Category Archives: SysAdmin

NOOBS for Raspberry Pi

Where did the day go? Down the rabbit hole of SysAdmin work and so, while not particularly wasted, wasn’t time well spent.

It started when I decided to upgrade my server to Fedora 30, surprisingly enough, that went smoothly, took a coffee break and a lunch hour and everything came up smelling like a rose. I was due after last summer on the cosmic break board.

While that was going on was going on I decided to post a blog entry and that was when I went down the rabbit hole. First I updated all the blogs and then turned to the article and started by heading off to download an infographic from a link I was emailed, but as it was a tracker, it was blocked by my Pi-hole. I attempted to temporarily disable the pihole and found I could not login via the web interface. Using SSH, I was able to determine I had run out of storage space…but why?

I tracked it back to using the version of software, NOOBS that came with it. Lazy and as a result the 8GB card had only 5GB of storage and it was full with the base install. I certainly could have simply deleted a few of the apps (Mathematica and Wolfram Alpha being the largest unused apps I generally pull off) but as it is a rainy day, I optimistically put off gardening to between showers, little sensing how long this was going to take to put a clean copy of Raspbian on it.

It went very slowly, I forgot why I like to pull of those apps, and that old memory card is left to a slow older standalong Pi duties like Pi-hole, the update took forever but eventually I was rewarded with a reloaded from scratch Pi-Hole with plenty of space.

Now I was ready to make a blog entry and be quick about it as the update to Fedora 30, which takes at least a coffee break and full lunch to complete was already done. Except the Pi I used for the Pi-Hole to update wasn’t starting the HDMI. Aha I thought, the old HDMI recognition issue I thought, and sure enough the /boot/config.txt file was mangled slightly with a comment that NOOBS had made changes, argh, I might as well reload this one as the rain continued and so I did. It turned out that my new Pi case with a fan and everything has simply been reluctant to let the HDMI cable go all the way in and by the time I solved that I had updates going everywhere.

So after all of that, I don’t have time to post the entry to the blog, didn’t get any gardening done, didn’t get to read a little, and I am back to where I was at the start of the day although up to date in a maintainable fashion.

I suppose it is worth it; however, I have found that my view has completely changed. I no longer think it reasonable to spend time on System Administration, life is too short.

Hmmmm.

SOLVED: tt-rss Update Deamon Not Running after Update

I solved the problem where after an update tt-rss displayed a red box “Update Deamon not Running” [regrets for not having a screen shot of that].

What I found, and I am sure it is in the documentation is that in the tt-rss/lock directory, there are two files: update_deamon.lock and update_deamon.stamp and mind had significantly different time stamps [ ls -l * ], one immediately after the update. I deleted them both and restarted my httpd.service and the deamon ran successfully after that.

I would post this on a support forum or upvote wherever I found it; however, I just took a quick look around for an error log and lock files to warm up my awareness of key issues prior to checking those. Yeah me!

Moodle 3.6 Log Problems

I am having backup problems, and was troubleshooting other issues earlier in the year, and my resolution at the semester was to export all the classes, create a clean database and reload the classes thereby getting rid of any cruft issues from a not-as-old-as-one-might-think Moodle setup.
The day started easily but I kept getting a nagging feeling that the classes were to large and found a mdl_log table in the database with entries from years ago and quite a large number of them. Apparently Moodle upgraded and did not remove the old log. So I used TRUNCATE and emptied the table. Of course I had researched the table and implications, backed up the database and so forth.
I then changed the log retention date to 2 days and ran cron repeatedly and was unable to trim the mdl_logstore_standard_log file at all and it was huge as well. I finally used TRUNCATE on that file as well.
I am a week along and the log files are running fine, no logs are appearing in the old table and I am hopeful the current logs are being pruned in accordance with the configuration.
I still haven’t resolved the backup issues and I am sure I have something else in the database and I pass on the obvious lesson that a Moodle site should be completely rebuilt annually, or on some regular schedule, to ensure that old data/tables are pruned or removed effectively.
If I could just resolve the backup stretching out as well as the backups in some, but not all, classes being retained I would have this system under control. Soon though.

Moodle Automated Backup Problems

I am back to troubleshooting, yet again, the problem of Moodle backups taking forever and a day. An actual day, for very small courses.

A second problem occurring with the automated backups is that the old backups are not being purged so the file system is filling up with them rather than purging/pruning them. I am solving the problem at present by a weekly manual clean up.

I could simply pour over the forums for an answer, which has not produced results. I could look at tables/records in the actual database for anomalies and that strikes me as time consuming. Or I could wait until the semester break in two weeks and backup and export each class and all the information and create a brand new instance of Moodle and restore the classes into that and see if that leaves the cruft and problems behind.

I am going with that alternative in the interests of cleaning up any other problems I am not yet aware of that affect other areas including performance.

Will post my results.

Tiny Tiny RSS: Building my own RSS Reader

ttrssI finally setup my TinyTinyRSS server following the guidelines on LifeHacker outlined in this article.  The original plan, when Google Reader shut down, was to have my own RSS server and not be beholden to someone disappearing.

Next on the list is to find a bookmarking tool that wouldn’t go away.

While I have the basic system setup and am going for coffee now I have a few things to still look at:

The feature set – read more about them here, the Android app, the Chrome extension, and more third-party supported apps.

I haven’t set it up for auto update.  I am running the PHP update script in a terminal window for now.  I think I may simply use the client to update itself by setting it as a pinned tab, it would update every 30 minutes then.

Open up your config.php file in a text editor, and scroll down “SIMPLE_UPDATE_MODE” and change its flag from “false” to “true.” This will make TTRSS update your feeds for you every 30 minutes (by default, you can change this in the Preferences) as long as you’re logged in. Set it as a pinned tab, and you’ll never have a problem.

And I have the final sheet of items I may look at someday, depending on whether I actually switch in the next 7 days from Feedly to it.

Additional Reading