I would like to make copies of my Virtual Machine .img files to my array in order to quickly recover from an accidental .img deletes. Some of my VM images are partitioned to use 400 GB but are only currently using around 50 GB. I am thinking that creating a RAR backup of the image file would be a pretty good idea to save space. Anyone else have any other ideas that I should consider?

Hmmm, it would appear that the RAR program (to create rar archives) is shareware and will require a licence after 40 days. I suppose in addition to my orginal question I would like to know if unRAID has any sort of built in function to compress files? If not, is there a recommend compression program that is good and free? 

Appears that the tar function is baked in. Never used it before so I might give it a shot.

 

**Notes to myself**

To compress the file as tar.bz2

tar cvfj Windows.img.tar.bz2 /mnt/user/VM\ BACKUP/

 

Uncompress tar.bz2 Archive File

tar -xvf Windows.img.tar.bz2 -C /mnt/vmdisk/mnt/vmdisk/vm_images/

 

Reference Link

You would have to cleanly shut down the vms before you tar and mv right?

Correct, I tried the above but the compression is super slow. I'm probably going to have to look into other options due to the large img sizes.

Well creating tar files was much too slow. I decided to just convert my .img files to .qcow2 which greatly reduced the space. I can then decide later on if I want to convert them back to .img files if I need to put the original image back.

 

qemu-img convert -O qcow2 /mnt/vmdisk-2/vm_images/Windows.img /mnt/user/VM\ BACKUP/Windows.qcow2

 

qemu-img convert -O raw image-converted.qcow2 image-converted-from-qcow2.img