Ceci est une ancienne révision du document !
Q When I try to update my system, I get this error message:
Failed to fetch http://ppa.launchpad.net/kile/stable/ubuntu/dists/vivid/main/binary-amd64/Packages 404 Not Found
A (Thanks to claracc in the Ubuntu Forums) You have obtained the correct response since the aforementioned ppas are not in the pointed address. You can go to software updater and in the “other software” tab, disable these ppas. Reload sources and it is fixed.
Q I'm planning to upgrade from 12.04 to 14.04. What should I back up?
A (Thanks to mastablasta in the Ubuntu Forums) You can make an image of the whole system (clone), or back up just individual folders. I would mostly back up just the data from my home folder for the upgrade. Then, before doing the upgrade, I first try a live session to ensure that all works as it should.
Q Is there a command that I can use to get my power supply data?
A There is no command to query the model number, wattage rating, etc. if that is what you're asking for.
You may be able to check the voltage levels with sensors if your motherboard supports it. They're not always accurate and correctly labelled though. Install lm-sensors, then:
sudo sensors-detect
You only need to run this command once and not every time you want to see sensors.
sensors
Q This morning, I was notified of a software update in 14.04. After applying the update and rebooting, I cannot sign into my system. Enter my password, get the spinning wheel and Nada. Locks up tighter than a drum after about 8 seconds. A total freeze.
A (Thanks to Howefield in the Ubuntu Forums) In the short term, try booting into a previous kernel. If you don't get a grub screen at boot up, press the shift key after switching the machine on and press the advanced options button and choose the previously working kernel.
A buggy kernel was uploaded to ‘-proposed’ – a repository not enabled by default, so only those willing and able, with a higher tolerance to breakage, would/should be affected.
Top questions at Askubuntu
* Is there a software for visual display of disk space? http://goo.gl/XZa99g
* Is it possible to run a Windows .msi installer? http://goo.gl/SrYYmx
* find vs. locate http://goo.gl/IgXpNQ
* When is it necessary to reboot an Ubuntu system? http://goo.gl/NLKG3Q
* Timestamp, year 2038 problem for 64-bit Ubuntu system http://goo.gl/NRqaPl
* What's the best way to write an Ubuntu ISO image on a USB stick? http://goo.gl/o9H3k2
* How to secure my laptop so that hacking by physical access is not possible? http://goo.gl/SggQ74
* Disk slowly filling up but no visible file size changes http://goo.gl/acohCU
* How to execute a specific command on opening a terminal http://goo.gl/6iVa7T
Tips and Techniques
Private folder sharing
Last month I commented about the difficulties I had in setting up a server with numerous shared folders, with each one available to only a single user. I think the problem is solved.
Here are more specifics: the folders are on a drive in a USB 3.0 external dock. They are used as the target for Macrium Reflect image backups of Windows systems; a single 4 TB drive can hold image backups of all the workstations in the organization.
The key to making it work was to put an entry in /etc/fstab to mount the external drive at boot time. If you are interested, Google will reveal lots of good information about fstab. In the specific case, a new drive will be used from time to time, to allow off-site backup. The command “sudo blkid” is useful for setting up and modifying the fstab entry.
The computer is running Xubuntu, which includes the program “users and groups”. For each computer to be backed up, I added the user on the server, with the same password as on their Windows system. I also needed to set up the password in Samba. For user jean, I entered the command:
sudo smbpasswd -a jean
Then I responded to the prompts with appropriate passwords.
Then I created a folder for each user on the external drive. The last set of commands:
sudo nano /etc/samba/smb.conf
Add something along these lines:
[jean] path = /home/administrator/shares/jean available = yes read only = no browseable = yes valid users = jean administrator public = no writeable = yes directory mask = 0750
(save and exit)
Then:
sudo service smbd restart
testparm
And the server part is done.