You might want to explore IBM's 'SafeGuarded Copy' to see whether it meets your needs.
A Red Paper called 'IBM DS8000 Safeguarded Copy (Updated for DS8000 Release 9.1)' was published in March of this year (REDP-5506-01) -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Charles Mills Sent: Tuesday, July 13, 2021 5:07 PM To: [email protected] Subject: Re: Can I define a disk as read only to z/OS? CAUTION: This email originated from outside of the Texas Comptroller's email system. DO NOT click links or open attachments unless you expect them from the sender and know the content is safe. The IBM Dallas development system has VM volumes mounted read-only to the z/OS client machines. I know zero details of the CP side but I see it from the z/OS side. IBM has shared SYSRES-type volumes for multiple clients. Yes, z/OS reports I/O errors if it tries to write to them, but it all works, and obviously IBM knows what they are doing. The point is Yes, a z/OS read-only disk is possible. I don't think z/OS "knows" it is read-only, so it tries to write and reports errors, but it survives just fine. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of John McKown Sent: Tuesday, July 13, 2021 1:31 PM To: [email protected] Subject: Re: Can I define a disk as read only to z/OS? z/OS does not have the concept of a readonly disk. The z/OS mount command will allow the USE=PRIVATE option. But that is not readonly. In the past, under z/VM, I would use a full pack minidisk with I defined in the directory as readonly. This worked, but did cause I/O errors to be reported on z/ OS when it tried to update the date stamp in the VTOC entry for DSNs when they were OPENed. On Linux, there is a readonly option on the mount command for a filesystem. On Tue, Jul 13, 2021, 13:40 Colin Paice <[email protected]> wrote: > I am migrating to the latest levels of ADCD ( C4* instead of A4*). > During the migration I would like to be able to mount the A4* volumes > on the C4 system, but mount them read only. > I can change the Linux disk to be access mode 444, but if I want to > IPL from A4* I need to change it back again. > The z/OS documentation mentions usingn read-only disks, but I can't > see how to do it. I dont think I can do it from the HCD > OA50068: NEW FUNCTION - PROVIDE READ-ONLY ACCESS FOR SYNCHRONOUS PPRC > SECONDARY DEVICES > <https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ibm.com%2Fsupport%2Fpages%2Fapar%2FOA50068&data=04%7C01%7Cmichael.watkins%40CPA.TEXAS.GOV%7Ceeb868f143104b9a795908d9464a9be8%7C2055feba299d4d0daa5a73b8b42fef08%7C0%7C0%7C637618109601947015%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=GqALszAgG1nknvsc2gkIuM5wDMGSLraVw%2FVVl%2BTgz%2FA%3D&reserved=0> > Looks like it is only for PPRC. > Do I just have to live with changing the access mods to/from 444. > Colin > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
