NAS migration and iTunes .. ugh

I recently moved our family’s personal storage from a ~14 year old QNAP TS-219P NAS to a new Synology DS224+ NAS, with roughly 2x the storage.

The data migration went pretty smoothly, after a couple of false starts.

I tried a “restore from USB drive” approach first. After all, both NAS types can back up to ext4 filesystems, so it should read OK, right? Unfortunately these copies take a looong time to complete, and the web UI provides no measure of progress to give confidence that it’s working.

Instead, I used ssh access to the new NAS. Each share on the old NAS is directly mounted by the new one.

map_vols.sh:

#!/usr/bin/env bash
for d in fred wilma barney pebbles
do
  mkdir -p /mnt/oldnas/$d
  sudo mount -t cifs -o vers=3.0,user=fred,password=redacted,iocharset=utf8 //192.168.0.4/$d /mnt/oldnas/$d
done

rsync proved a reliable and repeatable means of moving the data across. It was also possible to exclude junk files from the copying process.

moveit.sh:

#!/usr/bin/env bash

cd /volume1/$1
rsync -va --exclude "Temporary Items" --exclude "Network Trash Folder" --exclude "\$RECYCLE.BIN" /mnt/oldnas/$1 /volume1/

moveit.sh takes an argument, allowing each share to be moved individually. It can be run repeatedly to move any new data that has arisen since the copy was started. This allowed a “gradual catchup” strategy, with the old NAS continuing as the primary storage while I did lots of testing of the new NAS.

File ownership

The first “gotcha” was that rsync marks the copied files as owned by root, i.e. the current logged-in user with sudo permissions.

It was therefore necessary to change file ownership afterwards for each share, e.g.

cd /volume1/barney
sudo chown -R Barney:users *

This process completed quickly on the new, more powerful NAS.

Windows clients

Each of the Windows 10 client machines uses a NAS share as their primary area for “My Documents”, “My Pictures” etc. This is set using the Windows Explore, R-click / Properties / File Location dialog. This went smoothly for the majority of applications, with two exceptions: iTunes and Paint Shop Pro 9.

iTunes (ugh)

After migration, iTunes could see some, but not all of the music library files! This was a pain, with thousands of songs and multiple playlists. Several of our shares had over 80GB of separately curated music files.

A bit of digging using the “File info” option in iTunes shows that the app remembers the full UNC path to each media file, instead of using relative paths. Ugh! That would explain why it can’t see all files.

If iTunes can’t find the file, it show the notorious ! warning and Original music file could not be found error. iTunes will offer to try and find the file for you, but this is an arduous task for more than a few files, and you can’t see how many files you will need to fix, i.e. you can’t find the needles in the haystack.

Frankly this whole area is a can of worms. iTunes keeps its library in a proprietary binary-format file, named iTunes Library.itl, in the Music/iTunes directory. The similarly named .xml file in that folder is there only to give you false hope; it’s the .itl file that iTunes reads and uses.

I found an .itl data editor out there but this seemed risky.

In the end, I abandoned library patch-up work, and did:

  • a complete fresh rsync of the Music directory, including the iTunes library files, then
  • renamed the new NAS to have the exact same UNC path (network name) as the old one. This means you also have to rename the old one first, if you want both to be reachable on the network at the same time.
  • For good measure, shut down and restart all client machines, to ensure they are using the new NAS.

Once done, iTunes can see all its files exactly where it expects them to be.

Getting music onto a device

Partly unsuccessful syncs between iTunes and iPhone meant the device was in a somewhat confused state. The solution was quite easy:

  • Delete all songs from the phone. This can be done in a single operation from Settings / iPhone Storage / Music menu. Swipe left and use the red “-” next to “All Songs” - no need to delete the app itself.

  • In the Windows iTunes app, under Edit / Preferences / Devices, there’s a “reset sync history” option.

I found this enabled the library to sync across to the phone again, although it took a couple of tries to get every file across.

Paint Shop Pro 9

This ancient, yet useful app was also complaining on startup, until I switched the new NAS name to be the same as the old; then it worked OK again.