A major number refers to a type of device, and a minor number specifies a particular device of that type or sometimes the operation mode of that device type.

Example:

# lsdev -Cc tape
rmt0 Available 3F-08-02 IBM 3580 Ultrium Tape Drive (FCP)
rmt1 Available 3F-08-02 IBM 3592 Tape Drive (FCP)
smc0 Available 3F-08-02 IBM 3576 Library Medium Changer (FCP)

# ls -l /dev/rmt* /dev/smc*
crw-rw-rwT 1 root system 38, 0 Nov 13 17:40 /dev/rmt0
crw-rw-rwT 1 root system 38,128 Nov 13 17:40 /dev/rmt1
crw-rw-rwT 1 root system 38, 1 Nov 13 17:40 /dev/rmt0.1
crw-rw-rwT 1 root system 38, 66 Nov 13 17:40 /dev/smc0

User names can only be eight characters or fewer in AIX version 5.2 and earlier. Starting with AIX version 5.3, IBM increased the maximum number of characters to 255. To verify the setting in AIX 5.3 and later, you can extract the value from getconf:

# getconf LOGIN_NAME_MAX
9

# lsattr -El sys0 -a max_logname
max_logname 9 Maximum login name length at boot time True

# chdev -l sys0 -a max_logname=129
sys0 changed

# getconf LOGIN_NAME_MAX
128

A very good article about migrating AIX from version 5.3 to 6.1 can be found on the following page of IBM developerWorks:

http://www.ibm.com/developerworks/aix/library/au-migrate_nimadm/index.html?ca=drs

For a smooth nimadm process, make sure that you clean up as much filesets of your server as possible (get rid of the things you no longer need). The more filesets that need to be migrated, the longer the process will take. Also make sure that openssl/openssh is up-to-date on the server to be migrated; this is likely to break when you have old versions installed.

Very useful is also a gigabit Ethernet connection between the NIM server and the server to be upgraded, as the nimadm process copies over the client rootvg to the NIM server and back.

The log file for a nimadm process can be found on the NIM server in /var/adm/ras/alt_mig.

For example, if you wish to add the bos.alt_disk_install.rte fileset to a SPOT:

List the available spots:

# lsnim -t spot | grep 61
SPOTaix61tl05sp03     resources       spot
SPOTaix61tl03sp07     resources       spot

# lsnim -t lpp_source | grep 61
LPPaix61tl05sp03       resources       lpp_source
LPPaix61tl03sp07       resources       lpp_source

# nim -o showres SPOTaix61tl05sp03 | grep -i bos.alt

# nim -o showres LPPaix61tl05sp03 | grep -i bos.alt
  bos.alt_disk_install.boot_images 6.1.5.2                    I  N usr
  bos.alt_disk_install.rte    6.1.5.1                    I  N usr,root

# nim -o cust -a filesets=bos.alt_disk_install.boot_images
-a lpp_source=LPPaix61tl05sp03 SPOTaix61tl05sp03

# nim -o showres SPOTaix61tl05sp03 | grep -i bos.alt
  bos.alt_disk_install.boot_images
  bos.alt_disk_install.rte 6.1.5.1 C F Alternate Disk Installation

You can restrict a certain user account to only access a single folder. This is handled by file /etc/ftpaccess.ctl. There's a manual page available within AIX on file ftpaccess.ctl:

# man ftpaccess.ctl

# cat /etc/ftpaccess.ctl
useronly: ftp

ftp> site umask 111
200 UMASK set to 111 (was 027)
ftp> site umask
200 Current UMASK is 111

The following piece of code fits nicely in the /etc/profile file. It makes sure the PS1, the prompt is set in such a way, that you can see who is logged in at what system and what the current path is. At the same time it also sets the window title the same way.

H=`uname -n`
if [ $(whoami) = "root" ] ; then
PS1='^[]2;${USER}@(${H}) ${PWD##/*/}^G^M${USER}@(${H}) ${PWD##/*/} # '
else
PS1='^[]2;${USER}@(${H}) ${PWD##/*/}^G^M${USER}@(${H}) ${PWD##/*/} $ '
fi

if [ $(whoami) = "root" ] ; then
PS1='${USER}@(${H}) ${PWD##/*/} # '
else
PS1='${USER}@(${H}) ${PWD##/*/} $ '
fi

To configure IP aliases on AIX:

Use the ifconfig command to create an IP alias. To have the alias created when the system starts, add the ifconfig command to the /etc/rc.net script.

The following example creates an alias on the en1 network interface. The alias must be defined on the same subnet as the network interface.

# ifconfig en1 alias 9.37.207.29 netmask 255.255.255.0 up

# ifconfig en1 delete 9.37.207.29

VIM on many different types of installations will create both swap files and backup files.

How to disable VIM swap and backup files:

Go into your _vimrc file. Add these lines to the bottom:

set nobackup
set nowritebackup
set noswapfile

If you see the following error when running cfgmgr:

Method error (/usr/lib/methods/fcmap >> /var/adm/essmap.out):
        0514-023 The specified device does not exist in the
                 customized device configuration database.

# lsdev -Cc disk | grep 2105

# installp -u ibm2105.rte ibmpfe.essutil.fibre.data ibmpfe.essutil.rte

"The public-domain time zone database contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules. This database (often called tz or zoneinfo) is used by several implementations.

Each location in the database represents a national region where all clocks keeping local time have agreed since 1970. Locations are identified by continent or ocean and then by the name of the location, which is typically the largest city within the region. For example, America/New_York represents most of the US eastern time zone; America/Phoenix represents most of Arizona, which uses mountain time without daylight saving time (DST); America/Detroit represents most of Michigan, which uses eastern time but with different DST rules in 1975; and other entries represent smaller regions like Starke County, Indiana, which switched from central to eastern time in 1991 and switched back in 2006."

The public-domain time zone database is also widely known as the Olson time zone database and is the architecture on which the International Components for Unicode (ICU) and the Common Locale Data Repository (CLDR) time zone support relies.

In previous AIX releases, the method by which the operating system supports time zone conventions is based on the POSIX time zone specification. In addition to this industry standard approach, AIX V6.1 recognizes and processes the Olson time zone naming conventions to facilitate support for a comprehensive set of time zones.

This enhancement leverages the uniform time zone naming convention of the Olson database to offer an intuitive set of time zone values that can be assigned to the TZ time zone environment variable.

Note: Time zone definitions conforming to the POSIX specification are still supported and recognized by AIX. AIX checks the TZ environment variable to determine if the environment variable follows the POSIX specification rules. If the TZ environment variable does not match the POSIX convention, AIX calls the ICU library to get the Olson time zone translation.

The use of the Olson database for time zone support within AIX provides significant advantages over the traditional POSIX rules. One of the biggest advantages is that Olson database maintains a historical record of what the time zone rules were at given points in time, so that if the rules change in a particular location, dates and times can be interpreted correctly both in the present and past. A good example of this is the US state of Indiana, which just began using daylight saving time in the year 2006. Under the POSIX implementation, Indiana would have to set its time zone value to EST5EDT, which would format current dates correctly using daylight saving time, but would also format times from previous years as though they were on daylight saving time, which is incorrect. Use of the ICU API set for time zones also allows for localized display names for time zones. For example, Central Daylight Saving Time would have an abbreviation of CDT for all locales under a POSIX implementation, but under ICU/Olson, it displays properly as HAC (Heure Avancée du Centre) in a French locale.

As in previous AIX releases, system administrators can rely on the Systems Management Interface Tool (SMIT) to configure the time zone by using system defined values for the TZ environment variable. To accomplish this task, enter the main SMIT menu and select System Environments, Change / Show Date and Time to access the Change Time Zone Using System Defined Values menu. Alternatively, the SMIT fast path chtz_date will directly open the Change / Show Date and Time menu. Selecting the Change Time Zone Using System Defined Values option will prompt SMIT to open the Select COUNTRY or REGION menu.