Gfilui

I'm running Ubuntu 15.10, 17,04 and 17.10. I've a USB 3.0 Sandisk Extreme flash drive and a motherboard with USB 2.0 and USB 3.0 ports.

The flash drive has two partitions:
1 A Fat32 MULTISYSTEM UEFI boot, esp partition
2 An ext4 data partition

I can boot from the flash drive but when I insert the flash drive in a running system, the UEFI boot partition has to be manually mounted. The ext4 data partition automounts and is visible in Nautilus as expected.

Testing on 15.04, both USB 2.0 and USB 3.0 ports work the same.

I've set dconf-editor (org.gnome.desktop.media-handling) automount=TRUE

journalctl shows that the USB device is recognised and udisks mounts the data partition at sdb2

Feb 07 11:14:08 John01 kernel: usb 1-8: new high-speed USB device number 13 using xhci_hcd
Feb 07 11:14:08 John01 kernel: usb 1-8: New USB device found, idVendor=0781, idProduct=5580
Feb 07 11:14:08 John01 kernel: usb 1-8: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Feb 07 11:14:08 John01 kernel: usb 1-8: Product: Extreme
Feb 07 11:14:08 John01 kernel: usb 1-8: Manufacturer: SanDisk
Feb 07 11:14:08 John01 kernel: usb 1-8: SerialNumber: AA010107141849202082
Feb 07 11:14:08 John01 kernel: usb 1-8: ep 0x81 - rounding interval to 16 microframes, ep desc says 20 microframes
Feb 07 11:14:08 John01 kernel: usb 1-8: ep 0x2 - rounding interval to 16 microframes, ep desc says 20 microframes
Feb 07 11:14:08 John01 kernel: usb-storage 1-8:1.0: USB Mass Storage device detected
Feb 07 11:14:08 John01 kernel: scsi host9: usb-storage 1-8:1.0
Feb 07 11:14:08 John01 mtp-probe[3593]: checking bus 1, device 13: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-8"
Feb 07 11:14:08 John01 mtp-probe[3593]: bus: 1, device: 13 was not an MTP device
Feb 07 11:14:09 John01 kernel: scsi 9:0:0:0: Direct-Access SanDisk Extreme 0001 PQ: 0 ANSI: 6
Feb 07 11:14:09 John01 kernel: sd 9:0:0:0: Attached scsi generic sg2 type 0
Feb 07 11:14:09 John01 kernel: sd 9:0:0:0: [sdb] 122544516 512-byte logical blocks: (62.7 GB/58.4 GiB)
Feb 07 11:14:09 John01 kernel: sd 9:0:0:0: [sdb] Write Protect is off
Feb 07 11:14:09 John01 kernel: sd 9:0:0:0: [sdb] Mode Sense: 33 00 00 08
Feb 07 11:14:09 John01 kernel: sd 9:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Feb 07 11:14:09 John01 kernel: sdb: sdb1 sdb2
Feb 07 11:14:09 John01 kernel: sd 9:0:0:0: [sdb] Attached SCSI disk
Feb 07 11:14:09 John01 kernel: EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null)
Feb 07 11:14:09 John01 udisksd[1842]: Mounted /dev/sdb2 at /media/john/Data on behalf of uid 1001

I can manually mount /dev/sdb2.

A second flash drive with a single UEFI boot partition is also recognised by the kernel, but isn't mounted and I am unable to mount it manually.

Is the failure to automount connected to the UEFI boot status of the partition? Can you suggest how to get it working?