It has been one of those weeks. Not fun, to many hours worked, personal events missed, you know the kind of week I am talking about. If not…what do you do for a living?!
Despite all the pain and stress this week has resulted in Progress, an increased understanding of certain products and new ways to use old tools. I won’t share the details of my story, just insert yours here, but I will share/document the lessons and commands I learned or rediscovered. Here we go…
Starting a long running process from home last night around 9PM and forgetting to start screen…priceless! At 5:30AM this morning the process was still chugging along, with from my calculations would be running for another 18+ hours. Off to work with no way to grab the terminal (an ssh session), what to do? Why use strace of course! Here is how:
strace -pPROCESS_PID -s9999 -e write ie: strace -p3918 -s9999 -e write
Now even if my ssh session dies at home, I can still see the process output and know when it finishes and if it had any problems. Yes, I could have piped output to a file, you never forgot anything after working for 15+ hours?
Dealing with a system that had some package inconsistencies and a yum update that failed, followed by a package-utils –cleandupes that erased many complete packages, I thought about using the ‘yum history’ command to revert the system until I read this: “Use the history option for small update rollbacks.” Here are some of the commands I used which due to the systems package inconsistencies did not perform as expected.
# yum check # package-cleanup --cleandupes # yum-complete-transaction # yum check # package-cleanup --problems # rpm -Va --nofiles --nodigest # yum distribution-synchronizatio
The rest is pretty standard stuff, at least not worth noting in this post. The end result this week is a lot of lessons learned and a much deeper understanding for an application that I support on my server. In all, ignoring the backlog, I’d say that is what progress looks like.