Browse Prior Art Database

Automatic IPL Drive Switch

IP.com Disclosure Number: IPCOM000113024D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Oka, Y: AUTHOR

Abstract

Disclosed is a logic for automatic IPL drive switch for PS/55 & FIS-90 (Finance Industry Solutions for the '90s). This logic adds an automatic IPL drive switch function from failed primary HDD to secondary HDD for high availability PS/55 requested from finance industry market.

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Automatic IPL Drive Switch

      Disclosed is a logic for automatic IPL drive switch for PS/55 &
FIS-90 (Finance Industry Solutions for the '90s).  This logic adds an
automatic IPL drive switch function from failed primary HDD to
secondary HDD for high availability PS/55 requested from finance
industry market.

      Fig. 1 shows the example of this logic.  HDD1 and HDD2 have a
same size and a same data set as; OS, application program and user
data.  HDD1 and HDD2 have SCSI ID select logic and both HDD ID select
logic are connected to the switching circuit in the Remote Power
Control Card (RPCC).  The ID switching circuit can switch the HDD ID
from 6 to 5 (HDD1) and 5 to 6 (HDD2).  The RPCC which is normally
powered from sub-power supply has main power -ON/+OFF function, above

ID switch function and IPL complete signal receiver.  This card
constructs micro processor, ROM, RAM, timer etc.,  devices, works as
control processor card.  A Micro Channel* Adapter in this case called
KBD/RAS adapter has IPL complete signal decoder, which decodes I/O
write signal and I/O select signal to IPL complete signal.  This IPL
complete signal is issued by application program at user application
start.

Fig. 2 shows flow chart of this switching logic work.

1.  At main power on by RPCC, the RPCC start a presettable timer to
    watch the IPL complete signal receive time.

2.  PS/2, PS/55 system planer starts the power on self test

3.  After power on self test completion, S...