[NewsPoster]

Over the period of time since iTunes 12.2 was released, MacNN has been receiving spotty reports of iTunes library corruptions. We've begun preliminary testing on the root cause, and a final determination or possible workaround is some time away -- however, w do have solid data pointing to iTunes corrupting libraries hosted over an OS X network share periodically. More problematically, iTunes libraries accessed over an SMB share from either a Windows-based computer or network attached storage (NAS) device are frequently damaged by some iTunes process.

We've implemented a test library of 400GB of iTunes-stored music and assorted video files. The files are a mix of stuff we've encoded, as well as iTunes store purchases. One library is stored within the normal iTunes-copied hierarchy, another in a custom folder. For the former library, we ensure iTunes copies files to the library upon addition, and with the latter, that setting is disabled.

Our test platforms are a 2010 Mac mini running OS X 10.7, and a 2013 Mac mini Running OS X 10.10.4, along with a Drobo 5D, Synology RackStation RS 214, Lenovo Iomega IS2, and a Rosewill RSV-S8 NAS device. The iTunes host machine is a 2013 i7 Mac mini running OS X 10.10.4. Given current personal events, the iTunes host machine is accessed by Apple Remote Access, but we believe that this doesn't introduce any variables to the testing.

The copy process to the various serving platforms is a Finder copy. Following copy, and a successful checksum comparison, we pointed iTunes 12.1.2 at the library, and waited six hours. In every case, with or without iTunes Match enabled, we didn't see any corruption exhibited, as demonstrated by a checksum evaluation.

We then upgraded iTunes to 12.2 on the host machine, and repeated the iTunes library connections. The locally-stored libraries showed (and continue to show) no corruption issues, with or without iTunes Match. However, the libraries on the Drobo, Synology, and Lenovo NAS devices started gradually corrupting themselves, starting with video files moving around with no pattern discernible at this time. The Rosewill is still running correctly, but we're mindful, and continuing to monitor.

We then turned off iTunes on the Mac mini test platforms, and mounted the libraries on our accessing machine. Following a successful mount, we pointed the iTunes library at the network share. Once again, both Mac mini libraries gradually corrupted themselves, after running fine with local storage for more than eight hours.

Summary

The wide-spread nature of the corruption across a network share suggests that something involved with the iTunes update is the culprit, and not the NAS device hardware itself. While we're not done with our testing -- and are expanding it to Windows versions of iTunes, more hardware, and additional NAS device vendors including Apple Time Capsules and Airport Extreme base stations of various vintages with attached storage -- we feel that our initial findings are important enough to disseminate now.

The bottom line: at this time, MacNN does not recommend storing iTunes libraries in any other location than on a local drive -- internal or external doesn't seem to matter, as long as the content is stored on the same machine as the iTunes application that uses the files as its library. We're not sure of the method of corruption, and we'll be examining closer exactly what happens as time allows.

[Insaneboy]

Great... though I have not seen anything yet on my set up sharing via airdisk from an airport extreme. Actual files are on the airdisk and the iTunes Library is on the local drive.

[Mike Wuerthele]

Yeah, that kind of setup is our next run at the problem.

"additional NAS device vendors including Apple Time Capsules and Airport Extreme base stations of various vintages with attached storage"

[ChrisJ60]

I have observed problems with 12.2 with an 'all local' setup. Luckily I was using a smaller test version of my library so no harm was done. My library has never had iTunes Match enabled but what I observed was that after I enabled iCloud Music Library in 12.2 iTunes would randomly modify some metadata elements for some tracks in my library *and* in the media files on disk (which are *not* stored in the iTunes media folder). The modifications seem to be random and 'destructive' rather than a case of adding missing data. I consider this to be a massive bug and until it is fixed I cannot risk enabling iCloud Music Library in my main iTunes Library since I cannot risk the integrity of the ~14,000 tracks therein which are shared with the rest of my family. I sure hope Apple are paying attention to these issues.

[ericdano]

I haven't seen any corruption yet. Is it the actual files (mp3s/aacs) that get corrupt or the iTunes library file? This article is not clear on exactly what is getting messed up.

I have all the music/video files on a NAS, and the actual iTunes library is locally on my machine. Why would you even store it on a NAS? It gets written to constantly by iTunes, and as your library grows, so does the iTunes .itl file. Plus the XML is constantly being written to, and mine is 400 megs now.....

Could MacNN clarify exactly what they are doing? I haven't seen any issues yet.

[Mike Wuerthele]

Ericdano: The files are intact and play fine, but sometimes have altered metadata. The ITL file is getting badly broken, with files being moved hither and yon.

A single user will see an issue, or not. We have the advantage of being told there's a problem, and the resources to line up multiple testing platforms to see if we can reproduce the problem. Why somebody would store an entire iTunes folder on a NAS isn't up to me, really, and I don't think its a great idea, but it is a thing that people are doing and have done.

ChrisJ60: Just because we haven't tested or seen a problem yet with an all-local solution doesn't mean that there isn't one. The vast majority of our testing focus at first is about the network-stored library situation, because that's the "flaming data" we got in the first place. We'll get there, assuming Apple doesn't patch something first.

My PERSONAL library is fine, and untouched, and is stored locally, so no data point there.



For everyone: this is a very early report. We don't know why its happening, or what the exact mechanism is yet. We know its happening, which is the entire point of this very early article in the process. We thought we'd share before somebody else had to get flaming data.

[aMackUzer]

I have an 83 GB iTunes library on a Thunderbolt drive that's shared via AFP from a client 10.8.5 system. This is only used by 2 different client 10.8.5 systems (not simultaneously) and has always been reliable. After updating to 12.2 and hearing about the corruption issues, I checked and, sure 'nuff, it's grossly corrupted ... which explains why, all of a sudden, various different songs will get updated every time I sync my iPhone -- even though there's been no changes to the iTunes music library. Given the dozens of hours I've put into ensuring all the artwork is valid, etc., it's nice to know I have a backup (actually 2 different kinds of backups).

It's a shame how many issues there are with Apple's updates in the past couple of years (which is why I'm still on 10.8.5). As a Mac user since about 1984, it seems like they're really losing it when it comes to software quality. Apple's stuff no longer "just works!" (and, for the most part, it actually used to do that).

[panjandrum]

@aMackUzer: In regards to your last paragraph; I've been doing mostly-Apple-Specific support since the Mac Plus era, and with the single exception of the System 7.5 era (in which Macs became so crash-tastically unstable they were very nearly unusable, and during which time people held onto their machines that could still run 7.1), and while I keep trying to look on the bright-side and try to find the good in the updates and revisions, that's become increasingly difficult. There is very little doubt that Apple has very much lost their way in terms of software quality and UI design. I hear something like 95% complaints from users now. It's simply non-stop. People who have installed every Apple update or upgrade for years are now afraid to touch them. It's really a great big mess. The latest round of complaints have been about Photos and iTunes, because the vast majority of people I work have feeling ranging from "mild-dislike" to "downright hate" of the changes these have brought. It's a real shame to have to watch this happening. (Primary discussion point this weekend among my family members, who have long been iPhone users, is whether or not to jump to Android? Why? The new iTunes, which every single one of us absolutely hates. Cluttered, hard to use, icons now so tiny and so subtle that any of us over 30 can't tell what they are. It's an exercise in frustration now to use what was once a great, simple, functional app. and is not just a bloated nasty platform for promoting paid Apple content in one form or another at the expense of anything resembling a good Apple user-experience.)

[Mike Wuerthele]

Jump to Android, because they think that iOS Music is unfriendly?

Oh lord, if your family is anything like mine good luck with them over on that side of the fence...

[Spheric Harlot]

Originally Posted by aMackUzer 

I have an 83 GB iTunes library on a Thunderbolt drive that's shared via AFP from a client 10.8.5 system. This is only used by 2 different client 10.8.5 systems (not simultaneously) and has always been reliable. After updating to 12.2 and hearing about the corruption issues, I checked and, sure 'nuff, it's grossly corrupted ... which explains why, all of a sudden, various different songs will get updated every time I sync my iPhone -- even though there's been no changes to the iTunes music library. Given the dozens of hours I've put into ensuring all the artwork is valid, etc., it's nice to know I have a backup (actually 2 different kinds of backups).

It's a shame how many issues there are with Apple's updates in the past couple of years (which is why I'm still on 10.8.5). As a Mac user since about 1984, it seems like they're really losing it when it comes to software quality. Apple's stuff no longer "just works!" (and, for the most part, it actually used to do that).

iTunes is SO much better than it used to be. Seriously.

iTunes used to just willy-nilly delete albums clean off the hard drive at random - a friend ripped "Cydonia" by The Orb from CD no less than three times because iTunes kept deleting it, and another lost quite a bit of work because iTunes deleted stuff he'd painstakingly ripped from vinyl before he had it backed up, and I lost hundreds of songs (including a complete discography) over years.

And then there was that iTunes installer that completely wiped any attached external drive that happened to have a "space" in its partition name...

The only issues I'm seeing are
1.) re-indexing of the same 3,605 tracks for gapless playback every. Single. Time. I. Add. A. New. Song. To. The. ****ing. Library. and
2.) random hangs when editing metadata.

Other than that, I'm pretty happy. Even syncing with my iPhone seems to be working fine, now (after years of complete pain-in-the-ass).

[panjandrum]

Just a quick note that this is not just happening on libraries on shared network volumes. In my case it happened (upon installation of 12.2, no "Apple Music" involved) apparently because I store my iTunes collection on a separate (internal) volume. Lost songs, lost artists, lost TV shows. You name it. Luckily, I always make a manual clone of my OS right before any major update, and then keep that clone until the next major updates (a separate partition is for nightly clones) allowing me to easily revert my OS and apps weeks or months at a time. I should be able to revert to 10.10.3 tonight and hopefully all will be well. Otherwise I'm looking at, potentially, 20+ hours of work rebuilding my playlists and all of my painstakingly compiled custom metadata. My experience is diametrically opposed to Spheric's, which just goes to show you that there are a ton of variables. I have used, my clients have used, and my family has used iTunes pretty much since the moment it existed, and this is the first time I've seen major data-loss issues outside of gross user error. Occasional minor issues? Yes, of course, but whole-sale destruction like this? No.

[panjandrum]

Actually, I just gave that a try. Booting from a clone 10.10.3 drive with iTunes 12.1.2.27 resolved the issue. So, hopefully, a restore from Time Machine, Carbon Copy, or whatever a user happen sto use will fix the situation for others as well. As reported, the files are all still right there where they belong, and as far as I can tell iTunes 12.2 is not deleting them; it's just "forgetting" that they exist.

[Mike Wuerthele]

We are seeing SOME local metadata mangling and forgotten files in our testing, and we're trying to narrow it down to more than "OH GOD iTUNES."

[gbshuler]

I have been keeping my 1TB Tunes library quarantined due to an assertion by this article that my precious library could be corrupted by iTunes 12.2. I look forward to a followup article on iTunes 12.2.2. I would love to move on with my iLife. Thank you for the work you had to do to find this issue.

[Mike Wuerthele]

Yeah, we're working on it. Hopefully some results this weekend.

[Stereo666]

Hi there, I'm writing because this seems to be the only article in the web that deals about the itues and NAS issues...and these I still have, even after latest update and not using cloud or apple Music or match.
I'm running the latest iTunes and OS X on an 2014 Imac, ITunes library on the mac, just the Music on a Synology NAS (Raid 1) and most parts of my library got coruppted. A lot of CD ripped Songs etc.
in the Album view it Shows the Songs, after clicking on them, the doesn't Play or disappear from the Album or a different song starts. So a lot of work from the last years got damaged. I've done backups but this was not the solution to do a restore by just 1 click. so I thought the latest update has solved the issues...I spend 3 days and nights so set up a fresh iTunes, with new library, let iTunes orgnize still the Folders etc. and I thought it would be fine after that. Now yesterday, after I've added some more Songs to ITunes, it starts again and a lot of files got lost / corrupt / not working...I could believe it. did any of you still have issues with latest ITunes and NAS or are your Problems gone after the latest update? As mentioned, I've nerver used match, apple Music or cloud Service...
Best

[Mike Wuerthele]

We do have a follow-up. The new version is better, but not perfect still.

https://www.macnn.com/articles/15/08...re.yet.130044/