Udevadm

udev management tool http://man7.org/linux/man-pages/man8/udevadm.8.html

udevadm --debug settle
udevadm --debug settle -E /dev/sdz44
-E Stop waiting if file exists.

See also

• udev, /dev/, udevadm, udevadm info
• Block devices: blkid (UUID), lshw -class disk, hwinfo --disk, udevadm, rescan-scsi-bus.sh, LUN, hdparm, findfs, Add a new disk
• lsblk, pvscan lspci, lsscsi, smartctl, fdisk, parted, Kpartx, pvdiplay, pvs, udisksctl, /dev/sd, nvme list
• Systemd: systemctl, systemd-journald, journalctl systemd-cat, systemd-logind, systemd-networkd:networkctl, systemd-timesyncd, systemd-resolved, systemd-udevd , Systemd-logind: loginctl, hostnamectl, udevadm, systemd-run, portablectl, systemd-nspawn, systemd resource management, Timer (systemd), systemd logs, /etc/systemd/, systemd services, systemd-mount, /run/systemd/, .service, /usr/lib/systemd/, /usr/lib/systemd/system/, /usr/lib/systemd/system/systemd-resolved.service, /lib/systemd/, machinectl, systemd-oomd, systemd-analyze

https://wiki.ubuntu.com/DebuggingSystemd