If you need to terminate not active SSH session please use keys sequence:
Continue reading “How to kill SSH session / SSH hangout”
How to create partitions and format them under Linux (Centos 7)
When you add new disk first you need to identify device path.
Please type:
# fdisk -l
and find path to your new disk, e.g.
/dev/sdb
Continue reading “How to create partitions and format them under Linux (Centos 7)”
How to add new disk in VMware / ESXi / vCenter without rebooting
If you want to add new HDD to existing Linux virtual machine like CentOS 7 / RHEL 7 you must:
First add new disk in preferences of virtual machine.
Click Edit preferences of virtual machine. On tab Hardware click Add button and fill proper preferences.
When you save data new hardware should appear on hardware list.
Now login to your virtual machine and execute:
# fdisk -l
You should see all previous mounted hardware.
Continue reading “How to add new disk in VMware / ESXi / vCenter without rebooting”
How to mount devices or shares without rebooting system / reload fstab
When you make new entries in /etc/fstab or lost connection to network (e.g. samba) share it is possible to remount all disconnected devices.
To do so you need to execute:
Continue reading “How to mount devices or shares without rebooting system / reload fstab”
How to deal with high IO in linux
If you are dealing with high IO wait on linux machine then you must detect which application causing this.
First use
# top
This will show list of current running applications.
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How to make email copy of all sent messages (auto BCC) in Postfix
If you want to make copy of all messages sent through email accout then create file /etc/postfix/sender_bcc with contents:
#emails from #BCC to
from@domain.com bcc@domain.com
Then edit /postfix/main.cf file and add at the end of file
Continue reading “How to make email copy of all sent messages (auto BCC) in Postfix”
How to disable yum repository
Sometimes we struggle with slow or broken repository.
First make sure that the yum-fastestmirror plugin is enabled.
Then clear cache with:
Continue reading “How to disable yum repository”
How to generate self signed wildcard ssl certificate
First genarate RSA private key.
Use 2048 bit or even better 4096 bit key
openssl genrsa 2048 > host.key
Now generate signing request.
enter *.domain.com for the Common Name
openssl req -new -x509 -nodes -sha256 -days 3650 -key host.key > host.crt
Continue reading “How to generate self signed wildcard ssl certificate”