On Monday, 08/17/2015 at 12:44 EDT, Mark Post <[email protected]> wrote:
> Part of the problem (for me at least) is that you're using the word > "attach(ed)" which in the z/VM context has a specific meaning. What you're > doing is not ATTACHing a DASD volume to a guest, you're giving it one or more > minidisks out of a pool of DASD ATTACHed to SYSTEM. When I teach VM, the first thing I do is insist on use of correct terminology. Failure to abide simply results in confusion later on down the line. To help, just keep seven simple rules in mind: 1. A virtual machine may not directly use real devices; it may use only virtual devices. 2. Virtual devices can be simulated, emulated, or dedicated. 3. Virtual devices are generally created by the CP DEFINE (simulated, emulated), LINK (emulated), and ATTACH (dedicated) commands. 4. The directory has statements that do the same things as DEFINE, LINK, and ATTACH. 5. Class B users MUST use QUERY VIRTUAL <device> when they want to know about virtual devices. 6. Class B users MUST use QUERY <device> when they want to know about real devices. 7. CP can't read your mind. Glossary o A simulated device exists only within CP. Ex: PRT, PUN, RDR, NIC, VDISK. o An emulated device converts the semantics of virtual device A to those of real device B. Device B is instantiated outside of CP. Ex: EDEVICE, minidisk, crypto, guest console. o A dedicated device exists only outside of CP. With few exceptions, the virtual machine has access to all of the native capabilities of the device. Alan Altmark Senior Managing z/VM and Linux Consultant Lab Services System z Delivery Practice IBM Systems & Technology Group ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 [email protected] 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 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
