An odd situation occurred today and all it started with an update to iOS that could not be installed because there was insufficient storage on my iPad. It resulted in a search to discover where the storage had disappeared to and the answer was surprising and if you think you know how to solve this, you are probably wrong. I don’t know whether it was a bug or feature, but it was weird.

I have a 16GB iPad and it is becoming increasingly difficult to manage because 16GB does not go very far these days. Apps are growing in size and I’m always low on memory.

There was a notification this morning about a new update to iOS and version 7.1.2 was available. OK, that’s no problem I thought, tap Settings, Software Update and install it. The problem is that Software Update reported that it could not install the update because it requires at least 1.5GB of free storage.

iPad iOS update

There is a Usage Settings link here, but you can get a storage usage report at any time by going to Settings, General, Usage. Here’s what it said:

iPad storage usage

The Usage report shows that I have 1GB of storage space available and the item using the most storage space on the iPad was Music. It was using 1.5GB of space.

At first sight, this might seem quite ordinary, but the thing is, I have iTunes Match. Go to Settings, iTunes and App Store and there is an on/off switch. It was on.

iPad iTunes Match

The idea of iTunes Match is that all your music is stored in the cloud and not on the device. Firstly, it frees up storage space on the device and secondly, any of your iOS devices, such as an iPhone or iPad, can play the music by streaming it over the internet.

The iPad was using 1.5GB of storage space for music, so I started the Music app to see what music is stored on the device.

iPad Music

A nice feature of iTunes Match is that you can swipe across a music track in the Music app and delete it. The track is deleted from the iPad, but it remains in your music library with a cloud icon on the right, indicating that you can still play it whenever you want because it is store on iCloud. Instead of playing from the iPad storage, it streams over the internet.

Every single track was in the cloud and not one was on the iPad. With no music tracks on the iPad, how come it was using 1.5GB of storage space for music?

I returned to iTunes and App Store in Settings and turned off iTunes Match. I then opened the music app.

iPad Music

It quite rightly said that there was no music. Zero. None. I returned to the iTunes Match switch and turned it back on. My music library was instantly restored and I could play any music again. Returning to Usage showed this:

iTunes storage usage

I now had lots of storage space free. Music does not appear on the top space hogs list, so I have recovered the 1.5GB of space that Music was using. (There’s slightly more space than you might expect because I deleted a couple of unused apps as well, but the missing Music app from the list is the important point.)

Why was Music using 1.5GB of storage space when it is streamed from the cloud using iTunes Match? I think the reason must be because it is caching the music. Every time I played a music track, it must have saved it on the iPad in case I wanted to listen to it again. That would save bandwidth by not having to download it again, but if you have a large music library and you listen to a lot of different tracks, you could end up using a lot of storage space.

I’m guessing that turning off iTunes Match must have cleared the cached music and returned the storage space it was using to the pool. The iOS update could then proceed as normal.

It’s a trick worth remembering when you are short of storage space