Category Archives: Sys Admin

Material related to systems administration.

php -d xdebug.profiler_enable=1

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So to enable profiling on the command line run your script in PHP like this:

php -d xdebug.profiler_enable=1 /path/to/script.php

You need to have configured xdebug in php.ini, I do it with a file in /etc/php/7.2/cli/conf.d/xdebug.ini that looks like this:

;xdebug.profiler_enable = 0
xdebug.profiler_output_dir = "/tmp/xdebug"
xdebug.profiler_output_name = "cachegrind.out.%p"

Note: you can enable profiling for all scripts with xdebug.profiler_enable = 1

GRUB_CMDLINE_LINUX_DEFAULT

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I had a system which failed to boot. The last lines printed to the screen, which were not relevant to the problem, were:

 [19.957783] async_tx: api initialized (async)
 [20.899732] Btrfs loaded, crc32c=crc32c-intel

Then a little bit later:

 [32.469926] random: crng init done
 [32.470551] random: 7 urandom warning(s) missed due to ratelimiting

The full problem description is here. And the solution is here (careful about the typo on that page, the only relevant setting is GRUB_CMDLINE_LINUX_DEFAULT).

Basically the problem was a bogus GRUB_CMDLINE_LINUX_DEFAULT setting in /etc/default/grub applied by my salt config. I fixed the setting which fixed the issue.

ata5: SATA link down (SStatus 1 SControl 300)

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So I was getting error messages like this:

Jun 15 02:56:45 trust kernel: [  127.165096] ata5: SATA link down (SStatus 1 SControl 300)
Jun 15 02:56:45 trust kernel: [  127.165105] ata5: EH complete
Jun 15 02:56:45 trust kernel: [  127.174488] ata5: exception Emask 0x10 SAct 0x0 SErr 0x4040000 action 0xe frozen
Jun 15 02:56:45 trust kernel: [  127.178637] ata5: irq_stat 0x00000040, connection status changed
Jun 15 02:56:45 trust kernel: [  127.182700] ata5: SError: { CommWake DevExch }
Jun 15 02:56:45 trust kernel: [  127.186842] ata5: hard resetting link

The ‘ata5’ indicated SATA disk 5, being /dev/sde. Depending on which disk is affected you might see ‘ata1’, ‘ata2’, ‘ata3’, ‘ata4’, etc.

The problem seemed to be a loose cable. I have removed that drive (and its cables) and the problem has gone away.

Omitting date completed from MySQL dump file

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By default when you run a dump with ‘mysqldump’ the date of the dump is appended to the file, e.g.:

jj5@love:~/desktop/experiment$ udiff *
--- dbt__jj_dev_1__svn_jdrepo.1.sql     2019-06-11 18:11:13.267758230 +1000
+++ dbt__jj_dev_1__svn_jdrepo.2.sql     2019-06-11 18:12:03.856075974 +1000
@@ -32,4 +32,4 @@
 /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
 /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

--- Dump completed on 2019-06-10 21:59:44
+-- Dump completed on 2019-06-10 12:06:49

This causes dumps for a single database that has not changed to have two dumps which differ. It’s better to have dumps from the same unchanged database to be the same. To facilitate that add the –skip-dump-date option when running ‘mysqldump’.

See here for the back-story.

Fixing character encoding issue in ViewVC

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So I was having an issue with ViewVC wherein UTF-8 content (a copyright symbol) was being garbled in the web browser.

I chased a number of red herrings (Content-Type headers, http-equiv, XHTML vs HTML5) but eventually found the culprit in the viewvc.conf settings.

I needed to change the ‘detect_encoding’ setting from ‘1’ to ‘0’. Once that was done my content was presented correctly:

## detect_encoding: Should we attempt to detect versioned file
## character encodings?  [Requires 'chardet' module, and is currently
## used only by the syntax coloration logic -- if enabled -- for the
## 'markup' and 'annotate' views; see 'enable_syntax_coloration'.]
##
# 2019-06-02 jj5 - OLD: this was bollocksing things up...
#detect_encoding = 1
# 2019-06-02 jj5 - NEW: so I changed it...
detect_encoding = 0
# 2019-06-02 jj5 - END

WARN: Duplicate profile ‘Dovecot IMAP’, using last found

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So when running ‘ufw’ I was getting this error: WARN: Duplicate profile ‘Dovecot IMAP’, using last found

The issue was duplicate rules were specified in:

/etc/ufw/applications.d/dovecot-core

And:

/etc/ufw/applications.d/dovecot-imapd

The solution for me was to delete the second file (imapd) as it was covered by the previous file (core).

A folder named ~/.cache/kioexec/krun/13821_0/ already exists

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2017-12-09 jj5 – TODO: document this on my blog…

On Debian GNU/Linux 9.1 (stretch) when I try to open an *.desktop (application/x-desktop) link in a browser I get:

A folder named ~/.cache/kioexec/krun/13821_0/ already exists.

Searching for:

A folder named kioexec krun already exists

turned up diddly squat.

I solved the issue (for me) by changing:

System Settings -> Personalization -> Applications -> Default Application s-> Web Browser

from:

Open http and https URLs in an application based on the contents of the URL

to:

Open http and https URLs in the following browser: firefox

Installing .NET on Debian 9

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After installing Visual Studio Code I followed the instructions from .NET Tutorial – Hello World in 10 minutes, basically:

wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.asc.gpg
sudo mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/
wget -q https://packages.microsoft.com/config/debian/9/prod.list
sudo mv prod.list /etc/apt/sources.list.d/microsoft-prod.list
sudo chown root:root /etc/apt/trusted.gpg.d/microsoft.asc.gpg
sudo chown root:root /etc/apt/sources.list.d/microsoft-prod.list

Then:

sudo apt-get update
sudo apt-get install dotnet-sdk-2.1

Then for example to create a new console project:

dotnet new console -o myApp
cd myApp

I ended up reading MICROSOFT SOFTWARE LICENSE TERMS for the MICROSOFT .NET LIBRARY which included this doozy:

The software may collect information about you and your use of the software, and send that to Microsoft.

Ah, Microsoft. You haven’t changed.

I found some notes about how to disable telemetry:

Telemetry
———
The .NET Core tools collect usage data in order to help us improve your experience. The data is anonymous and doesn’t include command-line arguments. The data is collected by Microsoft and shared with the community. You can opt-out of telemetry by setting the DOTNET_CLI_TELEMETRY_OPTOUT environment variable to ‘1’ or ‘true’ using your favorite shell.

Read more about .NET Core CLI Tools telemetry: https://aka.ms/dotnet-cli-telemetry

I have added the opt-out environment variable via jj5-bin.