Ok to set RESTIC_CACHE_DIR to external drive?

Getting Help
1

Is it a bad idea to put the huge RESTIC_CACHE_DIR on an external SSD?
I’m wondering if there are performance implications and/or robustness implications (I sometimes accidentally unplug the drive without properly stopping restic and ejecting the disk)

restic 0.18.0 compiled with go1.24.2 on darwin/arm64

2

It’s fine to do that. You will be bound by the performance of accessing that disk instead of accessing whatever else you’d put the cache dir on otherwise.

2 Likes
3

It is even recommended to put it on ram-disk. Restic will initialize it every time it got lost after a reboot.
export RESTIC_CACHE_DIR=/dev/shm/restic-cache

1 Like
4

Really? That seems strange to me. I don’t know the technical details but I would have guessed that’s equivalent to running with --no-cache

5

Clearly --no-cache and cache somewhere (RAM, internal disk, external disk) is not the same:)

As long as your cache location is faster than your remote access you will see its benefits.

IMO using RAM for restic cache is wasteful but of course possible.

6

oh yeah makes sense. brain fart

7

Using RAM makes sense if you make several backups/query in succession before the ramdisk is deleted. If you only access the Repository once, then of course it is unnecessary.