CentOS: Error: rpmdb open failed

rm -f /var/lib/rpm/__db*
db_verify /var/lib/rpm/Packages
rpm --rebuilddb
yum clean all

Ubuntu: GRUB Error 17 / OVH

root (hd0,0)
setup (hd0)
kernel /boot/vmlinuz-XXXX root=/dev/vda1
initrd /boot/initrd.img-XXX
boot

OVH KVM resize root parition Centos 7 XFS

lsblk

parted

select /dev/sdb

unit s

print

rm 1

mkpart

Partition type? primary
File system type? xfs
Start? 2048s
End? 100%

print

set 1 boot on

quit

mount /dev/sdb1 /mnt

xfs_growfs -d /mnt

sentora / zpanel change e-mail quota

mysql;
use sentora_postfix;
update mailbox set quota = 3000 where username like "email@domain.com";

atop cheat sheet

Cron

58 23 * * * killall atop
05 0 * * * rm -f /var/log/atop.log
07 0 * * * atop -w /var/log/atop.log 5

To read the log:

# atop -r /var/log/atop.log

Press t to move forward to the next 5 seconds, and press shift+t to move backwards.

To read only a certain time range from the log (b for beginning, e for end):

# atop -r atop.log -b 10:00 -e 11:00

To change the view:

g - Show generic output (default)

m - Show memory related output

s - Show scheduling characteristics

c - Show the command line of the process

how many inodes in directory

find /path -xdev -printf '%h\n' | sort | uniq -c | sort -k 1 -n

MySQL uszkodzona tabela

myisamchk -r -f logowanie.MYI

ansible debian update template

http://pastebin.com/raw/4DiYYvq4

openssh ciphers

Ciphers aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes128-ctr
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,hmac-ripemd160
KexAlgorithms diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1

postfix kasowanie kolejki

postsuper -d ALL

rm -f /var/spool/mqueue/*