failed to start jack when different user login in Manjaro KDE 21.1.2

[rafidalhaque]

When I login with a different user credential, and going to start jack with cadence. It shows me a error message that,

failed to start jack, please check the logs for more information.

and the log is here:

Sun Sep  5 13:43:45 2021: Starting jack server...
Sun Sep  5 13:43:45 2021: JACK server starting in realtime mode with priority 10
Sun Sep  5 13:43:45 2021: self-connect-mode is "Don't restrict self connect requests"
Sun Sep  5 13:43:45 2021: ERROR: Cannot lock down 107341340 byte memory area (Cannot allocate memory)
Sun Sep  5 13:43:45 2021: ERROR: Cannot open DB environment: Permission denied
Sun Sep  5 13:43:45 2021: Acquired audio card Audio0
Sun Sep  5 13:43:45 2021: creating alsa driver ... hw:PCH,0|hw:PCH,0|1024|2|48000|0|0|nomon|swmeter|-|32bit
Sun Sep  5 13:43:45 2021: ERROR: 

ATTENTION: The playback device "hw:PCH,0" is already in use. Please stop the application using it and run JACK again
Sun Sep  5 13:43:45 2021: ERROR: Cannot open DB environment: Permission denied
Sun Sep  5 13:43:45 2021: Released audio card Audio0
Sun Sep  5 13:43:45 2021: ERROR: Cannot initialize driver
Sun Sep  5 13:43:45 2021: ERROR: JackServer::Open failed with -1
Sun Sep  5 13:43:45 2021: ERROR: Failed to open server

System information:

OS: Manjaro Linux x86_64 Host: H310M S2H 2.0 Kernel: 5.13.13-1-MANJARO CPU: Intel i3-8100 (4) @ 3.600GHz GPU: Intel CoffeeLake-S GT2 [UHD Graphics 630]

How can i solve this problem, please?

[falkTX]

This is not supported in Cadence, using jack with the same audio card for multiple users. There is a special way to allow jack to work on such setups, but I never tried it myself and do not even know if it still works. If you need something to keep researching, this is called "promiscuous mode". Still unsupported in Cadence though.