I've upgraded two laptops to Ubuntu 20.04 LTS. On one of them pressing Super (aka the Windows Logo key) opens the Activities overview. On the other one it doesn't, and I have to use Super+S, or Alt+F1.
The main difference between the laptops is that one uses Ubuntu on Wayland (where Super works fine), and the other one uses Ubuntu on Xorg (where Super doesn't work).
How do I make Super work on both laptops?
I have an Ubuntu 12.04 server that exports a couple of filesystems over NFS.
server$ cat /etc/exports
/home 192.168.42.0/255.255.255.0(rw,anonuid=65534,anongid=65534,async,no_subtree_check)
/stuff 192.168.42.0/255.255.255.0(rw,anonuid=65534,anongid=65534,async,no_subtree_check)
/stuff 192.168.99.0/255.255.255.0(ro,anonuid=65534,anongid=65534,async,no_subtree_check)
I also have a client that mounts them:
client$ cat /etc/fstab
...
server:/home /home nfs hard,intr,rsize=8192,wsize=8192,_netdev 0 0
server:/stuff /server/stuff nfs hard,intr,rsize=8192,wsize=8192,_netdev 0 0
The client's IP is in the 192.168.42.x range. It was running Ubuntu 10.04 until yesterday. NFS worked fine, more or less (sometimes it wouldn't automount on boot, but I had a cron script to detect and fix that).
I upgraded the client to Ubuntu 12.04 yesterday and rebooted. NFS continued to work fine.
I upgraded the client to Ubuntu 14.04 today and rebooted. Now NFS is mounted but all file ownership information is mapped to nobody:4294967294:
client$ ls -ld /home/weblate
drwxr-xr-x 5 nobody 4294967294 4096 Jan 29 2014 weblate
Why is that and what do I need to do to make file ownership work again?
I would like to use LVM2's built-in RAID support (lvconvert -m1 --type raid1 vgname/lvname) on my Ubuntu 12.04 LTS server. Unfortunately this feature appeared in LVM2 2.02.89 (assuming I've read the changelog correctly), while Ubuntu 12.04 has LVM2 2.02.66.
What are my options? Is there a backport of newer LVM2 somewhere? Will a newer lvm2 package require a newer kernel than the one in 12.04, or are these features managed in userspace somehow?
I've an OpenERP server running on one of my servers. It's started by a traditional /etc/init.d/ script. It uses a PostgreSQL database and needs a manual restart every time PostgreSQL is restarted.
Every time Ubuntu releases a security update for PostgreSQL, my OpenERP server becomes non-functional until I ssh to the server and manually run sudo /etc/init.d/my-openerp restart. I usually forget to do that after I do the sudo apt-get upgrade.
Can I configure upstart to do that for me, every time postgresql is restarted by apt?
I've a typical small office server with two hard disks configured for RAID-1 (mirroring). Each disk has several partitions: one for swap, the others paired in several /dev/mdX arrays.
Every couple of years one of the disks dies and is replaced. The replacement typically goes something like this:
# copy partition table from the remaining good disk to the empty replacement disk
# (instead of /dev/good_disk and /dev/new_disk I use /dev/sda and /dev/sdb, as appropriate)
sfdisk -d /dev/good_disk | sfdisk /dev/new_disk
# install boot loader
grub-install /dev/new_disk
# create swap partition reusing the same UUID, so I don't need to edit /etc/fstab
mkswap /dev/new_disk1 -U xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
# hot-add the new partitions to my RAID arrays
mdadm /dev/md0 -a /dev/new_disk2
mdadm /dev/md1 -a /dev/new_disk5
mdadm /dev/md2 -a /dev/new_disk6
mdadm /dev/md3 -a /dev/new_disk7
mdadm /dev/md4 -a /dev/new_disk8
The disks were originally partitioned with cfdisk back in 2009, and so the partition table is aligned traditionally to cylinder boundaries (255 heads * 63 sectors). This is not the optimum configuration for new 4K-sector drives.
My question is: how can I create a set of partitions for the new disk and ensure they're properly aligned, and have correct sizes for my RAID arrays (rounding up is acceptable, I suppose, but rounding down is definitely not)?
I use Mutt for gpg-signed email. With previous versions of Ubuntu I could tell Mutt to use gnome-gpg, which would ask for my GPG passphrase with a GUI window and then store it my GNOME keyring for 24 hours or until logout, whichever came first. However gnome-gpg was removed from universe in Ubuntu 11.10. Is there a replacement?
Every now and then I'd like to play with a fresh minimal install of Ubuntu (to test sysadminish scripts, application install instructions, package dependency lists etc.).
I'd like to have a tool as simple to use as testdrive: pick a version (say, 'maverick'), run a command, get a shell in a new virtual machine.
I'd like that shell to be in the current terminal, rather than a new GUI window that testdrive uses. Setting up the new VM to accept SSH logins with my ssh public key is fine.
I'd like the VM to have network access out of the box; NAT to a virtual network interface is fine.
Why a VM? Chroots don't really cut it: installing, say, Apache in a chroot would fail because it would try to listen on port 80, which is already taken. Containers might work, though, if there are any that are supported by standard Ubuntu kernels.
Vagrant is a tool to build and manage virtual machines for developers. It has a getting started on Ubuntu guide that contains iffy-looking suggestions like
$ sudo ln -s /usr/bin/ruby1.8 /usr/bin/ruby # wtf???
or installing RubyGems from source rather than from Ubuntu packages, and then using gem install to install vagrant itself.
I'm not feeling comfortable just following those instructions. Is there perhaps a PPA? Are there, perhaps, alternative tools that are packaged for Ubuntu?
How can I list all packages I've installed from a particular repository?
How can I list all installed packages that are not available from the main Ubuntu archives, and also see which repositories they came from? (If I knew the answer to this question, I could grep that list for a particular PPA name to find out the answer to my first question.)
There are various system-wide debug tools (sysprof, oprofile, systemtap) that need debug symbols. Getting debug symbols for userspace applications is easy: https://wiki.ubuntu.com/DebuggingProgramCrash
The ddebs repository also contains linux-image-$(uname -r)-dbgsym packages, but even if I install it, sysprof continues to show me unhelpful "in kernel" without detailed information. Where can I get debug symbols that sysprof can use?
The systemtap package has a Suggests: linux-debug-2.6. Apt-cache search fails to find anything called linux-debug-2.6. Is it available somewhere? Or is this an unproductive dead-end?
Incidentally, oprofile can use the debug symbols from the above-mentioned dbgsym package, but not out of the box -- it wants
/lib/modules/$(uname -r)/build/vmlinux, and I have to tell it to use use /usr/lib/debug/boot/vmlinux-$(uname -r)-generic. But oprofile lacks a nice GUI, so I'd prefer sysprof.
So, how can I convince sysprof to show me what's happening in the kernel?
Ubuntu 10.04 has only two supported Python versions 2.6 and 3.1. Developers often need more, to test that their Python code works on 2.7, 2.5 (and maybe even 2.4 and older ones). What's the best way to install those Python versions side-by-side on a lucid system?
Is it Felix Krull's PPA, which I'm currently using?
Incidentally, some important packages aren't available in those non-standard Pythons from the deadsnakes PPA:
When you install certain updates (e.g. a new kernel) in Ubuntu Desktop, you get an indication that a reboot is required (in Lucid, the logout icon turns red).
How can I check, from the command line, whether an Ubuntu server requires a reboot?
I could grep for 'System restart required' in /etc/motd, but I'd like a solution that's more elegant. Also, I want a solution that works in older releases, e.g. Hardy (8.04 LTS).