[Question] ttys0 since OP 1.6.0

I have ttys0 beside Auto and ttyUSB0 in OP since update to 1.6.0. What is this for?
I connect through ttyUSB0. Can i disable ttys0 ?

It's a built-in serial port. No option to disable but shouldn't matter if you select the appropriate port.

I was just wondering why it appeared after update to 1.6.0 and not with 1.5.3.

If you want to keep OctoPrint from trying to use that for connecting, add it to the 'Blacklisted serial ports' option in Settings->Serial Connection.

Or add the wild card in the note for that setting: /dev/ttyS*

If you tell us from which version you came I might also be able to solve the mystery why this suddenly popped up after update. With OctoPrint 1.4.0 ttyS* was added to the default pattern of recognized serial ports. If you haven't updated in over a year, that would explain it. That it shows up could be due to a touchscreen or a camera - it shouldn't be there by default, but additional hardware can explain its presence. See also:

As mentioned, you can just blacklist it (the plugin was only needed for OctoPrint 1.4.0, 1.4.1 introduced the port blacklist)

Ya know. I thought that existed but must have looked right by it when checking.

Updated from 1.5.3. ttys0 was not present with 1.5.3. I have a touchscreen with octodash and a USB Webcam connected, but these was connected with 1.5.3 too. Will try blacklist

There was no change in the detected port patterns, so either some blacklist entry you already had got wiped out somehow (not aware of any update related hiccups that could cause that) or some other change on the system unrelated to the OctoPrint update made the port pop up. OctoPrint doesn't make serial ports appear on your system, either they are there or they aren't, the only way something can suddenly show up is by either physically appearing anew or by a change in the default port patterns or blacklist.