Hi fellow listers, We are intending to convert our non-root z/Linux filesystems to live on SCSI disk. I've read all the doco I could find and trawled the VM and Linux-390 Listservers, but found very little that tells me what I need to specify in SYSTEM CONFIG and USER DIRECT for SCSI. I would greatly appreciate if somebody experienced with SCSI disk would verify if I have the following correct. And if not, what I need to specify instead.
I am unsure whether we will use SCSI direct or as emulated 9336-20's for z/Linux. Are there recommendations here? I would expect direct would have better performance. Emulated 9336-20's: We manage our I/O configuration using HCD under z/OS in another LPAR. This is where we would define the SCSI disk. Therefore, from what I have read: - I do not need (and am not allowed) to specify EDEVICE statements in SYSTEM CONFIG. - Since the SCSI disk could never be online to MVS, I do not need a dummy VTOC on "cylinder" 0 and therefore can define a full-pack minidisk on each SCSI disk. Therefore, there is no VOLSER from z/VM's perspective. So I can't specify the SCSI disk in the User_Volume_Include list in SYSTEM CONFIG. - I should specify the rdev=edev device address in the Devices Accepted and Devices Online_At_IPL lists. - In USER DIRECT, I specify MDISK vdev 9336 DEVNO rdev MR R W M Real SCSI: - In SYSTEM CONFIG, there is no VOLSER from z/VM's perspective and so I can't specify the SCSI disk in the User_Volume_Include list. - I should specify the rdev device address in the Devices Accepted and Devices Online_At_IPL lists. - In USER DIRECT, I specify DEDICATE vdev rdev and no MDISK statement. Many thanks in advance. Regards, Fred Schmidt DCS DBE, NT Government, Australia
