sbin/rsct/bin/rmcctrl -pList network port speeds
Simple one-liner to list all your network ports negotiated speed:
netstat -v | egrep "Media | \(en"AIX upgrade missing migration option
The Migration Upgrade option is missing when trying to perform an AIX upgrade.
Check the version of each copy of the boot logical volume (hd5). If any copy has the target AIX version or higher, this will cause the migration option to be unavailable.
The King’s Castration
‘Twas the Night of the King’s Castration: the last of the Royal Balls was coming off. All the counts, discounts and no-accounts were sitting around the throne room slinging camel-shit, for in those days, bull-shit was as yet unknown.
Disable Shutdown Event Tracker
Shutdown Event Tracker is enabled by default and supported on all Windows Server 2003 family of operating systems.
Power on/off a blade from the Management Module CLI
If you don’t have access to the web page of the Management Module, or you’re too lazy to walk to a PC, you can ssh into the management module and do it from the CLI.