I recently had the problem that I wanted to move all my Docker data (in the appdata folder) over the network to an external NAS. But since Plex and Jellyfin consists of a lot of small files depending on the size of the media library, copying took me two days despite 10 Gbit/s.

 

I would like to show you here how I solved the problem by moving these files to a vDisk and thus the transfer is now much faster.

 

Structure

1. Create thin provisioned vDisk
2. Adjust vDisk-Size
3. Remove vDisk
4. Show size
5. Auto-Mount/-Unmount
6. Backup vDisk

 

Create thin provisioned vDisk

1. Create vDisk (.img)

truncate -s 100G /path/vDisk.img

(This creates a .img-File with the maximum size of 100 GiB)

 

2. Create file system

mkfs.xfs /path/vDisk.img

(possible options can be displayed by typing "mkfs" in the console and pressing Tab twice)

 

3. Create Mountpoint

mkdir /mountpoint/

(in my case the mountpoint is /mnt/disks/vm/appdata/plex)

 

4. Mount vDisk

mount -t auto -o loop /path/vDisk.img /mountpoint/

 

5. Adjust permissions

chown nobody:users /mountpoint/

(or wathever group or user you use)

 

6. Move files

Now, you can move/copy your files to this mountpoint (vDisk)

mv /plex_directory/* /mountpoint/

(keep in mind to change the permissions after moving the files)

 

 

Adjust vDisk-Size

1. unmount vDisk

umount /mountpoint/

(with the option -l you can force the unmount)

 

2. adjust vDisk size

truncate -s 200G /path/vDisk.img

(200G is the new size)

e2fsck -f /path/vDisk.img && resizefs /path/vDisk.img

(allocate the new size to the filesystem)

 

Remove vDisk

1. unmount vDisk

umount /mountpoint/

 

2. delete vDisk

rm /path/vDisk.img

 

 

Show size

Maximum size vDisk

du -h --apparent-size /path/vDisk.img

 

Effective disk space used

du -h /path/vDisk.img

 

 

Auto-Mount/-Unmount

You can insert this commands into a Userscript for mounting with the start of the Array or unmount with stop of the Array

(I use this config for my daily use. I haven't notice any serious performance drawbacks. Just make sure the vDisk is mountet before you start the Docker-Container!)

 

 

Backup vDisk

To backup a vDisk we just copy the .img fith the following command:

dd if=srcFile.img of=dstFile.img iflag=direct oflag=direct bs=64K conv=sparse

 

Edited November 24, 20205 yr by balrog
added some infos

On 10/18/2020 at 4:43 PM, balrog said:

You can insert this commands into a Userscript for mounting with the start of the Array or unmount with stop of the Array

is this command: mount -t auto -o loop /path/vDisk.img /mountpoint/

7 hours ago, moonerick said:

is this command: mount -t auto -o loop /path/vDisk.img /mountpoint/

 This is one of them. Here is an example of a full script (mount and unmount):

Mount (0_Mount-vDisks.sh) 

#!/bin/bash
#name=0_Mount-vDisks
#backgroundOnly=true

# Plex
mount -t auto -o loop /mnt/disks/VM/vdisks/PlexMediaServer.img /mnt/disks/VM/appdata/PlexMediaServer/

# VOD
mount -t auto -o loop /mnt/disks/VM/vdisks/vod.img /mnt/disks/VM/appdata/vod/

# Media
mount -t auto -o loop /mnt/disks/VM/vdisks/media.img /mnt/disks/VM/appdata/media/

Unmount (0_Unmount-vDisks.sh)

#!/bin/bash
#name=0_Unmount-vDisks
#backgroundOnly=true

# Plex
umount -l /mnt/disks/VM/appdata/PlexMediaServer/

# VOD
umount -l /mnt/disks/VM/appdata/vod/

# Media
umount -l /mnt/disks/VM/appdata/media/