Add LVM SSD Cache to existing VG/LV

Help
1

Hey there,

I have a running nixOS system and I would like to extend it by altering the volume group of the root FS, add another logical volume and have it assigned to another pre-existing logical volume as writeback cache.

Can I simply alter the volumes manually using the vg*/lv* commands or would I need to configure this change in nixOS’ configuration? Does the config support LVM caches?

Thanks & regards,
Marius

2

I’m just guessing here, but I’m pretty sure, you’re fine just doing it manually.
Just like formatting, LVM configuration is not done by NixOS, but by the user at install time.
The partitions are only reflected in the NixOS configuration so that they can be automatically mounted.

3

Thank you Mr. Zoidberg, you were right, nixOS doesn’t seem to care about the LVM configuration and will leave it alone. Performed all the necessary steps manually and it’s working now.

Problem solved.