Windows or *NIX?

I’ve found very interesting the discussion on started from a migration question and continued on a comparison between Windows and Linux or Unix, at least as Oracle platforms. The battle ended with yet another no-winner contest. What the posters say is for me very interesting. The OS religious wars are really a no-sense, but a lot of things in this world are no-sense, also me writing here.

So, i’m back to what Tom has already said: there is no a better os, you must choose that with wich YOU are more comfortable, there are no other scientific and absolute motivations to prefer one over another. I feel better with Linux, but i’ve learned a lot of things about Windows that make me better.

Personally i’ve to say that Windows has good performance, but Oracle threaded architecture on Windows it seems not so good as multi-process architecture on Unix.

Pro-Unix i want remember always a more consolidated architecture. (Unix is here from 1970 🙂 )


RAC Virtual IP

At first installation of Oracle 10g RAC which i’ve seen, made by an Oracle consultant about two years ago (version on Linux Suse EL on x86_64 platform) , the network configuration of Operating System were as this:

eth0: private interconnection interface
eth1:”public” interface

apart from the fact that also with 10.2 release VIPCA complains that “public” interface has not a pubblic class IP, i’ve noticed another problem that i don’t know how to resolve: virtual IP is being created on first interface without possibility to change it, that is “eth0” that is the private interface. In a correct configuration such interface would be connected to a switch with other private interfaces of other nodes of the cluster, separated from “public” network to which would be connected “public” interface. With such architecture i would have:

eth0: private interconnection interface
eth1:”public” interface

VIP on eth0, on network card attached on private switch, not reachable from clients connected to public switch. NO GOOD. The only workaround that i’ve found is to reconfigure operating system (in new installations) to put private ip on lower interfaces (eth0) and public IP on higher interfaces.

Do anybody know a remedy for my first installation? Note, in that installation all interfaces are connected to the same switch and so all goes well. Something is not as high available as it may be, there are not redundant network interfaces.

hwclock and date

We use RAC with Linux, Standard Edition RAC, 10g with 2 nodes with no more than 2 CPUs per machine. Today i’ve encountered a systemistic anomaly. Some time ago i’ve noticed that time in a RAC instation was different between the two nodes. SO is Linux Suse EL 9. System administrator did not configured a sincronization mechanism for time so during a downtime period i manually setted time of one server “equal” to that of the other with “date” command. This morning someone rebooted (it really was a black-out) the machines and in /var/log/messages of one machine i’ve noticed a 20 minutes lag back in time:

5:45 ..
5:49 ..
6:02 ..
5:41 ..

And so i’ve remebered what i’ve already noticed with my test of RAC installation on VMWARE virtual machines
System Clock is not Hardware Clock. When linux boots, it sets system time equals to hardware time and then it may diverge. So the moral is; use hwclock