VM had dasd read/only for volser (vol1 record) to identify each mounted disk. VM r/w activity was limited to vm page formated disks.
CMS running in virtual machine had support for cms filesystems and some primitive support for real formated OS & DOS disks. regarding incorrently rewriting vtoc ... there is some possibility it might have happened if somebody had attached/linked the real disks to cms in a virtual machine (in r/w mode). In the mid-70s, one of the people in the vm370/cms development group significantly rewrote and developed full function OS r/w filesystem (real os vtoc, pds directory, etc.) function in CMS (joke that the <100k bytes was more efficient os/360 similiation than the 8+mbytes that had been done in MVS for os/360 simulation). however this was approx. the period when FS effort was imploding and there was mad rush to get products back into the 370 pipelines (during FS effort, 370 activity was being suspended and/or killed off). misc. past posts mentioning Future System effort (that was going to completely replace 360/370) http://www.garlic.com/~lynn/submain.html#futuresys As part of reconsituting 370, (303x was kicked off in parallel with 370/xa) and the head of POK managed to convince corporate to kill off vm370 product, shutdown the development group and move all the people to POK ... or otherwise they wouldn't be able to meet the mvs/xa ship schedule. somehow the vm370 development group was warned ahead of time and some of the people managed to escape being moved to POK (there was joke about head of POK was major contributor to DEC vax/vms). in the killing off of the vm370 product and shutdown of the group ... before the full function OS filesystem support shipped ... and it all just disappeared. Eventually, Endicott managed to save the vm370 product mission, but they had to reconstitute a development group from scratch. -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
