We had these conversations here, but there are pitfalls. If you format the first couple of cylinders, it would probably fool the kernel, but then the disk only APPEARS to be properly formatted to z/Linux. If the owner of the z/Linux guest does not remember to reformat it after it is given to the guest, they could easily forget that most if it is still unformatted. They might even get far enough to pvcreate it, and add it to a VG, only to find out when they run mkfs that it is mostly bad.
At BEST, because the labels and fake VTOC only show a disk of a few cylinders, the remaining space might be ignored. At worst, you'd get the error messages again. We know dasdfmt issues some kind of call to return device geometry through the kernel, but whether that's used only for formatting, or by the kernel itself, is not clear. If you CMS format the disk, it is good enough for the kernel not to issue the error messages, but still reports bad whenever you run a z/Linux utility against it. Our z/Linux guru had a look at the dasdfmt utility source code. It doesn't really DO anything itself, it uses an "ioctl" call to the kernel driver to perform the actual formatting. The channel programs that do that are all in the kernel. -----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Alan Altmark Sent: Friday, November 30, 2007 11:07 AM To: [email protected] Subject: Re: Formatter forz/Linux Minidisk from CMS On Friday, 11/30/2007 at 09:58 EST, "Stracka, James (GTI)" <[EMAIL PROTECTED]> wrote: > Kludge yes, one pack; no. Because of striping we would need at least > thirteen differently sized template minidisks. Unless we could format just > one very large minidisk and image copy as little as needed. I > believe CMS > gets just a little bent out of shape if one did this. Would not z/Linux > too? Formatting just one cylinder on the pack should be sufficient since that will write the volume label and let Linux recognize it. Alan Altmark z/VM Development IBM Endicott -------------------------------------------------------- This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/. By messaging with Merrill Lynch you consent to the foregoing. --------------------------------------------------------
