LVM Data Recovery
LVM (short for Logical Volume Manager) is a complex partitioning scheme from Linux.
LVM is used in various Linux servers and in many, if not all, modern NASes, used as home or SOHO storage, like Buffalo and NetGear.
In most cases NAS devices use LVM to combine md-raid arrays (which can be of different levels) into JBOD.
Actually, LVM itself fails quite rarely, most likely you deal with a failure either of a filesystem stored on the LVM volume or md components forming the LVM volume.
If LVM metadata is damaged usually LVM recovery software is capable of parsing LVM metadata to reconstruct an LVM partition.
How to recover data from a failed LVM partition with ReclaiMe
ReclaiMe File Recovery can read LVM metadata and supports more or less all combinations – LVM created over physical disks, over MBR or GPT partitions,
and over md-raid arrays.
To recover data from LVM you need:
- Extract all the disks from the failed NAS and then connect them directly to a PC.
- Download ReclaiMe File Recovery.
- Install the tool as you regularly do with any other software.
- Launch ReclaiMe File Recovery and select the device partitioned with LVM under "Linux LVM volumes" section for the analysis.
Pay attention that when recovering LVM you need to select the device in "Linux LVM volumes" section rather than RAIDs from “Linux md-raid volumes”.
Md-raid volumes are the components LVM is made of.
- Within 3% of scan ReclaiMe File Recovery displays the recovered data.
Check the files and folders and if you are satisfied with the result, click the Save button and start copying data; otherwise, wait to see if more data is recovered.
If there is no LVM volume in ReclaiMe, most likely either md or LVM metadata is severely damaged.
In this case first you need to recover array configuration with ReclaiMe Free RAID Recovery
and only then to recover data as described above.
This is only possible when there is a single md array on the disk set. If the disks are of the same size and
were never replaced with larger disks,
then the recovery is possible. If at some point the disks were replaced with the larger ones to expand capacity of a NAS,
you probably need a heavier software.
For more technical details go to www.data.recovery.training.
Additionally, if you want to look at metadata or even feel able to correct md or LVM metadata,
you can use disk editor of ReclaiMe Pro software
which can read both text metadata and binary LVM metadata.
All the above is a safe but tedious and not free way to recover a failed LVM volume;
there are another methods to "reanimate" LVM partition like those described on this page.
However, we do not recommend in-place repair because if something goes wrong, more severe damage is possible.