Basically the date format in Thunderbird follows the system locale – in a terminal type ‘locale’ and the LANG entry should be something like en_GB – if it’s en_US, that’s why it’s displaying the date in the bizarre US format which is MM/DD/YYYY rather than DD/MM/YYYY

To rectify this problem:

1. locale -a
2. vim /etc/locale.gen
3. uncomment:
en_GB.UTF-8 UTF-8
4. comment out:
en_US.UTF-8 UTF-8
5. locale-gen
6. localedef --list-archive OR localectl list-locales
7. vim /etc/locale.conf
LANG=en_US.UTF-8

To make locale changes immediate:

8. unset LANG
9. source /etc/profile.d/locale.sh

I come across this weird problem in RHEL.

It turns out something in /etc/sysconfig/network-scripts/ifcfg-xxx wasn’t right.

Please make sure everything including UUID matches with the actual device.

user1,user2 ALL=(root) NOPASSWD:ALL

With mount –bind, a directory tree exists in two (or more) places in the directory hierarchy. This can cause a number of problems. Backups and other file copies will pick all copies. It becomes difficult to specify that you want to copy a filesystem: you’ll end up copying the bind-mounted files twice. Searches with find, grep -r, locate, etc., will traverse all the copies, and so on.

You will not gain any “increased functionality and compatibility” with bind mounts. They look like any other directory, which most of the time is not desirable behaviour. For example, Samba exposes symbolic links as directories by default; there is nothing to gain with using a bind mount. On the other hand, bind mounts can be useful to expose directory hierarchies over NFS.

You won’t have any performance issues with bind mounts. What you’ll have is administration headaches. Bind mounts have their uses, such as making a directory tree accessible from a chroot, or exposing a directory hidden by a mount point (this is usually a transient use while a directory structure is being remodelled). Don’t use them if you don’t have a need.

Only root can manipulate bind mounts. They can’t be moved by ordinary means; they lock their location and the ancestor directories.

Generally speaking, if you pass a symbolic link to a command, the command acts on the link itself if it operates on files, and on the target of the link if it operates on file contents. This goes for directories too. This is usually the right thing. Some commands have options to treat symbolic links differently, for example ls -L, cp -d, rsync -l. Whatever you’re trying to do, it’s far more likely that symlinks are the right tool, than bind mounts being the right tool.

it’s worth noting that some utilities might consider a bind-mounted directory to be a separate file system. This may have performance or functionality implications if the program can no longer assume that the same inode number refers to the same file (which it doesn’t, if they are on different file systems), a move cannot be optimized as link-at-target-then-unlink-source, etc.

Author: Gilles

Dirty script to show times in different places in the world

echo -n -e "World Times:\n\tTokyo\t\t"; TZ=":Asia/Tokyo" date | cut -d " " -f4; echo -n -e "\tShanghai\t"; TZ=":Asia/Shanghai" date | cut -d" " -f4;echo -n -e "\tMoscow\t\t"; TZ=":Europe/Moscow" date | cut -d" " -f4;echo -n -e "\tRome\t\t"; TZ=":Europe/Rome" date | cut -d" " -f4;echo -n -e "\tLondon\t\t"; TZ=":Europe/London" date | cut -d" " -f4;echo -n -e "\tNew York\t"; TZ=":America/New_York" date | cut -d" " -f4;echo -n -e "\tLos Angeles\t"; TZ=":America/Los_Angeles" date | cut -d" " -f4

find your preferred places in /usr/share/zoneinfo
then place the script in your .bashrc

I was looking into this alternative file system but despite its numerous features for desktop use EXT4 is sufficient.

ln -sf /usr/share/zoneinfo/Europe/London /etc/localtime
and don’t forget to install ntp and start+enable ntpd service

Quick way to setup swap

fallocate -l 4G /swapfile
ls -lh /swapfile
sudo chmod 600 /swapfile
ls -lh /swapfile
mkswap /swapfile
swapon /swapfile
free -m

vim /etc/fstab
At the bottom of the file, you need to add a line that will tell the operating system to automatically use the file you created:
/swapfile none swap sw 0 0