When I put some apt config file into /etc/apt/preferences.d of my Ubuntu 20 LTS desktop, it is ignored (cannot be seen in the output of apt-config dump).
When I instead put the same *.conf file into the /etc/apt/apt.conf.d directory, it is honored (can be seen in the output of apt-config dump).
So what is the purpose of the /etc/apt/preferences.d directory in Ubuntu ?
It seems the journal files in my Ubuntu 18 LTS server are not compressed despite compression is enabled by default (I did not change it in /etc/systemd/journald.conf) and journalctl claims to see compressed files:
# journalctl --header | grep PRESS | uniq
Incompatible Flags: COMPRESSED-LZ4
# journalctl --disk-usage
Archived and active journals take up 4.0G in the file system.
# journalctl -o verbose | wc
4 GB in 90 Mio lines # about the same size as the journal files itself
# journalctl -o verbose | gzip | wc -c
193 MB # reduced by a factor of 20
grep -v '^#' /etc/systemd/journald.conf
[Journal]
Storage=persistent
SystemMaxUse=4G
SystemKeepFree=4G
SystemMaxFileSize=100M
MaxFileSec=1week
SyncIntervalSec=1
LineMax=1K
ForwardToConsole=yes
MaxLevelConsole=crit
MaxLevelWall=alert
RateLimitIntervalSec=2min
RateLimitBurst=2000
When I try to compress one of the /var/log/journal/*/*.journal files I see a reduction by a factor of 5 while I know that already compressed data cannot be compressed by another compressor, so these files seem to be uncompressed.
How can I get systemd-journald to compress my journal ?
How can I setup an internal SATA SSD such that it boots an Ubuntu installer ISO image ? This would be much faster than using an USB stick.
The naive approach to dd the image file to a disk partition and then setup grub to chainload this partition does not work. Why not ? Which is the key feature for booting an ISO image that a thumb drive has but an internal drive misses ?
My private package repository verifies OK in Ubuntu 14 LTS but fails verification in Ubuntu 18 LTS.
I failed to find the difference in the Ubuntu releases that causes the differerent behavior.
# Hostname, User, Password, Directory, Distribution, Component and Signature are my
# private values in the following code snippets:
apt-get update
Err:2 http://Hostname/Directory Distribution InRelease
The following signatures were invalid: Signature
apt configuration:
cat /etc/apt/sources.list.d/Distribution.list
deb [arch=amd64] http://User:Password@Hostname/Directory/ Distribution Component
Downloading the InRelease file and verifying its signature manually succeeds (same result on Ubuntu 14 and Ubuntu 18):
wget --server-response -O- http://User:Password@Hostname/Directory/dists/Distribution/InRelease > ./InRelease
gpg --verify --keyring /etc/apt/trusted.gpg.d/Distribution.gpg ./InRelease
gpg: Signature made ...
gpg: using RSA key ...
gpg: Good signature from "..." [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: SameSignatureAsInTheAptGetOutputAbove
How can I debug this to the root cause ?
How can I check whether I installed any Universe or Multiverse packages which are, according to /etc/apt/sources.list, "ENTIRELY UNSUPPORTED by the Ubuntu team" ?
What I'm looking for is a command line for Ubuntu 18 LTS server (no GUI) to list installed packages by componenent, including installed packages that are not available from apt-get (not part of the archives configured in /etc/apt/sources.list).
aptitude versions '?name(.)' lists the available packages and their installation status, but does not output their source component, nor does apt-cache.
apt-get install galera-3 mysql-server is successful and creates /usr/lib/galera/libgalera_smm.so, but show status like 'wsrep%' returns nothing.
When I put wsrep_provider=/usr/lib/galera/libgalera_smm.so into my mysql configuration, service start mysql fails with unknown variable 'wsrep_provider=/usr/lib/galera/libgalera_smm.so'.
When I used Galera several years before in Ubuntu 14 LTS, I had to install a galera enabled mysql binary from an external source, but with the availability of the galera-3 package in the Ubuntu 18 repositories I expected that to have changed. Am I wrong ? Or how can I use the galera-3 package correctly ?
Edit: In Ubuntu 14, there was a package percona-xtradb-cluster-galera-2.x, but Ubuntu 18 misses such a package.
apt-cache search percona-xtradb-cluster-galera returns galera-3 and percona-galera-3 because they do both break percona-xtradb-cluster-galera-3.x accordng to the package descriptions, but there is no such package in the Ubuntu 18 repositories.
https://wiki.debian.org/Teams/MySQL/FAQ does not mention Galera.
In the default configuration of Ubuntu 18 LTS server, pressing the V key in less calls the nano editor instead of vi while none of the environment variables $LESSEDIT, $VISUAL or $EDITOR are set.
I was able to restore the correct behavior as documented in man less with update-alternatives --set editor /usr/bin/vim.basic but this proves less executes editor instead of vi.
Is this a documentation bug (Ubuntu behavior intentionally differing from default upstream less behavior) or a bug in less or is it my fault (did I miss something) ?
In former LTS releases, the logger -s command just printed the text to stderr:
Ubuntu 14 LTS (package bsdutils, current version 1:2.20.1-5.1ubuntu20.9) and
Ubuntu 12 LTS (package bsdutils, current version 1:2.20.1-1ubuntu3.1):
logger -s -t test text
test: text
But in the current LTS release, it prepends some strange text:
Ubuntu 16 LTS (package bsdutils, current version 1:2.27.1-6ubuntu3.3):
logger -s -t test text
<13>Aug 24 12:19:04 test: text
I understand that there has been a date prepended in the new version.
But what does <13> mean ?
(The syslog itself does not contain that <13> string.)
Edit: Bonus question: How can I get rid of that ?
How can I trick apt-get to believe that a dependency of an about to be installed package is already installed, so that the referencing package can be installed without installing the dependency ?
Do I have to edit /var/lib/dpkg/status ?
In my real-world case I want to install nagios without having to install mailx and postfix.
I made a shell script /usr/local/bin/mailx that uses msmtp to send mail remotely and linked that to /usr/bin/mailx using update-alternatives.
So I don't need and don't want a local mail infrastructure installed, but nagios3-common depends on bsd-mailx | mailx.
apt-get --force-yes install nagios3-common does not help, neither does defining a negative priority for *mail* packages in /etc/apt/preferences.