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Linux, programming and more

Progress bar for DD

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I am still searching for a perfect progress bar for DD, I know a dirty trick[*1] – put DD to background an sending “USR1” signal to bring it to show a progress – I hate this solution!

This one is not so dirty, but you have only the done progress and transfer speed.

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dd if=/opt/wap/Backup.tib | pv | ssh -c arcfour id@tower "dd of=/home/id/Backup.tib"
1.94GB 0:01:15 [30.1MB/s] [<=>

Dirty trick:
Only local way!

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dd if=/opt/wap/Backup.tib of=file.img bs=4KB& pid=$!
while true; do kill -USR1 $pid && sleep 1 && clear; done

Accessing data on guest lvm

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for my KVM guests I use only LVM disks, I find it easy to use and administer.
Every time you running out of space you can resize your lvn volume.
Bus some days ago I moved some virtual servers to another physical Dom0(Host) and was a little bit confused – how to move lvm – DD was not the best idea.

There is always another way, here is my:
Very important! Shut-down virtual machine.
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Knock Knock

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SSH is by default very strong, and since a long time without critical bugs. It has strong protection against various hacks and known vulnerabilities. For instance SSH has a password retry wait time of (default) five seconds. This makes the time for brute force attacking an SSH-server very long and not effective. However, sometimes script-kiddies will fork their hacking program making multiple processes of the brute force attack. Sometimes they are able to fork it off upwards of 1000 attempts every 5 seconds. This drastically minimizes the time to crack short passwords.

I think SSH is secure enough, but there is always a way to make it more secure.

Install knock daemon:

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aptitude install knockd

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SSH aliases

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I think you now this problem, you have a lot different hosts with different ssh ports.
It takes to much time to write the full ssh commands and recognize all of your ports:

Easy solution – use aliases:

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vim .ssh/config
# Add this
Host piper
    HostName piper
    User root
    Port 1022
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ssh piper