[regression] qBT does a lot of unnecessary writes to its files

[zetok]

qBittorrent: v3.3.4
Qt: 5.5.1
libtorrent: 1.0.7.0
boost: 1.56.0
OS version: Gentoo Linux amd64

Regression happened most likely between 3.3.3 → 3.3.4. For sure there was no such problem on 3.1.12.

on 3.3.4 qBittorrent does a lot of unnecessary writes to its .fastresume files, which causes HDD trashing.

Steps to reproduce:

1. Have downloaded torrents
2. Wait for qBT to do unnecessary removes & additions of files (happens every few minutes)

↓ done by qBT, written per second.

[DrKittens]

Can replicate "unneccessary writes" under debian 8, windows 7 and windows 10.
Allowing qbittorent to connect to DHT then disabling the internet connection causes it to continue performing these writes so its NOT related to seeding/downloading behaviour as far as i can tell.

Why is it touching .fastresume files while under operation..?

[Misiek304]

Why is it touching .fastresume files while under operation..?

Maybe to prevent data loss and corruption upon crash or sudden power outage?

[zetok]

Maybe to prevent data loss and corruption upon crash or sudden power outage?

Seemed to work just fine without constant deletes & writes before.

[thalieht]

You wouldn't be talking about "Save resume data interval" in advanced settings?

In win 7 with the official 3.3.4 i don't have that problem, or at least i don't think i have it? In file explorer .fastresume files seem to get overwritten on that interval, nothing strange, and resource monitor shows 0B/s writes.

qBittorrent: v3.3.4
Qt: 5.6.0
libtorrent: 1.0.8.0
boost: 1.60.0

[zetok]

You wouldn't be talking about "Save resume data interval" in advanced settings?

Oh, looks like it was added recently? I didn't notice it. Well, setting it to reasonable period like 600 min should do as a workaround.

With that being said, files still shouldn't be overwritten if there is no reason to.

[thalieht]

That's...reasonable only if you're seeding and don't care about stats or don't care about rechecking torrents in case of crash or power surge or some other calamity.
While we're on the subject, as suggested elsewhere, there should be an option to disable saving fastresume data for torrents in X state such as seeding, completed and definitely paused and only save metadata for these torrents when exiting qBt (and when entering that state in cases of completed and paused).

[ngosang]

We are closing all issues related to old qBittorrent versions (qBittorrent < 4.1.0).
Please, update to last release and, if the bug/error/crash is still present, open another issue.
Thank you.

[thalieht]

This should be fixed anyway. Now we write to .fastresumes on change events instead of relying on the interval. The default interval has also been increased to 60 min.

[ngosang]

@thalieht please help me!!!
`

[thalieht]

😄 I'll go to sleep soon, tomorrow.