Thursday, January 18, 2007

Some good progress

Well, we made some really good progress today with the DW conversion. We carved off 400 gig section of our SAN even before the new disks have arrived, and created a 10gR2 DB there in noarchive mode. I built a DCL script that runs on the VMS cluster and exports one table at a time from a list that we compiled to a distinct file name, then FTP's the export file to the Linux server with the new LUN mounted. Then the Linux server imports those tables into the new DB and sends a notification if there are any failures. We have created all of the tables already in the DB and spread out the tables over multiple tablespaces. This is more for our ease of management than anything performance based. The process has been running for about 7 hours now and has sent 1,079 tables with very few failures, but the big tables are still to come, with the throughput we are getting, are estimates are about 120-130 hours. The import process imports 4 files at a time as any more than that saturates the IO on the linux box. This is of course simply a test to see what will fail and give us an idea on how long we will have to book downtime for. The largest slow down is the network link between the 2 sites, we 100% utilize the network link. The network folks are going to investigate some point to point VPN's as they are confident they can get 3 or 4 dedicated ADSL lines into the remote site and our internet pipe is much larger (x10) than the dedicated network link.

I think our downtime will be limited though, The data import process can be stopped and only a select few users have rights assigned by the application to make data changes. We will remove those rights via the application, then stop the data load process and start the transfer when we do this for real. That will mean the users will be able to query the old system while the data is being transfered. The consultants have been very successful in "fooling" the application to connect to the test database on the linux server, took some work on their side though. They knew they were able to compile the application on an older HP-UX PA-RISC series running V10 of the OS, luckily we had one. On that server we were able to install an oracle 9 client which their application recognizes and will still connect to the 10g database. They have about 3 weeks of work to finish the application move to the HP-UX server though and that does not include any testing or recoding the inevitable failures. We have a consulting company coming up next week to work on converting the VMS DCL script portion of the system to unix shell scripts. That is going to be interesting working through that conversion.

Tomorrow we tackle the triggers and PL/SQL code and see what fails there. 15 hours at the office today is enough for me.



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