Need some help with a disk replacement (cache)

[p-user]

I have a USB drive as cache for the S3 datastore, mounted under /mnt/datastore/cache.
Now I want to replace this USB drive with another one, but get stuck how to do this.
I copied the data from the existing disk to the new one. But how do I get the system to use this new disk, mounted under /mnt/datastore/cache.
I can see that the disk is mounted using the disk ID, but cannot find any file that contains this value (and I could replace the disk ID of the old disk with the ID of the new one).

Any help appreciated.

Albert

 

[Chris]

I have a USB drive as cache for the S3 datastore, mounted under /mnt/datastore/cache.
Now I want to replace this USB drive with another one, but get stuck how to do this.

I would recommend a fast local NVME disk as cache device, usb attached disks are not ideal for this.

Now I want to replace this USB drive with another one, but get stuck how to do this.

For reference, see https://forum.proxmox.com/threads/s3-backup-status.170659/post-800928

 

[p-user]

Thanks Chris,
again, many thanks.

Albert
P.S. Unfortunately, there is no room in my mini PC for an extra nvme drive, so the nvme drive is in a USB enclosure, not ideal, but it'll have to do.

 

[UdoB]

Unfortunately, there is no room in my mini PC for an extra nvme drive, so the nvme drive is in a USB enclosure, not ideal, but it'll have to do.

That's the curse of such physically small devices. Keep in mind that "not ideal" may mean different things; one not obvious aspect in one of my systems is this:

        rpool                                                ONLINE       0     0     0
          mirror-1                                           ONLINE       0     0     0
            nvme-eui.0000000001000000e4d25c47df365401-part3  ONLINE       0     0     0  (100% trimmed, completed at Mon Sep 15 00:57:08 2025)
            usb-KIOXIA_EXCERIA_PLUS_23HFB13SFPH4-0:0-part4   ONLINE       0     0     0  (trim unsupported)

This specific pool is massively oversized, so I tolerate the loss of trimming capabilities...

Anecdotical: I had added that USB device after the NVMe got me into trouble, two years ago. After adding this one (and after some months of usage) I've had two failures of the USB enclosure ("device not available") and zero problems with the internal one.

In my (small) universe USB is not reliable on the long run - and I will not recommend to use it.