My torrent client downloads files to internal SSD. When I'm low on storage (often), I remove some torrents from qbittorrent and move files to external HDD. It means I can't seed them anymore.

I want to be able to seed HDD torrents periodically. What workflow can I employ? I can think of:

1. Use 2 different torrent clients. One with "external" torrents only. It will never be launched when external HDD is not plugged in, therefore old torrents will not be marked as "missing files" and will not require verification every now and then;

2. Use single torrent client which can accept CLI commands to start/stop specific torrents. Before detaching external HDD I will run a script to stop all external torrents. I will resume them back again only when HDD is accessible.

Any other ideas?

You can just change the destination through the context menu, qbt will move them and continue seeding.

You could also use the categories function for this purpose.

I can move, but next time when I will launch qbt without external HDD accessible, those torrents will gain error status "Files not found" and will require a long verification process. This is what I'm trying to avoid.

I will check how categories can help managing this, thx

It happens to me every time I forget to mount the second drive, I just close qbittorrent mount the drive and start again, it does the regular check that does every time it launches and all good.

#1 is probably the easiest solution outside of leaving your external drive connect all the time.

"regular check" - do you mean verification? Verification takes a lot of time, verifying 10s of gigs will take a lot of time. What do you forget, stopping torrents?

You don't need to but #1 could be a bit easier if you prefer multiple torrent clients/instances for organization. qBittorrent / Deluge can run multiple instances so you could have like qBittorrent "A" instance pointing to your internal SSD and qBittorrent "B" instance pointing to your external HDD. That's just a quick example but I'm sure Transmission and other torrent clients can do the same.

The only tricky bit with multiple torrent clients is that they'd each need their own incoming connection port if you intend to be fully connectable (port forwarded). That may not be feasible if you're using a VPN that only gives you 1 port forward but otherwise it's doable, depends on your setup.

I mean the one it does every time it starts, when it looks if everything is where it thinks it is. At least when I start it the progress bars are white and the status says checking or something similar, it takes maybe 4-5 seconds.

I don't seed 24/7, I shut down the PC most of the time, and I don't have all the HDDs on auto mount, I have remember to mount them before starting qbittorrent or it wont find half of the files.

Thank you for this clarification, I will try to exit qbit and launch it again when HDD is accessible. Maybe it will reset those error statuses. I think it didn't work some years ago (error status remained, had to start verification).

Seems reasonable, I didn't thought about port conflict. But in this scenario not running both clients at the same time also is an acceptable solution.

Now I'm having doubts about it. I know for sure that with Transmission it worked that way, on second start all the torrents with missing files were paused. With qpittorrent, one hour ago, I was pretty sure I didn't need to unpause the torrents but now I'm affraid of missremembering something. As soon as I get home in a couple hours I'll test it to make sure.

Edit: confirmed, all torrents resume correctly without having to verify them.

This is what I do as well. My destination drive is luks encrypted and I often forget to unlock it first. All torrents red? Oops. Close qbt, unlock and reopen.

Confirmed as well. Also, stopping them before unmounting drive doesn't prevent missing files error.

I have no experience with this, at all, but could creating symlinks from your internal SSD to your external HDD perhaps solve this issue?

I suspect there were no issue in the first place. A lot of time ago, if torrent client encountered files are missing, you had to run long process of verification for them to become available for seeding.

Now, if torrents switched to "files are missing" you can restart torrent client and seed like if nothing happened. No need for categories even. Also, function "Set location" can be used to move torrent to external storage.