Resending all deferred emails via Plesk interface
Go to Tools & Settings > Scheduled Tasks > Add Task.
/usr/sbin/postsuper -r ALL
Click Run Now.
Missing vmail Folders .Sent, .Trash, .Drafts, .Junk, and Other
- Missing Sent, Trash, Drafts, Junk, and Other Folders
Solution: Check whether the dot files are hidden. Make the dot files to show.
Horde
- Click on the Folder Actions option.
- Choose the Rebuild Folder List option.
- Then choose the Show All Mailboxes option.
Roundcube
- Go to Settings.
- Click Folders.
- Re-subscribe to each folder by clicking the check box.
Windows Mail
- Click IMAP Folders.
- In the Show/Hide IMAP Folders dialog box, select a folder.
- Click Show.
Thunderbird
- In the Folder pane, look for IMAP mail and right-click on it.
- Go to Settings, click on Server Settings, then select Advanced.
- Remove the checkmark on Show only Subscribed folders.
- Click OK.
Microsoft Outlook Express
- Under Folders on the left side of the screen, select the inbox for your email (NOT the one under Local Folders).
- Click the Tools menu, then select IMAP Folders.
- Select the desired folder(s).
- Click Show.
- Click OK.
How to Add and Remove Swap Space on Ubuntu 20.04
Generally, the size of the swap file depends on how much RAM your system has:
- Less than 2 GB RAM – 2 times the amount of RAM.
- 2 to 8 GB RAM – the same size as the amount of RAM.
- More than 8 GB RAM – at least 4 GB of Swap.
Only root or user with sudo privileges can activate the swap file.
1). First, create a file that will be used as swap:
sudo fallocate -l 2G /swapfile
2). Set the file permissions to 600 to prevent regular users to write and read the file:
sudo chmod 600 /swapfile
3. Create a Linux swap area on the file:
sudo mkswap /swapfile
4). Activate the swap file by running the following command:
sudo swapon /swapfile
5). To make the change permanent open the /etc/fstab file:
sudo vi /etc/fstab
and paste the following line:
/swapfile swap swap defaults 0 0
6). Verify that the swap is active by using either the swapon or the free command, as shown below:
sudo swapon --show
and
sudo free -h
Adjusting the Swappiness Value
On Ubuntu, the default swappiness value is set to 60. You can check the current value by typing the following command:
cat /proc/sys/vm/swappiness
While the swappiness value of 60 is OK for most Linux systems, for production servers, you may need to set a lower value.
sudo sysctl vm.swappiness=10
To make this parameter persistent across reboots, append the following line to the /etc/sysctl.conf file:
vm.swappiness=10
Removing a Swap File
To deactivate and delete the swap file, follow these steps:
1). First, deactivate the swap space:
sudo swapoff -v /swapfile
2). Next, remove the swap file entry from the /etc/fstab file.
/swapfile swap swap defaults 0 0
3). Finally, remove the actual swapfile file using the rm command:
sudo rm /swapfile
Xauthority does not exist
- /usr/bin/xauth: file /root/.Xauthority does not exist
Solution
Go into the sshd_config file
vi /etc/ssh/sshd_config
Search and remove the # sign at the beginning of the 3 lines
X11Forwarding yes X11DisplayOffset 10 X11UseLocalhost yes
Then restart sshd
systemctl restart sshd
Exit and login again. You will not get the error.
Or
Create n new file: touch ~/.Xauthority
Log out and login in again.
How to Zip and Unzip Files and Directories in Linux
- Zip Command
- How to zip files
- How to zip directory / directories
- How to Test if a ZIP File is Valid
- How to unzip a zip
- How to unzip a zip to a different directory
zip Command
zip OPTIONS ARCHIVE_NAME FILES
To zip one or more files
zip archive-name.zip filename1 filename2 filename3
Create a zip archive of a directory including the content of sub-directories. The -r option allows to traverse the whole directory structure recursively:
To zip one directory including sub-directories.
zip -r archive-name.zip directory-name
To add multiple files and directories in the same archive
zip -r archive-name.zip directory-name1 directory-name2 file1 file2
How to Test if a ZIP File is Valid
unzip -t archive-name.zip
This is useful if you think the zipped file has been damaged or corrupted.
To extract a zip file in the same directory
unzip archive-name.zip
To extract a zip file to a different directory
unzip -d archive-name.zip /path-to-unzip
The –d switch tells the system to put the unzipped files somewhere else.
To overwrite unzipped files/folders
unzip -o archive-name.zip