System Adm » Aix

AIX and user access denied

Lincoln Zuljewic Silva — Wed, 19 May 2010 20:11:00 +0000

AIX has a security feature named unsuccessful_login_count (/etc/security/lastlog) . It is an user account feature that count the number of unsuccessful login attempts and it works conjunction with the user's loginretries (/etc/security/user) attribute.

So, if you configure the loginretries=5, the user will not be able to log in after 5 retries. To enable the login again, you should reset the unsuccessful_login_count parameter by editing the file /etc/security/lastlog or with the following command:

# chsec -f /etc/security/lastlog -a unsuccessful_login_count=0 -s foobar

You can identify this problem by the following message in syslog:

May 19 15:42:41 aixbox auth|security:info sshd[7884888]: Login restricted for foobar: 3004-303 There have been too many unsuccessful login attempts; please see \tthe system administrator.

Physical memory in AIX

Lincoln Zuljewic Silva — Thu, 18 Feb 2010 11:56:21 +0000

To check the amount of physical RAM that a AIX Server has, you can use the following commands:

# lsattr -El sys0 | grep realmem realmem 16121856 Amount of usable physical memory in Kbytes

or

# lsattr -El mem0 goodsize 15744 Amount of usable physical memory in Mbytes False size 15744 Total amount of physical memory in Mbytes False

# prtconf|grep "Memory Size" Memory Size: 15744 MB Good Memory Size: 15744 MB

Disable file size limit in AIX

Lincoln Zuljewic Silva — Fri, 04 Dec 2009 11:58:48 +0000

By default, if you try do copy/create a file larger than 2Gb in AIX, you will get a “file too large” message. That happen because AIX have a default limit of 2Gb for files.

To disable (or increase) this limit, edit /etc/security/limits and change the parameter fsize to “-1” or whatever value you want.

You can change it in “default” to apply to all users or change it to a specific user.

Remember that the file system should be JFS2.

Forcing an user changing the password on AIX

Lincoln Zuljewic Silva — Mon, 30 Nov 2009 21:33:25 +0000

Forcing an user changing the password on AIX

On AIX, you can use the following commands to unlock na user and force it to change it’s password on first logon:
# pwdadm -f ADMCHG USER