DASD controllers, such as the IBM 3990 and 3880's.
Line printers, such as the IBM 3900
Tape drives such as the IBM 3480, and 3490
Communication controllers, such as the IBM 3745 unit
SNA display controllers such as the 3174
S/390 DASD Attachment
Direct channel connection of the IBM S/390 Integrated Server to S/390 ESCON
DASD devices is supported.The S/390 Serial Channel Adapter must be used
for this function.
Restrictions when using the S/390 ESCON Channel Adapter
Only specific IBM devices have been tested.Because of timing
considerations, non-IBM implementations of these devices may not
DASD attachment is only supported on ESCON Serial Channel adapters.
A maximum of two ESCON adapters is supported.
Only ESCON channel functions are supported. ESCON to Parallel
converter and CTC function is not supported, however a S/390 Serial
Channel adapter can connect to another S/390 system where the CTC
“load” is in that system's channel.
Multi-path is not supported (two channels to same device controller).
S/370, S/390 DASD migration to internal disk storage
In some cases, migration of existing S/370 or S/390 DASD to the S/390
Integrated Server's internal emulated DASD is favorable.Standard
Dump/Restore programs should be used to accomplish this.
If the source DASD is ESCON attached to the IBM S/390 Integrated Server
then a program such as DFDSS can be used to copy the data from the
ESCON attached DASD to the emulated DASD on the IBM S/390 Integrated
Server without the intermediate step of dumping the DASD volume to tape.
If the source DASD has a prallel attachment to another S/370 or S/390 system,
then the DASD must be first dumped to tape, then restored to the emulated
DASD on the IBM S/390 Integrated Server using standard dump/restore
The IBM S/390 Integrated Server has sixteen internal Hot/Swap drive bays,
each of which can accommodate an 18GB disk drive.The normal configuration
will include up to sixteen 18GB disk drives providing approximately 255GB of
useable disk capacity in a RAID 5 configuration.To provide enough read/write
access mechanisms to maintain good performance, at least five active drives
are recommended to be configured for each IBM S/390 Integrated Server.
Using less than five active drives may seriously limit the disk I/O performance
of the system.
Additionally, you may be able to split your workload across multiple IBM S/390
Integrated Servers.Analysis is needed to determine if workloads and data can
be logically divided between an existing system and the IBM S/390 Integrated
Chapter 7.Planning Guide23
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