PSA/Warning - Changing Plex Transcode Directory Wiped 12-15 TB Of My Data

Server Version#: 1.42.1.10060
Player Version#: N/A
OS Version#: Windows 10 Pro 22H2 19045.6216

As the title says.. Two of my drives F:\ and D:\ were nearly completely wiped just by changing the drive letter set for both ‘Transcoder temporary directory’ and ‘Downloads temporary directory’ under Settings>Transcoder.

I’m on up to date Win 10 and Plex Version 1.42.1.10060.

So here’s what happened.. About a week ago I was poking through the Plex settings looking to increase the buffer time for streams. Just so happens that one of those settings is right there along with the transcoding location settings. Well, My F:\ drive was in the red and getting near to full just like I:\ in the photo above. My D:\ drive was just about 1/2 full at the time. (I know, I know, but I haven’t got the money to buy the drives for my NAS build yet)

So, I changed the drive letter from F:\ to D:\ and hit save changes. A few minutes later I opened file explorer for something and noticed both drives were nearly empty. Hoo buddy, that’s a real feeling right there. I haven’t felt panic like that in a very long time.

I immediately shut down plex, qbit, and all of my arr’s so nothing could write to the drives and started researching and recovering what I could onto my external J:\ drive. It wasn’t much and a lot was corrupted. UGH! I was really really hoping it was just some missing pointers or something but they were wiped pretty thoroughly.

I was just able to recreate the issue today actually. I’ve spent the last several days letting qbit reacquire what it can from what I hadn’t manually removed already in the past from it’s list. So just a few hours ago, I thought, ‘to hell w/it. i still don’t KNOW what the issue is. and every damn time i try rewriting any files back onto F:\ they’re automatically deleted within minutes when PMS is running. so, screw it.. let’s try that again.

Welp.. As soon as I hit save changes I was refreshing file explorer over and over and could see the available space increasing each time I refreshed. No other changes on my system whatsoever.

So, I did the only thing I could think of. F:\ was already empty so I created a 10 GB partition on it and pointed the Plex Transcode Settings at it, P:\ as seen in the pic as well.

IDK WTF has caused this on my system, but I sure as ■■■■ urge caution to anyone that reads this. :frowning: no, i didn’t have logging enabled ffs)

So now I’m off to rebuild again. Yay!

If anyone is willing to try and test this, I highly recommend doing it on some spare drives or new partitions with copied data. Otherwise, just DON’T DO IT.

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Can’t see the picture. Imgur is over capacity. Please upload it to the thread if possible. Just drag it into the message window and wait for it to upload.

For the transcode directory, did you just use the root directory of the drive instead of a subdirectory. For example, D:\ instead of D:\transcode (or similar)?

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Uploaded the pic to the forum. Thanks for the tip.

I tried to be as accurate w/my descriptions as I could remember. So yes, I set both of those locations for transcode and download temp directories to F:\ in the first place years ago but then the drive was nearly full. So then I changed it to D:\ and that’s when everything went sideways. When this all happened, I immediately changed it back to F:\ not knowing what else to do at the time. I had already lost most everything on both drives by the time I did. It was like they were being formatted it happened so fast.

I suppose some years ago I changed that to F:\ instead of leaving it how it was b/c I was running out of space on one or both of the old 4 TB drives I used to have installed. I wound up upgrading to two 10 TB drives at the time. And back then, when I originally changed those two settings to my new F:\ drive, nothing like this ever happened. This time, It nuked both drives at the same time.

If I remember right, I’d also set the database backups to another drive as well, b/c my OS drive was running low at the time. And I think I put the transcoding on another separate drive trying to speed things up for streaming back then. This all feels like 10 years ago. Everything’s been running w/out a hitch until now.

And to bring it back up, when I set them to just the drive letter, it created it’s own folders ‘F:\Transcodes>Sessions’

@citizenatlarge ugh that is awful… Very sorry that this happened. Thank you for reporting. We were able to quickly reproduce this issue. The issue looks to be isolated to the Downloads temporary directory setting. So like you reported, once the Downloads temporary directory is set, anything inside that directory is wiped. Setting the root of a drive would then in effect wipe the drive. I’ve created an internal issue for our engineers to investigate. Thank you again for reporting and again very sorry that this happened and the inconvenience this has caused.

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@Atomatth thanks so much for taking the time to test and reproduce the issue. I just really don’t wish something like this to inadvertently happen to anyone else.

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For what it’s worth, one immediate change we made was to our support article covering this setting here.

Before:

After:

Engineers are still reviewing the issue.

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That’s definitely a clearer caution. Ideally, I wouldn’t mind seeing something in the UI description, or some check, function, popup, or something that would either be a strong caution or a confirmation that you’d like to delete said data.. As I’m sure you observed, there was nothing to indicate what was about to happen when clicking save changes.

Thanks again for your help with this and getting people involved that can mitigate this risk moving forward.

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I’d like to clarify a point that I’m not sure is fully clear so far..

I had two drives. F:\ 10TB and D:\ 16TB .. I used F:\ as the transcode thing, but then it got full and I changed the settings to D:\ .. POOF

That change wiped all of the data off of BOTH of the drives.

The only thing I can imagine that happened, is that Plex is wiping the directory upon creation and deletion.. Like some big broom cleaning out an Airbnb b/c it doesn’t want additional charges.. idk.. just saying haha. But, that really happened. It took away EVERYTHING as it came in, and cleared EVERYTHING in it’s wake as it went..

After I’d quickly changed those settings back to F:\ , which was already too late, whatever I put on F:\ would delete itself. I tried through programs, and by just making simple .txt files. Whatever was written to the drive was wiped within minutes, it felt like.. Nothing survived a reboot. The only folder that survived on F:\ was F:\Transcode>Sessions

How is there no size limit to Plex’s greed in this way? Just format it. Just do it. WHAT!?

I’m not sure if this helps? But, the behavior is godly w/out user input. I do not like that at all.

I am also not at all sure if cross posting is allowed, forgive me if it isn’t please, i’m new and a lot is a lot.. but i don’t mind sharing my own content.

this is what brought me here - lack of answers

So I’ve just found this .

I stupidly did set my c drive for the downloads location …. For me I got lucky and it didn’t wipe the drive but it did randomly delete entire folders , luckily nothing I couldn’t restore , I finally found it was Plex using process monitor and saw this

Type: SetDispositionInformationEx, Flags: FILE_DISPOSITION_DELETE, FILE_DISPOSITION_POSIX_SEMANTICS , 0x10

Plex medias sever was the process !! I have backups of the device but damn, it deleted a lot of stuff … I was diagnosing drive failing issues , cache write issues etc. I’m actually kinda relieved it was Plex lol

For me it seemed to be newly created folders and files , I created test folders and files , sometimes they’d stay for hours , then poof gone

I’ll accept its on my putting the root of my C drive, that was a dumbass mistake, i just set it quickly and didnt think about it again.

backups people!

Thinking out loud , probably couldn’t delete my windows folder due to being in use !! Kinda lucky