# Administration **URL:** https://linux-tips.com/c/administration/18.md [Latest](https://linux-tips.com/latest.md) · [Categories](https://linux-tips.com/categories.md) --- ## [About the Administration category](https://linux-tips.com/t/about-the-administration-category/133)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 0
Topics related with administration --- ## [Disabling UPS beep under Linux](https://linux-tips.com/t/disabling-ups-beep-under-linux/592)
**Author:** [@Greg](https://linux-tips.com/u/Greg)\ **Replies:** 3\ **Last updated:** [July 2, 2026, 7:28pm UTC](https://linux-tips.com/t/disabling-ups-beep-under-linux/592 "2026-07-02T19:28:10Z")
If you have one of the ups devices which doesn’t have an easy way to disable annoying beep sounds when the main power gets down, you can turn off the beep behaviour in most cases, even if the seller says that “there is n… --- ## [Disabling reverse dns lookups in ssh](https://linux-tips.com/t/disabling-reverse-dns-lookups-in-ssh/222)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 6\ **Last updated:** [January 18, 2023, 4:39pm UTC](https://linux-tips.com/t/disabling-reverse-dns-lookups-in-ssh/222 "2023-01-18T16:39:22Z")
Sometimes it is very annoying to wait ten's of seconds to finish remote ssh server's reverse dns lookup procedure. It can be disabled on the server side but this process has a few tricks. First of all, you have to make… --- ## [Booting from an ISO image using qemu](https://linux-tips.com/t/booting-from-an-iso-image-using-qemu/136)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 9\ **Last updated:** [January 28, 2021, 8:03pm UTC](https://linux-tips.com/t/booting-from-an-iso-image-using-qemu/136 "2021-01-28T20:03:52Z")
Qemu has two operating mode named full system emulation and user mode emulation. If you want to simulate whole system not just the cpu (like a PC) you need to use full system emulation mode. Newer distributions have se… --- ## [How to force fsck to run on next boot](https://linux-tips.com/t/how-to-force-fsck-to-run-on-next-boot/256)
**Author:** [@Debuser](https://linux-tips.com/u/Debuser)\ **Replies:** 1\ **Last updated:** [December 26, 2020, 10:11am UTC](https://linux-tips.com/t/how-to-force-fsck-to-run-on-next-boot/256 "2020-12-26T10:11:17Z")
It is not possible to run fsck on actively working filesystem. You have to run it before the filesystem mounted as read-write mode. If you don't have any chance to unmount the filesystem which you want to run fsck on i… --- ## [Couldn't start virtual machines after Proxmox 4.1 upgrade](https://linux-tips.com/t/couldnt-start-virtual-machines-after-proxmox-4-1-upgrade/317)
**Author:** [@Greg](https://linux-tips.com/u/Greg)\ **Replies:** 2\ **Last updated:** [May 16, 2020, 11:27am UTC](https://linux-tips.com/t/couldnt-start-virtual-machines-after-proxmox-4-1-upgrade/317 "2020-05-16T11:27:26Z")
We have a running Proxmox 4.0 setup on 2 Debian Jessie server with a few container machines. Recently we decided to upgrade both of the servers and Proxmox components with: $ sudo apt-get update $ sudo apt-get dist-up… --- ## [Memory problems on QtWebEngine build](https://linux-tips.com/t/memory-problems-on-qtwebengine-build/761)
**Author:** [@Debuser](https://linux-tips.com/u/Debuser)\ **Replies:** 0\ **Last updated:** [July 26, 2019, 8:47am UTC](https://linux-tips.com/t/memory-problems-on-qtwebengine-build/761 "2019-07-26T08:47:28Z")
QtWebEngine uses its own copy of ninja build system. As a general rule, build process parallelized by the ninja as number of cpus available + 2 formula. So, if you have a system with 12 core and 16 GB of RAM, it is not … --- ## [Passwordless sudo](https://linux-tips.com/t/passwordless-sudo/150)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 0\ **Last updated:** [August 3, 2015, 12:48pm UTC](https://linux-tips.com/t/passwordless-sudo/150 "2015-08-03T12:48:36Z")
If you want to give permissions to some users who are in a special group (probably sudo) to use sudo without asking password, you can do this simple in two steps: First of all, you must add related users to group sudo. … --- ## [Execute JNLP files in Linux](https://linux-tips.com/t/execute-jnlp-files-in-linux/252)
**Author:** [@Debuser](https://linux-tips.com/u/Debuser)\ **Replies:** 1\ **Last updated:** [May 9, 2019, 2:11pm UTC](https://linux-tips.com/t/execute-jnlp-files-in-linux/252 "2019-05-09T14:11:25Z")
Java Network Launching Protocol (JNLP) files describes how to launch Java Web Start applications. To execute a jnlp file, you need javaws binary which you can install with: $ sudo apt-get install icedtea-netx After … --- ## [Running programs linked against libssl1.0.0 on Debian9](https://linux-tips.com/t/running-programs-linked-against-libssl1-0-0-on-debian9/717)
**Author:** [@Debuser](https://linux-tips.com/u/Debuser)\ **Replies:** 0\ **Last updated:** [January 29, 2019, 7:42pm UTC](https://linux-tips.com/t/running-programs-linked-against-libssl1-0-0-on-debian9/717 "2019-01-29T19:42:52Z")
Debian9 shipped with libssl1.1 and libssl1.0.2 packages. If you’re getting a loader error like this: /usr/lib/x86\_64-linux-gnu/libssl.so.1.0.0: version \`OPENSSL\_1.0.0' not found you can download libssl1.0.0 package fr… --- ## [Gnome tracker-extract takes too much cpu](https://linux-tips.com/t/gnome-tracker-extract-takes-too-much-cpu/713)
**Author:** [@redsector](https://linux-tips.com/u/redsector)\ **Replies:** 0\ **Last updated:** [January 12, 2019, 10:42pm UTC](https://linux-tips.com/t/gnome-tracker-extract-takes-too-much-cpu/713 "2019-01-12T22:42:23Z")
Every gnome users should take this suggestion seriously. I’ve a quiet fast notebook with nvram ssd disk on it. But as you see below, those tracker-extract and their tracker-xxx families of processes works more than 4 ho… --- ## [XFS Filesystem has duplicate UUID problem](https://linux-tips.com/t/xfs-filesystem-has-duplicate-uuid-problem/181)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 6\ **Last updated:** [January 12, 2019, 9:10pm UTC](https://linux-tips.com/t/xfs-filesystem-has-duplicate-uuid-problem/181 "2019-01-12T21:10:58Z")
If you can not mount your XFS partition with classical wrong fs type, bad superblock etc. error and you see a message in kernel logs (dmesg) like that: XFS: Filesystem sdb7 has duplicate UUID - can't mount you can sti… --- ## [Setup openvpn server in Proxmox LXC Container](https://linux-tips.com/t/setup-openvpn-server-in-proxmox-lxc-container/695)
**Author:** [@RaskoX](https://linux-tips.com/u/RaskoX)\ **Replies:** 0\ **Last updated:** [November 9, 2018, 2:30pm UTC](https://linux-tips.com/t/setup-openvpn-server-in-proxmox-lxc-container/695 "2018-11-09T14:30:41Z")
If you try to install openvpn server to an LXC container, you will get following error: ERROR: Cannot open TUN/TAP dev /dev/net/tun: No such file or directory (errno=2) This is related with the design decision of unpri… --- ## [Extending disk size on VirtualBox](https://linux-tips.com/t/extending-disk-size-on-virtualbox/253)
**Author:** [@Debuser](https://linux-tips.com/u/Debuser)\ **Replies:** 1\ **Last updated:** [November 1, 2018, 7:31am UTC](https://linux-tips.com/t/extending-disk-size-on-virtualbox/253 "2018-11-01T07:31:57Z")
Sometimes it is needed to extend the size of the disk which is used by VirtualBox. To do this, you have to extend physical size of the disk image file. For example if you have disk file named WindowsC.vdi with 25 GB of… --- ## [Disable startup sound of MacBook and iMac](https://linux-tips.com/t/disable-startup-sound-of-macbook-and-imac/606)
**Author:** [@DrSlump](https://linux-tips.com/u/DrSlump)\ **Replies:** 1\ **Last updated:** [December 31, 2017, 11:21am UTC](https://linux-tips.com/t/disable-startup-sound-of-macbook-and-imac/606 "2017-12-31T11:21:36Z")
Is there any way to disable startup sound of MacBook and iMac’s from Linux? I saw it is possible through efi variables but when I try to write suggested sysfs variables, I always getting operation not permitted error. --- ## [How can I disable teamviewer daemon](https://linux-tips.com/t/how-can-i-disable-teamviewer-daemon/297)
**Author:** [@Greg](https://linux-tips.com/u/Greg)\ **Replies:** 2\ **Last updated:** [December 1, 2017, 11:11pm UTC](https://linux-tips.com/t/how-can-i-disable-teamviewer-daemon/297 "2017-12-01T23:11:44Z")
Teamviewer daemon automatically starts in Linux. What is the correct way to disable it? --- ## [Using Canon MF43XX UFR II Printers in Linux](https://linux-tips.com/t/using-canon-mf43xx-ufr-ii-printers-in-linux/532)
**Author:** [@sputnik](https://linux-tips.com/u/sputnik)\ **Replies:** 0\ **Last updated:** [July 9, 2017, 6:32pm UTC](https://linux-tips.com/t/using-canon-mf43xx-ufr-ii-printers-in-linux/532 "2017-07-09T18:32:16Z")
Canon MF series (MultiFunction) printers uses a proprietary rendering engine UFR (Ultra Fast Renderer) which has similar functionality to PostScript. If you want to use these printers in Linux (cups), you need to downloa… --- ## [Docker service \[service doesnt reply\]](https://linux-tips.com/t/docker-service-service-doesnt-reply/518)
**Author:** [@Gomes](https://linux-tips.com/u/Gomes)\ **Replies:** 1\ **Last updated:** [June 3, 2017, 8:23am UTC](https://linux-tips.com/t/docker-service-service-doesnt-reply/518 "2017-06-03T08:23:58Z")
Hi. I thanks if anyone helps me! After I create my docker swarm and services, my service is not accessible! See the snapshot below.One strange thing is REPLICAS = 0/1. docker@swarm-master:~$ docker service ls ID … --- ## [Adb device unauthorized problem](https://linux-tips.com/t/adb-device-unauthorized-problem/254)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 0\ **Last updated:** [August 3, 2015, 8:50pm UTC](https://linux-tips.com/t/adb-device-unauthorized-problem/254 "2015-08-03T20:50:55Z")
Sometimes when you want to use adb for debug purpose, you may get a device not authorized error. You should first check output of the following command: $ adb devices -l List of devices attached ???????????? … --- ## [Users with /bin/false shell to login on vsftpd](https://linux-tips.com/t/users-with-bin-false-shell-to-login-on-vsftpd/200)
**Author:** [@demirezen](https://linux-tips.com/u/demirezen)\ **Replies:** 2\ **Last updated:** [August 30, 2016, 10:01am UTC](https://linux-tips.com/t/users-with-bin-false-shell-to-login-on-vsftpd/200 "2016-08-30T10:01:21Z")
With default configuration of vsftpd (vsftpd.conf under /etc) users with no shell or /bin/false shell are not able to login vsftpd ftp server. This is because vsftpd.conf includes such a line to enable pam module: pa… --- ## [Transferring files without ftp or scp](https://linux-tips.com/t/transferring-files-without-ftp-or-scp/359)
**Author:** [@evgind](https://linux-tips.com/u/evgind)\ **Replies:** 0\ **Last updated:** [June 28, 2016, 10:13am UTC](https://linux-tips.com/t/transferring-files-without-ftp-or-scp/359 "2016-06-28T10:13:56Z")
Need to transfer a directory to another server but do not have FTP or SCP access? Well this little trick will help out using the netcat utility. On the destination server run: nc -l -p 1234 | uncompress -c | tar xvfp … --- ## [How to backup and restore bootsector](https://linux-tips.com/t/how-to-backup-and-restore-bootsector/358)
**Author:** [@evgind](https://linux-tips.com/u/evgind)\ **Replies:** 0\ **Last updated:** [June 27, 2016, 12:47pm UTC](https://linux-tips.com/t/how-to-backup-and-restore-bootsector/358 "2016-06-27T12:47:19Z")
Trying to install new O/S with dual-boot is a scary job, it can leave you with a messed up bootsector. To backup first 512 bytes: dd if=/dev/hda of=bootsector.img bs=512 count=1 First 512 bytes on the hdd is known… --- ## [Passwordless ssh setup](https://linux-tips.com/t/passwordless-ssh-setup/165)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 1\ **Last updated:** [February 25, 2016, 3:56pm UTC](https://linux-tips.com/t/passwordless-ssh-setup/165 "2016-02-25T15:56:58Z")
If you want to use passwordless ssh login feature, you should use public key authentication mechanism. To do this, remote server must be configured to enable public key authentication (enabled by default) and you shoul… --- ## [How to remove GPT partition table in Linux](https://linux-tips.com/t/how-to-remove-gpt-partition-table-in-linux/304)
**Author:** [@redsector](https://linux-tips.com/u/redsector)\ **Replies:** 1\ **Last updated:** [November 24, 2015, 11:15am UTC](https://linux-tips.com/t/how-to-remove-gpt-partition-table-in-linux/304 "2015-11-24T11:15:32Z")
I have an USB stick device which has an HFS volume with GPT partition table. I want to write an iso image to the stick with: $ sudo dd if=debian-8.2.0-amd64-CD-1.iso of=/dev/sdb bs=8M Command completed successfully b… --- ## [Disk free results not updated after removing files](https://linux-tips.com/t/disk-free-results-not-updated-after-removing-files/298)
**Author:** [@RaskoX](https://linux-tips.com/u/RaskoX)\ **Replies:** 1\ **Last updated:** [November 15, 2015, 8:54pm UTC](https://linux-tips.com/t/disk-free-results-not-updated-after-removing-files/298 "2015-11-15T20:54:46Z")
We have a web server which has %100 disk usage on some partitions because of the webserver logs. When I delete some of the log files with rm command to free up disk space, nothing changed on output of the df command. … --- ## [Downgrade a package with its dependencies](https://linux-tips.com/t/downgrade-a-package-with-its-dependencies/261)
**Author:** [@tsezer](https://linux-tips.com/u/tsezer)\ **Replies:** 0\ **Last updated:** [August 12, 2015, 6:39pm UTC](https://linux-tips.com/t/downgrade-a-package-with-its-dependencies/261 "2015-08-12T18:39:07Z")
Debian package manager supports installing packages with version numbers. Using this feature, you can downgrade a package to stable version if you install a package from test or unstable repository before. dpkg: Inst… --- ## [Meaning of the message: Clock: inserting leap second 23:59:60 UTC](https://linux-tips.com/t/meaning-of-the-message-clock-inserting-leap-second-23-59-60-utc/257)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 0\ **Last updated:** [August 3, 2015, 8:57pm UTC](https://linux-tips.com/t/meaning-of-the-message-clock-inserting-leap-second-23-59-60-utc/257 "2015-08-03T20:57:39Z")
After June 30, 2015 if you have NTP or PTP time synchronization services installed in your Linux system, you'll see a kernel log like that: Clock: inserting leap second 23:59:60 UTC This is normal because of the extra… --- ## [Simulating hardware reset button in Linux](https://linux-tips.com/t/simulating-hardware-reset-button-in-linux/251)
**Author:** [@demirten](https://linux-tips.com/u/demirten)\ **Replies:** 0\ **Last updated:** [August 3, 2015, 8:38pm UTC](https://linux-tips.com/t/simulating-hardware-reset-button-in-linux/251 "2015-08-03T20:38:10Z")
There are some cases in which you couldn't reboot a Linux system with reboot command or alternatives. If you have this problem and you don't have physical access to server, it is also possible to simulate pressing hardwa… --- ## [Sharing media files over DLNA](https://linux-tips.com/t/sharing-media-files-over-dlna/246)
**Author:** [@tsezer](https://linux-tips.com/u/tsezer)\ **Replies:** 0\ **Last updated:** [August 3, 2015, 8:16pm UTC](https://linux-tips.com/t/sharing-media-files-over-dlna/246 "2015-08-03T20:16:48Z")
Rygel is the one of the most popular DLNA softwares on Linux. It is a home media solution that allows you to easily share audio, video and pictures to other devices. Rygel configuration is very simple except two tricky… --- ## [Your hostname is not set properly errors](https://linux-tips.com/t/your-hostname-is-not-set-properly-errors/242)
**Author:** [@Debuser](https://linux-tips.com/u/Debuser)\ **Replies:** 0\ **Last updated:** [August 3, 2015, 7:49pm UTC](https://linux-tips.com/t/your-hostname-is-not-set-properly-errors/242 "2015-08-03T19:49:39Z")
You may receive this errors on Linux systems in several programs specifically on installation on service setup step. Most common reason for this problem, if your fully qualified domain name does not include any . (dot)… [Next page](https://linux-tips.com/c/administration/18.md?page=1)