> -----Original Message----- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On > Behalf Of Coffin Michael C > Sent: Thursday, May 26, 2005 2:34 PM > To: [email protected] > Subject: Re: Change Linux DASD Label > <snip> > > PS: Anyone have any idea why z/OS is even mentioned in this > message? Is > this yet another use of "z/OS" where "z/Series" should be? > There is more > than one z/Series OS out there ...... :) > > Michael Coffin, VM Systems Programmer > Internal Revenue Service - Room 6527 > 1111 Constitution Avenue, N.W. > Washington, D.C. 20224
Originally, Linux used what is called LDL - Linux Disk Label. This "label" was not in a z/OS standard format (the same disk label is used by z/OS, z/VM and z/VSE, all the way back to DOS/360 - DOS/360 was the "first" S/360 OS generally available, I think). Anyway, this meant that when z/OS was IPL'ed it would "whine" to the operator (something like "UNLABELED DASD ON XXXX PUT OFFLINE", IIRC). So, when IBM learned that the z/OS storage admins were fixing to kill the Linux people, they (or somebody) came up with CDL (Compatable Disk Label?) format. In this format, there is a compatable VOL1 record and pointer to a valid OS VTOC (Volume Table Of Contents). The VTOC in this case acts like the "partition table" on an PC's hard disk. This also allows IBM's DFDSS (and Innovation's FDR) product to backup the Linux volumes (with the usual caveat that they not be mounted R/W to some Linux image) the same way that z/VM and z/VSE volumes could be backed up. HTH -- John McKown Senior Systems Programmer UICI Insurance Center Information Technology This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its' content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited. ---------------------------------------------------------------------- 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
