At 17:21 27-08-02, Gary A. Ernst wrote: >I Have installed kernel 2.4.17 and IBM patches as well as the s390-tools. Run >zipl and rebooted When I run zipl again I get IPL form CMS reserved minidisks >not supported cannot continue. Am I missing something or has this support >actually been dropped ?
While this is not really an answer, I believe it never worked or has been broken very long time ago. ;-) My apologies for the long explanation, but maybe this explains both things you see. The way Linux deals with writing the IPL records is by insisting that the architectured IPL records R1 & R2 are part of the payload of the disk (and skip the first tracks when data is written to disk). With the CMS Reserved mini disk the payload portion does not include the first few blocks, but only the blocks within that single file. Thus Linux cannot reach the IPL record through that mechanism. Unfortunately the zipl code was such that it got confused by a CMS reserved mini disk such that it corrupted the data on the disk instead. Otherwise it would be trivial to make a CMS program that puts an IPL record on disk that will pick up the IPL record that Linux puts in the payload portion of the disk. The PFAULT support then broken the external interrupt handler such that a Linux kernel hangs when trying to initialize a CMS reserved mini disk. From what I have seen SuSE have configured their kernel not to include the diagnose driver (only as a module so you can hang yourself on demand). A patch for this problem was published but I was unable to put it on yet since it bites the demand timer code. The net result is that currently the non-CDL discipline of the Linux dasd driver picks up the CMS reserved disk as plain CMS formatted, and will write data blocks from R4 or R5. In some cases this corrupts what's left of CMS FST's so that ACCESS of the disk will hang your backup programs or scanning software. The moral of this is probably right now to use CDL format until we sorted out all issues with the diagnose driver and then see whether we need to convert. Rob
