The machine that hosts the site(http://blog.foool.net) collapsed some time ago, and this is not the first time that such a breakdown happens. I reinstalled the machine and restored the data, including the database and some ordinary files. The followings are some useful commands that helped me to backup and restore the system.

Disk Info.

df -h

list info. of all file systems. (‘h’ indicates to print the size with the human-readable format )

lsblk

list info. of all block devices.

File info.

du -a / | sort -nr | head -10

list the top 10 largest directories and files.

-a counts all files, not just directories.

-n compare according to string numerical value.

-r reverse the results.

-<num> list only the top <num> items.

du -sh

the storage amount of the current directory.

-s display only a total result

find . -type f -printf "%s %p\n" | sort -nr | head -10

list the top 10 biggest files of the current directory.

Backup & Restore

ssh user@remote "dd if=/dev/sda | gzip -1 -" | dd of=image.gz

Backup disk /dev/sda to a remote compressed image file.

The second – of “gzip -1 -” means reading the input from standard input.

ssh user@ip ‘dd if=/home/user/sdb.img.gz’ | gunzip -1 - | dd of=/dev/sdb

Restore disk /dev/sdb from a remote compressed image file.

sudo rsync -aAXv / –-delete --exclude={/dev/*,/proc/*,/lost+found}  user@ip:path

Backup all files, excluding some specific ones, to remote.

-aAXv (a)archive mode, (A)perserve ACLs, (X)preserve extended attributes, (v)verbose.