Edit: Some links no longer work.
Originally posted September 9, 2014 on AIXchange
It was an ordinary day. I needed to take a mksysb. Only this time, I was getting an error.
/usr/bin/mkszfile[1266]: FS_MIN_LOG = FS_MIN_LOG *
20480 : 0403-009 The specified number is not valid for this command.
0512-008 mksysb: The mkszfile command failed. Backup canceled.
I checked ps –ef | grep mkszfile and saw that it was still trying to run, but it wasn’t doing anything. I went ahead and killed the process.
The error message didn’t tell me much, but fortunately a quick web search yielded a few different ideas and suggestions, including this. Then I found an entry from this blog (that advertises “Unix tips, food reviews and astronomy”):
“A google search revealed it was probably a bad FS causing the problem. To identify which one(s), I ran the following: sh -x /usr/bin/mkszfile
“This gave the full output and I could see which file system it was processing when it crashed. I then unmounted the file system, [ran fsck] and remounted it before re-running the mkszfile.
“In this case there were four file systems it complained about and after [running fsck] them the mkszfile ran through ok. A re-run of the mksysb then worked ok.”
That seemed simple enough, so I gave it a try. It went exactly as described in the blog post. After running the command, the filesystem that was causing me issues was the last one that was processed before the error occurred. Luckily for me that filesystem wasn’t being used at the time, so I just unmounted it, ran fsck –y /filesystem and then remounted it. Then the mksysb worked as expected.
Now when the next person does a web search on this error code, there will be two sources confirming that running sh –x /usr/bin/mkszfile is the way to locate the filesystem that’s causing you problems.