Archive for June, 2008

Cleanly removing an agent or host target from Oracle Grid Control

Removing a host/agent in Oracle’s Grid Control can be unnerving: There are enough dependencies between the agent, the (cluster-)database, the listener, the host and so to make your deleting action an endless sequence if you are following them.

But GC really becomes stubborn if the agent we are about to remove is unavailable: due to the host being down or due to network connection problems. The removal jobs will be submitted successfully, but the targets will simply not vanish.

There’s a solution for both problems: Following a hint from David (thanks a lot), I finally found Metalink paper 454081.1: The quintessence is to execute

exec mgmt_admin.cleanup_agent('<port>');

as user “sysman” on your grid control repository database. (If you are removing an agent that’s still reachable, stop it before executing this one.) The package might run several minutes, but that’s perfectly okay.

It might be interesting to find out more about the capabilities of mgmt_admin – keep it in mind.

Happy cleanup,

By usn in Oracle  .::. (Add your comment)

Blocking network loopback slows down firefox extremely

My newly installed Firefox web browser (versions 2 and 3, does not matter) was deadly slow. I don’t mean the display of web sites, no, I am talking about pulldown-menus or opening tabs. (For example, bookmarks folder opens within 6 long seconds.) Several hours I was not able to tell why it acts that way. But now, I found out:

The system is protected with a host firewall. Ruleset:

iptables -t filter -F
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -t filter -A INPUT -m state \
iptables -t filter -A INPUT -j REJECT \
   --reject-with icmp-port-unreachable

But inserting this:

# Firefox seems to do stuff over loopback, 
# it's deadly slow without that setting
iptables -t filter -A INPUT -i lo -j ACCEPT

at “#mark” makes it work fast as usual.

Tell me, why are they doing ther menu communication via loopback network socket?

Just in case you might wonder, too.

Grid Control startup fails, installUser=%s_userName%

Oracle seems to have an uncommon sense of humor. Executing gcstartup after patching the grid control server to (Linux x86) fails with:

/bin/su: user %s_userName% does not exist

I am not surprised, since this is windows’ environment variable notation, and unknown to my Linux shells. Solution: In the head of




with  the username you installed grid control management services as: In my (and probably most cases) it should look like


Hope it helps

By usn in Oracle  .::. (Add your comment)

Discovered openstreetmap for me

Hi, is a very cool project. Just discovered it for me, and spent the weekend with tracking and editing my hometown by car. Have a look here to see.

I am using SportsTracker for my Nokia E90 and JOSM for the editing at home.

Also checked for TrekBuddy on the phone to use a real moving map on the cellular. Maybe you want to use a little help for generating the map files for TrekBuddy?

Still much to learn, stay tuned for reports.


EDIT: Today (18th of June) at the LUG meeting in Mitterteich will be a short talk about OSM including some practices.

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