linux备份系统盘

免安装linux 系统 可以用来, 急救

https://www.linuxliteos.com/download.php

查看 进程 io 情况

# 查看 进程 id
ps -aux | grep rsync | grep -v grep

# 查看 进程  打开的 文件 描述符 
lsof -p   id

# 查看 进程 io 性能
iostat  -xm 1

将 块设备 压缩至 文件

To save space, you can compress data produced by dd with gzip, e.g.:

dd if=/dev/hdb | gzip -c  > /image.img.gz
You can restore your disk with:

gunzip -c /image.img.gz | dd of=/dev/hdb
To save even more space, defragment the drive/partition you wish to clone beforehand (if appropriate), then zero-out all the remaining unused space, making it easier for gzip to compress:

mkdir /mnt/hdb
mount /dev/hdb /mnt/hdb
dd if=/dev/zero of=/mnt/hdb/zero
Wait a bit, dd will eventually fail with a "disk full" message, then:

rm /mnt/hdb/zero
umount /mnt/hdb
dd if=/dev/hdb | gzip -c  > /image.img.gz
Also, you can get a dd process running in the background to report status by sending it a signal with the kill command, e.g.:

dd if=/dev/hdb of=/image.img &
kill -SIGUSR1 1234
Check your system - the above command is for Linux, OSX and BSD dd commands differ in the signals they accept (OSX uses SIGINFO - you can press Ctrl+T to report the status).

dd if=/dev/hdb  of=/dev/sda