I’m trying to make an emergency recovery disk with Mondorescue to:
- Restore my server in case of hardware (or severe software) failure.
- Make an “identical” server setup for debugging and staging. My original image was lost when my laptop died, during setting up this server. Then I had to do it again from scratch in a hurry..
I’m running CentOS 6.4 and installed the system and data storage on top of a volume group to be able to make snapshots. The VG was made with LVM2 and I’m not exactly familiar with the details but from what I’ve gathered LVM2 uses
/dev/mapper as a layer between the block devices and the OS that can be used for disk encryption etc. (or something like that..).
Mondorescue does not like LVM2. After successfully making a restore image I can’t recover my system because it can’t restore the VG’s. The Mondorescue FAQ tells me:
Now if you encounter a problem with it, it might be due to the fact that older versions of mondorescue didn’t support correctly the usage of /dev/mapper/vg*. So you needed to adapt your /etc/fstab in order to make mondorescue happy, as here:
/dev/mapper/vg_system-lv_var /usr ext3 defaults 0 2
/dev/mapper/vg_system-lv_usr /var ext3 defaults 0 2
/dev/vg_system/lv_usr /usr ext3 defaults 0 2
/dev/vg_system/lv_var /var ext3 defaults 0 2
My questions are..
- Is this safe to do on my production server or might it not reboot after this modification?
- Does it matter if you reference to
/dev/mapper/vg_xxx, will it work?
- Or.. If I shouldn’t / it doesn’t work, does anyone know a working solution?
Thanks a lot!
The two device paths you give are equivalent, as far as Linux is concerned; they always point to the correct LV.
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