zeldor.biz

Linux, programming and more

Increase number of disk mounts

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Many home users power off their home computers and servers when they are not being used. Each of you had already this problem, you need very quickly your PC or server and you press the power-ON button and now you can wait.
File system Check!
The check seems to take forever, you can go and make coffee, and the system boot won’t resume until the check is over. [Read more…]

Create LVM Snapshot

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I want to show you how to create a LVM snapshot on the fly, before you install some nasty updates.

I have my KVM virtual machine (/dev/vg0/Webserver) and want to upgrade it, before I go on, I want to create a LVM snapshot. In worst case it can change back to this state.

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lvcreate -L 5000 -s -n "7.9_wheezy" /dev/vg0/devel.drobot.de

– L 5000 is the size in MB
-s flag is to create a snapshot
-n 7.9_wheezy is the name of new logical volume

If something goes wrong, go back to previously created snapshot:

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lvchange -a n /dev/vg0/devel.drobot.de
lvconvert --merge /dev/vg0/7.9_wheezy
lvchange -a y /dev/vg0/devel.drobot.de

Attention!
If you delete your origin volume your snapshot will be automatically deleted!