Cache creation failed: get_device for source device failed.

[sinashan]

Hey guys,
I was trying to create a cache using this command:

sudo eio_cli create -d /dev/sdc1 -s /dev/sdb5 -p lru -m wb -c new_cache

But I'm getting the error in the title. Both directories seem to be valid and I'm not sure where the error could rise from. I'd appreciate your help.

Thanks

P.S: I'm using centos 7 if that helps.

[sinashan]

found the answer (it was just a beginner mistake I'd made.)

For future novice users: You should format your partitions (if they are external like USB devices) as Ext4. At least that was what solved my problem.