You need to first install NTFS-3G package to access NTFS on Debian. NTFS-3g depends on libntfs and fuse. Using the following shall install NTFS-3g on the system:
apt install ntfs-3g -y
Once done, now you can mount ntfs using the following command:
mount -t ntfs /dev/sdb2 /mnt
In this case, sdb2 is the ntfs partition, and we are mounting this to /mnt directory.
If you are trying to mount a Windows 10/11 partition, you might end up having a read only NTFS file system. The reason is Windows 10/11 partition doesn’t fully shutdown on shutdown command, instead it hibernates the system. To properly shutdown the system, remember to shutdown the system with ‘SHIFT’ + SHUTDOWN.
There are times, you may end up with the following error, when you are trying to install R1Soft hcp module or the kernel module in Ubuntu based servers:
kernel module installer failed. (0) - R1Soft - Could not find a suitable hcpdriver module for your system - Ubuntu
Full error could be like the following when you call for –get-module
root@hisab:/lib/modules/r1soft# serverbackup-setup --get-module
Building header archive ...
outfile = /tmp/headers881407773
headers = /usr/src/linux-headers-5.4.0-128-generic
Session ID: 379634599
Waiting to upload...
Uploading file...
Waiting in build queue...
Failed to get suitable module for this system: Failed to build module: No builders found.
Get module failed.
Falling back to old get-module ...
Checking if module needs updated
Checking for binary module
Waiting /
No binary module found
Gathering kernel information
Gathering kernel information complete.
Creating kernel headers package
Checking '/tmp/r1soft-cki.1667140819' for kernel headers
Found headers in '/tmp/r1soft-cki.1667140819'
Compressing...
Starting module build...
Building / kernel module installer failed. (0):
Internal error encountered. Please contact support
Request ID: (75ca382d-5a0e-4161-8c70-8b136a6b1330)
http://www.r1soft.com/distros/index.php?uuid=75ca382d-5a0e-4161-8c70-8b136a6b1330
To solve this error, you may get the built kernel module for Ubuntu based on it’s distribution in their repository. The link to the repository would be as following:
http://beta.r1soft.com/modules/
Now, if you are using Ubuntu 20.04, then the module would be available under the folder: Ubuntu_2004_x64
In my case, it was Ubuntu 20.04. Next stop, is to find the kernel version. You may get it from the following command:
root@hisab:~# uname -a
Linux hisab.skincafe.co 5.4.0-128-generic #144-Ubuntu SMP Tue Sep 20 11:00:04 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
root@hisab:~#
Kernel number to note in our case, would be ‘5.4.0-128’. Now search for this inside the link:
http://beta.r1soft.com/modules/Ubuntu_2004_x64/
You should find a match, like for my case it was the following link:
Next stop, is to go to the r1soft module folder and load the module. You may do so like the following:
cd /lib/modules/r1soft
wget http://beta.r1soft.com/modules/Ubuntu_2004_x64/hcpdriver-cki-5.4.0-128-generic.209.ko
Now, all you need, is to restart r1soft. Remember to stop and star the agent instead of direct restart.
service cdp-agent stop
service cdp-agent start
This should be able to load the HCP module now. You may verify this by typing:
root@hisab:~# hcp --list
Idera Hot Copy 6.16.4 build 117 (http://www.r1soft.com)
Documentation http://wiki.r1soft.com
Forums http://forum.r1soft.com
Thank you for using Hot Copy!
Idera makes the only Continuous Data Protection software for Linux.
No Hot Copy sessions are currently running.
root@hisab:~#
Sometimes, you may want to run a screen command in a remote server. That makes it necessary to run the command inside the screen session while starting it.
How to start a screen session and run a command in one line
# screen -d -m sh -c "yourcommand"
From the man page of Screen:
-d -m : Start screen in “detached” mode. This creates a new session but doesn’t attach to it. This is useful for system startup scripts.
Exim provides a quick way to check the total number of mails in the queue. This is done using the exim -bpc Although, this is not the same for postfix. Postfix doesn’t come with an easy way to do that.
How to Check Total Number of Mails in Postfix Queue
A quick tip on what I use to check the postfix queue number is the following command:
If you are using Centos 7 or RHEL 7 or any of it’s variant, you are probably using ‘Firewalld’ by default. Although, if you are a iptables fan like me, who likes it’s simplicity and manipulative nature instead of a full form firewall, then you probably have disabled firewalld from your CentOS 7 instance and using iptables. There are couple of servers, where I use runtime iptables rules for postrouting and masquerading. These rules are dynamically generated by my scripts instead of the sysconfig file under:
/etc/sysconfig/iptables
This file is generated upon running the iptables save command:
service iptables save
which I rarely do so.
Error Details
Which is why, I don’t have a /etc/sysconfig/iptables file in those servers and a common error I see while restarting iptables in those system is the following:
# systemctl restart iptables.service
Assertion failed on job for iptables.service.
How to Fix The Error
The error appears because you don’t have any rule in /etc/sysconfig/iptables or the file doesn’t exist either. You can ignore the error as iptables would still run. To eradicate the error, simply make sure you have some iptables rules loaded on your system using the status command:
iptables -S
And then, run:
service iptables save
Once done, restarting iptables shouldn’t show the error any longer.
Sometimes, you will see the error thrown in dmesg or /var/log/messages are mentioned in dm-number format, while you manage the disk using lvm logical volume name. This is because lvm logical volumes are designed through kernel device mapper technique and kernel recognizes volumes using dm numbers. There is a tool to list all the device mappers used for block devices under Linux. Simply type the following to list the maps:
# lsblk
It shall show something like the following:
There you can see the dm number for each lvm volume is listed under first bracket. For example the swap in this server is created with LVM with the name vg_iof442/swap and has the dm-1 mapping.
