I use a secondary monitor for my notebook since quite a while. Usually I have to open the system settings window to trigger the automatic resolution setting, but today nothing worked. Restarting, (un-)plugging the power, and changing to another monitor didn't help. I knew that my monitor accepts 1920x1080 pixels. With gtf, one can get some default settings:
$ gtf 1920 1080 60
# 1920x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 172.80 MHz
Modeline "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync
xrandr shows the existing monitors and modes:
$ xrandr
Screen 0: minimum 320 x 200, current 2390 x 768, maximum 32767 x 32767
eDP1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 277mm x 156mm
1366x768 60.0*+
1360x768 59.8 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP2 connected 1024x768+1366+0 (normal left inverted right x axis y axis) 0mm x 0mm
1024x768 60.0*
800x600 60.3 56.2
848x480 60.0
640x480 59.9
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
So the corresponding monitor is on DP2. I added the "new" mode by copy-pasting the output from gtf above and activated it for DP2:
$xrandr --newmode "1920x1080_60" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync
$xrandr --addmode DP2 1920x1080_60
$xrandr --output DP2 --mode 1920x1080_60
Voilà, it works.
Kategorie: "Arbeit"
My aim was to play a bit with Ceph to get familiar with the object store. Setting up Ceph is not very easy if something is different from the example in the docs. I don't want to use a whole block device for OSD for example.
I used the docker image https://hub.docker.com/r/ceph/demo/ for that. I installed and started it:
docker pull ceph/demo
docker run -d --net=host -v /etc/ceph:/etc/ceph -e MON_IP=192.168.0.20 -e CEPH_PUBLIC_NETWORK=192.168.0.0/24 ceph/demo
MON_IP has to be the own host's IP and CEPH_PUBLIC_NETWORK the corresponding own network. docker ps didn't show a running container afterwards, so I deleted the container again with docker rm CONTAINER-ID and restarted it without the -d. It showed that my harddisk space was not sufficient, so I added mon data avail crit = 1 to /etc/ceph.conf. docker run CONTAINER-ID worked now; docker ps shows the running container.
I tried to connect to the object store with the Rados Java binding. The import in the examples of the Ceph docs was not quite correct. The corrected version is:
import com.ceph.rados.Rados;
import com.ceph.rados.exceptions.RadosException;
import java.io.File;
public class CephClientTest {
public static void main(String args[]) {
try {
Rados cluster = new Rados("admin");
System.out.println("Created cluster handle.");
File f = new File("/etc/ceph/ceph.conf");
cluster.confReadFile(f);
System.out.println("Read the configuration file.");
cluster.connect();
System.out.println("Connected to the cluster.");
} catch (RadosException e) {
System.out.println(e.getMessage() + ": " + e.getReturnValue());
}
}
}
The first output was
Ceph cluster; ENOENT: No such file or directory (-2)
This was related to the permissions of /etc/ceph/ceph.client.admin.keyring. After adding read permissions to it for other users the connection could be established successfully.
I tried to configure an NTP server within a closed network without internet connection and make many clients synchronize with it (server and clients all on Ubuntu 16.04). Recipe:
- Install ntp on all nodes (ntpdate is not needed and should either be deinstalled or at least not be started)
On the server: remove external NTP servers and make NTP use the local time. My /etc/ntp.conf only contains:
server 127.127.1.0 fudge 127.127.1.0 stratum 9
service ntp restart; ntpq -p should give something like
remote refid st t when poll reach delay offset jitter ============================================================================== *LOCAL(0) .LOCL. 9 l 4 64 377 0.000 0.000 0.000
On the clients: My /etc/ntp.conf only contains:
server NTP-SERVER iburst prefer
service ntp restart; ntpq -p should give something like
remote refid st t when poll reach delay offset jitter ============================================================================== NTP-SERVER .INIT. 16 u 31 64 0 0.000 0.000 0.000
I changed the hosting of my B2Evo blog to SSL. The only necessary configuration change was the $baseurl in conf/_basic_config.php. But there remained an issue with mixed content. Images of posts were still rendered by http, because the image links are hard-coded in the database. The following query helped:
UPDATE evo_items__item set post_content = REPLACE(post_content, 'http://www.fabianfier.de', 'https://www.fabianfier.de') where post_content LIKE '%http://www.fabianfier.de%';
#tar cfvz xyz.tar.gz xyz tar (child): xyz.tar.gz: Cannot open: Disk quota exceeded tar (child): Error is not recoverable: exiting now
HAHA: This machine pretends to use roughly twice as much inodes as the datatype long AND it says it has 500k free inodes:
# df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/vzfs 18446744069909905553 18446744069415334917 494570636 100% /
#rm -rf xyz
Minutes(!) later:
#df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/vzfs 750000 45285 704715 7% /