Twitter Yields More AIX Tips

Edit: Links no longer work.

Originally posted July 12, 2011 on AIXchange

Once again, Twitter had some interesting things to tell me when I searched in #aix.

I got a laugh from this Anthony English tweet:

“Found reference to #AIX 5.4 in doco http://t.co/FUQCAuU AIX 5.4 never released – 6.1 & #Power6 took its place.”

Sure enough, check this out:

“Enhanced JFS is the default file system for 64-bit kernel environments. Due to address space limitations of the 32–bit kernel, Enhanced JFS is not recommended for use in 32-bit kernel environments. Support for datasets has been integrated into JFS2 as part of AIX Version 5.4. A dataset is a unit of data administration.”

I wonder when that reference will be changed.

Nigel Griffiths tweeted about his article on keeping VIO servers up to date.

Chris Gibson had a tweet about extending error log size in AIX. As noted here, by default, AIX sets its error log size at 1 MB. However, since it’s a circular log, useful diagnostic information is often overwritten. The size of the log can be increased dynamically by use of the  “errdemon” command in AIX.

You’ll see here the current log size with the 1 MB restriction:

# /usr/lib/errdemon -l
Error Log Attributes
——————————————–
Log File                /var/adm/ras/errlog
Log Size                1048576 bytes <<<
Memory Buffer Size      32768 bytes
Duplicate Removal       true
Duplicate Interval      10000 milliseconds
Duplicate Error Maximum 1000

Use this command to reset the maximum log size to 40 MB:

# /usr/lib/errdemon -s 41943040

And here’s how to confirm the maximum size:

# /usr/lib/errdemon -l
Error Log Attributes
——————————————–
Log File                /var/adm/ras/errlog
Log Size                41943040 bytes <<<
Memory Buffer Size      32768 bytes
Duplicate Removal       true
Duplicate Interval      10000 milliseconds
Duplicate Error Maximum 1000

Finally, this tweet linked to a nice way to “retrieve all HBA WWNs on AIX”:

for i in $(lsdev -C|awk ‘/^fcs/ {print $1}’);do echo “$i\t$(lscfg -vl
$i|awk -F. ‘/Network Address/ {print $NF}’)” ;done

fcs0    C05092032BFC00C0
fcs1    C05092032BFC00C2
fcs2    C05092032BFC00C4
fcs3    C05092032BFC00C6

As always, it pays to follow AIX pros on Twitter. You’ll find all kinds of interesting facts, tips and tricks.