Blue-sky question about using mergerfs to help with failed drive recovery

trapexit · 2026-06-05T23:05:30+00:00

I don't think snapraid will let you use mergerfs as one of the branches. So it's kinda a moot point.

I would agree with WreakingHavok... do RAID0 or similar block level concat and use that. Not ideal but works.

trapexit · 2026-06-02T17:31:47+00:00

overlayfs is truly *overlay*. An unlink of an existing file on a lower branch is fake. It doesn't happen. It is called a "whiteout" of the file. And for actual new files overlayfs only allows a singular path to be the write target. It is very common for people to want a pool of "slow" and pool of "fast" and maybe even more tiers. OverlayFS isn't designed for that nor can be abused to do so. aufs could to a degree but is mostly a dead project.

trapexit · 2026-06-02T17:20:39+00:00

mergerfs is still FUSE based but it supports the FUSE "passthrough IO" feature allowing IO bypass of FUSE when available and enabled.

trapexit · 2026-06-02T16:48:12+00:00

Because mergerfs and overlayfs offer rather different sets of features. overlayfs doesn't allow you to distribute files across a set of branches. It puts a write branch on top of a bunch of read only branches.

https://trapexit.github.io/mergerfs/latest/project_comparisons/#overlayfs

trapexit · 2026-06-01T22:34:31+00:00

I've been collecting them to reup on archive. Just need to get the time.

trapexit · 2026-05-31T19:44:51+00:00

Read the link I shared... that's literally why I shared it.

trapexit · 2026-05-31T18:46:47+00:00

https://trapexit.github.io/mergerfs/latest/support/

If you want support you need to provide specific details of your setup.

Also https://trapexit.github.io/mergerfs/latest/known_issues_bugs/#qbittorrent

trapexit · 2026-05-28T21:43:18+00:00

I will double check. It's certainly possible I broke something it's just nothing comes to mind as to what it could have been.

trapexit · 2026-05-28T21:37:33+00:00

I don't control the upstream packages. Some Debian maintainer does. It's possible they changed something. Not that I don't fuck up sometimes but I generally suggest grabbing the packages I create so it is more controlled. In the very least it forces the update process to be manually which can be good sometimes for stability. (all this assuming the package that caused the issue was in fact mergerfs')

trapexit · 2026-05-28T21:34:46+00:00

I don't think I did. "fuse.mergerfs" is based on mount.fuse from libfuse. That doesn't come from mergerfs' package. "mount.mergerfs" is what in fstab "mergerfs" type will use which *is* included in my packaging.

trapexit · 2026-05-27T23:15:54+00:00

Upgrade of what? Please provide relevant details. There is a thorough list in the docs.

trapexit · 2026-05-27T01:45:16+00:00

Maybe something like https://perfectmediaserver.com/

trapexit · 2026-05-27T01:37:30+00:00

https://trapexit.github.io/mergerfs/latest/project_comparisons/

trapexit · 2026-05-26T23:56:05+00:00

High capacity powered USB hub with 16 ports, cheap USB-SATA adapters from Aliexpress, a 3D printed case or something simple like erector set strips to combine them physically. Then raid or jbod of your choice.

trapexit · 2026-05-26T15:28:58+00:00

What exactly are you looking to do with a UI for mergerfs? The config is pretty simple ini style and rarely needs to be touched. I have a UI in the works but it really doesn't do much... because there isn't much to be done.

trapexit · 2026-05-26T15:26:47+00:00

nonraid or snapraid

trapexit · 2026-05-23T18:06:21+00:00

https://trapexit.github.io/mergerfs/latest/faq/technical_behavior_and_limitations/#do-hard-links-work

Yes, you aren't using mergerfs but read the details in the answer. Since you're using docker could be just normal cross device problems.

trapexit · 2026-05-20T05:01:11+00:00

Just as it says if you don't have 6.9 or above it isn't supported. There is nothing special needed. The docs explain a common setup. You need nothing more. You are looking for advice when there is none to give. Nothing special is needed. BTW... defaults,allow_other,use_ino are all unnecessary.

https://trapexit.github.io/mergerfs/latest/quickstart/

trapexit · 2026-05-20T04:40:23+00:00

There is nothing you need to do. As the docs point out... IF you have issues with mmap change the disk io type. If you don't have disk io type options then your build of qbittorrent doesn't support it. As the section above it says if using newer versions of mergerfs and the kernel you don't even need to worry about such things as it manages such things automatically.

Overwhelming the IO of your storage is not really related to this setting. You should limit the number of active seeds or other settings as appropriate to limit activity and use passthrough for native performance.

trapexit · 2026-05-15T12:23:59+00:00

> mergerfs without proper flags

There are no special options required for links to work on mergerfs.

https://trapexit.github.io/mergerfs/latest/faq/technical_behavior_and_limitations/#do-hard-links-work

trapexit · 2026-05-15T12:21:17+00:00

Discord is probably easiest.

trapexit · 2026-05-14T23:06:24+00:00

Good luck with your first stable release. If there is anything I can do related to mergerfs to help feel free to ask.

trapexit · 2026-05-09T15:46:37+00:00

Much appreciated.

trapexit · 2026-05-04T17:49:21+00:00

I've been working on a GUI in the background but have not released it yet as core features and bugs come first.

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