disable_os_cache has no effect #16819

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opened 2026-02-22 03:26:44 -05:00 by deekerman · 3 comments

deekerman commented

2026-02-22 03:26:44 -05:00

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Originally created by @axet on GitHub (Apr 29, 2025).

qBittorrent & operating system versions

qBittorrent v5.0.4 (64-bit)
debian trieixe

What is the problem?

I'm using qbittorrent 5.0.4 with 'Disk IO read mode' set to 'Disable OS cache' which corresponds to 'disk_io_read_mode=disable_os_cache' libtorrent option. It seems option has no effect on actual file caching.

Steps to reproduce

ran dropcaches
ran 'vmtouch -v /torrent_path' == shows 0GB cached
ran torrent on /torrent_path folder for 5 mins
ran 'vmtouch -v /torrent_path' again and it showing 7GB cached

Additional context

I expect vmtouch will show 0GB after torrenting, but it seems files still get into system cache I guess O_DIRECT not working?

Log(s) & preferences file(s)

qBittorrent.conf.gz

Originally created by @axet on GitHub (Apr 29, 2025). ### qBittorrent & operating system versions qBittorrent v5.0.4 (64-bit) debian trieixe ### What is the problem? I'm using qbittorrent 5.0.4 with 'Disk IO read mode' set to 'Disable OS cache' which corresponds to 'disk_io_read_mode=disable_os_cache' libtorrent option. It seems option has no effect on actual file caching. ### Steps to reproduce 1) ran dropcaches 2) ran 'vmtouch -v /torrent_path' == shows 0GB cached 3) ran torrent on /torrent_path folder for 5 mins 4) ran 'vmtouch -v /torrent_path' again and it showing 7GB cached ### Additional context I expect vmtouch will show 0GB after torrenting, but it seems files still get into system cache I guess O_DIRECT not working? ### Log(s) & preferences file(s) [qBittorrent.conf.gz](https://github.com/user-attachments/files/19954405/qBittorrent.conf.gz)

deekerman added the

Libtorrent

label

2026-02-22 03:26:44 -05:00

deekerman commented

2026-02-22 03:26:49 -05:00

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@xavier2k6 commented on GitHub (Apr 29, 2025):

xref: https://github.com/arvidn/libtorrent/issues/7936

@xavier2k6 commented on GitHub (Apr 29, 2025): xref: https://github.com/arvidn/libtorrent/issues/7936

deekerman commented

2026-02-22 03:26:49 -05:00

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@axet commented on GitHub (May 19, 2025):

I tried to run qbittorrent with pread+pwrite and 'nocache 1.2-0.1' cache still generated by reading torrents. I guess qbittorrent can handle O_DIRECT without libtorrent support.

@axet commented on GitHub (May 19, 2025): I tried to run qbittorrent with pread+pwrite and 'nocache 1.2-0.1' cache still generated by reading torrents. I guess qbittorrent can handle O_DIRECT without libtorrent support.

deekerman commented

2026-02-22 03:26:49 -05:00

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@HanabishiRecca commented on GitHub (May 19, 2025):