I am issuing DIAGNOSE 8 on my z/os image under VM (z/vm) to do a QUERY VIRTUAL DASD. It works—up to a certain point:
The QUERY VIRTUAL DASD command returns (for me) 38617 (decimal) bytes, according to the CC=0 after the DIAGNOSE 8 command. My buffer is large enough to accommodate this. I have tried several different sub-pools of storage. I PGSER FIX the buffer pages. I do a SYSEVENT DONTSWAP. I do a LRA of the virtual address of the start of the buffer. The DIAGNOSE completes CC=0. But, in my buffer, I am only seeing the first page (4095) bytes of the output. My question: I don’t see any documented restriction in the VM manuals that limits the DIAGNOSE 8 output buffer to 4K (rather the limitation is the architecture limit depending on your amode.) The z/vm manuals say the buffer can cross page boundaries. So is there a way to force the real storage addresses of the page-fixed pages to be consecutive? According to the diagnose 8 doc., the buffer needs to be in guest-real storage, hence the LRA. And it is working for the first 4k page. Thank you for any insight you can provide. Paul ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
