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Architected Clearcase Infrastructure(s) completed with HA/DR at a

it_user747837 - PeerSpot reviewer
Consultant with 201-500 employees

Project Description

Architected Clearcase Infrastructure(s) completed with HA/DR at a time IBM Rational did not support such solutions

1st project in Glen Allen, VA: Replaced all-in-one CC server, on an end-of-life host, with registry, view, and VOB servers on 3 separate hosts. The small box hosting the registry server has a redundant fail-over server. The viewserver host is the fail-over host for the VOBserver, and vice-versa, due to budget constraints. HP ServiceGuard was the tool to switch the control of the disk arrays to the fail-over host, which would resume the DNS alias of the failed host, on top of its existing aliases. Symbolic links were used to facilitate views and VOBs move, as well as disk expansion.

2nd project in McLean, VA: 

Early phase: Fixing the ineffective HA/DR solution of 1 remote redundant host and establishing a NO-failback strategy, i.e. once fail-over is done, no fail back is necessary until a failure requiring a new fail-over. This is possible as access latency is minimal over the distance of 20 miles to remote location. 

Final phase: Expand an infrastructure of an all-in-one server host with its redundant host into one with 6 hosts, including 1 redundant host for registry server and 4 non-redundant fail-over hosts:

  • - with 2 pairs of load balanced boxes, each hosting both viewservers and VOBservers
  • - The 2 identical boxes of each pair, old pair at smaller size, are located in two different data centers.
  • - with IBM Shark SAN replicated between the 2 data centers via IBM PPRC
  • - with HA/DR fail-over achieved via re-load-balancing into the one box of the pair at the other data center with the passive replicated SAN disk partitions becoming active.

3rd project in Tarrytown, NY: 

  • - Brought Clearcase from version 3.x without maintenance license to 6.x (constrained against available 7.x) to comply with Solaris 10 required for the newer Sun CPU, embedded in the immuno-essay instrument. Created a solution for clearmake on a legacy Solaris 2.4 Sparc 20, which is required for a legacy real time HP6800 psos compiler, and which did not support Clearcase any version higher than 3.2
  • - Built ClearQuest infrastrure and implemented from the ground up to port Clear DDTS over to CQ.

Lessons Learned

For the first project: Would have used stub Unix accounts to prevent users from accessing Clearcase servers instead of the awkward restricted landing site.


Support from colleagues
earn respects
satisfaction of job well done


Management had to be convinced
small buget 1st project
no support from IBM for HA/DR

Products Used

Technical Skills Used

  • Unix shell script, Clearcase, HP ServiceGuard
  • ClearQuest, PPRC, SAN, DDTS
  • Short Pump37.6504-77.6125
  • East New York (NY-US)40.6668-73.8824
  • McLean (VA-US)38.9343-77.1775