Generate Certificate Signing Request (CSR) in Linux
openssl req -new -newkey rsa:2048 -nodes -keyout domain.key -out domain.csr
Replace domain with your domain. domain.csr is what is used by your certificate authority to generate your certificate. domain.key will be used by your web server in conjunction with your certificate.
Monitor or watch an rsync process
strace -e open $(ps -o lwp= -LC rsync | sed 's/^/-p/')
or to see what files the process has opened.
lsof -ad3-999 -c rsync?
E-mail Spoofing and Prevention
TL;DR: No, Sender Policy Framework (SPF) won't fix all your spoofing problems and DKIM by itself will prevent nothing.
Expand Logical volume in Linux LVM
LVM makes it easy to resize volumes in Linux. This can be done without unmounting drives or requiring a restart.
First determine the free space of the group volume.
vgdisplay
Determine the path to the logical volume.
lvdisplay
Expand the logical volume into the group volume. You can specify a size (M for Megabytes, G for Gigabytes, T for Terabytes) …
lvextend -L+19G /dev/ubuntu-vg/ubuntu-lv
or you can expand the logical volume into the remaining free space.
lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv
You will get a success message similar to the screenshot below after the task is completed.
Resize the partition to use the newly expanded logical volume
resize2fs /dev/ubuntu-vg/ubuntu-lv
