SCSI dump is a stand-alone dump to a SCSI disk. It is the IPL of an operating system-dependent dump program.
An initiated SCSI dump always performs a store status automatically. A reset normal instead of reset clear will be performed, which does not clear the memory.
Machine loader and system dump program run in the same LPAR memory that must be dumped. For this reason the lower-address area of the LPAR memory are copied into a reserved area (HSA) of the machine. The system dump program then reads the first part of the dump from the HSA and the second part from memory.
This is why SCSI dumps are serialized on a machine. There is only one save area for all LPARs. Normally this does not cause problems because you seldom need a dump and the HSA is locked less than a second. Should you happen on this short timeframe, you will get a pop-up window on the SE that tells you what LPAR currently uses the HSA.
The system dumper under Linux on z Systems™ is the zfcpdump command. It is part of the s390-tools package and must be prepared with the zipl tool.
The dump program determines where to put the dump. Currently, the dump program places the dump on the SCSI disk where the program resides.
The dump disk contains the dump program and a file system. The dump disk is mountable and all dumps are files. It is possible to have several dumps on one dump disk.
For more information about the dump utilities see Using the Dump Tools, SC33-8412.