On Tuesday, 06/10/2008 at 05:15 EDT, Mark Post <[EMAIL PROTECTED]> wrote: > The uid comes from the storage device itself. From one of my z/VM guests: > # cat /sys/bus/ccw/devices/0.0.0150/uid > IBM.75000000026069.1014.16 > > It is supposed to be unique to the hardware device itself, based on serial > number, or some such thing. If the actual hardware changes, so does that > value. The "by-name" value gets generated by the Linux kernel, based on the > order of the device numbers that get passed to it. That's why the names are > not persistent, and can change if the kernel parameters are changed without > preserving the original order.
The UID is indeed unique to the device. It consists of manufacturer's name, plant of manufacture, and a serial number. That allows you to identify a volume, independent of how you access it (UAs, device numbers, chpids, etc.). Alan Altmark z/VM Development IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
