I'm making a custom bootable USB flash drive with a persistent partition. Formatting the partition as ext2 obviously makes the filesystem very sensitive to improper unmounting. I remember a while back that Ubuntu (and other distributions) had problems when Flash memory was formatted as ext3/4, writing data so frequently that the flash drives died very quickly.
Have these problems now been resolved? Is there any reason to not use a journalled filesystem when formatting a USB flash drive?
I'm trying to create a fresh ISO image for use on a USB stick. I've partitioned my USB stick into 2 partitions, one vfat and one ext4. The vfat partition has the ISO and GRUB2 installed to it, such that GRUB2 boots the ISO.
The ext4 partition has the volume label casper-rw and is used as the persistent data store for the Live USB. I've modified the grub.cfg such that I get two options at boot, one to boot the ISO in persistent mode and one to boot normally.
However, when booting in "normal" mode, the casper-rw partition is mounted as a normal drive and changes made in persistent mode don't stay.
What I would like is the casper-rw partition to be mounted overlaid on the / filesystem, but when I ask Ubuntu to boot normally (i.e., without the persistent option in GRUB2), I'd like that partition to be mounted read-only so that changes made in the persistent mode persist.
What is the best way to achieve this?
I have a GUI application that needs to call a daemon (written in Python) with superuser privileges. I would like to do this without prompting the user for a password.
Since the daemon is a script, I can't set the SUID bit directly. I could write a C wrapper for this, but I'd rather not reinvent the wheel, especially when a mistake on my part could lead to the system's security being severely compromised.
What I'd normally do in this situation is to add a line in /etc/sudoers that allows users to execute the daemon as root without a password, using the NOPASSWD directive. This works fine from the command line. However, when I do this from the GUI, a pkexec dialog pops up asking for the user's password. It seems that on Ubuntu, calls to sudo from the GUI are somehow being intercepted by pkexec.
Is there a clean way around this? I'd really rather not have to deal with the hassles of a setuid script.
I have a script that creates a file in cron.d and puts some jobs in it. Cron seems to not execute these jobs at all, since the program it runs is set to log all executions. The file inside cron.d looks something like this:
SHELL=/bin/sh
PATH=/sbin:/bin:/usr/sbin:/usr/bin
*/1 * * * * root /usr/bin/python /home/myname/some_script.py --switch1
2 21 * * 4 root /usr/bin/python /home/myname/some_script.py --switch2 --switch3
Neither of these jobs is executed and I can't find anything in grep CRON /var/log/syslog.
The scripts work fine when executed normally. Any ideas?
EDIT: Adding the line */1 * * * * root echo "something" >> /tmp/something works fine.
Note: Though AskUbuntu won't show it, the file does have a trailing newline.
When using wget in a script to download some files from Google Docs, the name of the file is not preserved. For example:
wget 'http://spreadsheets.google.com/pub?key=pyj6tScZqmEfbZyl0qjbiRQ&output=xls'
saves the file as pub?key=pyj6tScZqmEfbZyl0qjbiRQ instead of indicatorhivestimatedprevalence15-49.xls, which is what I get if I click on the link in a browser. Is there any way to enforce this "browser-like" behaviour in wget?
When I'm reading ebooks, I find it quite useful to blank out everything except the reader. On the Mac, I use Backdrop to achieve this. What this app does is blank out everything (wallpaper, desktop icons, etc) apart from any on-screen windows. Is there a program that does this for Ubuntu?
I accidentally screwed up the groups for my main user by doing sudo usermod -G blah instead of sudo usermod -a -G blah. On realising this, I immediately rebooted into single user mode and added the groups adm dialout cdrom floppy fuse to the user's account. Everything seemed to be more or less back to normal and I could sudo as usual on the command line. However, the authentication dialog box that shows up in the GUI has stopped working for nearly all programs. The dialog shows up as normal, but will not accept the password. gksudo firefox from the command-line seems to work, as does Synaptic, leading me to believe that I'm merely missing a group that the other Ubuntu configuration/admin apps check for. Any solutions would be much appreciated.