By using this site, you agree to our updated Privacy Policy and our Terms of Use. Manage your Cookies Settings.
425,588 Members | 1,920 Online
Bytes IT Community
+ Ask a Question
Need help? Post your question and get tips & solutions from a community of 425,588 IT Pros & Developers. It's quick & easy.

System clock vs. DB2

P: n/a
Is there any issue re-setting system time while DB2 database is online
and the system clock is ahead. The database is actually a 24x7
operational and a unscheduled shutdown would be a problem.
Thanks,
-Eugene

Nov 12 '05 #1
Share this Question
Share on Google+
8 Replies


P: n/a
eu****@profitlogic.com wrote:
Is there any issue re-setting system time while DB2 database is online
and the system clock is ahead. The database is actually a 24x7
operational and a unscheduled shutdown would be a problem.
Thanks,
-Eugene

Yes. Even when db2 is stopped setting clock back may be hazardous to your health
(think recovery - point in time). How much clock is ahead?

Jan M. Nelken
Nov 12 '05 #2

P: n/a
The system clock is about 40 min ahead wich is not good to the
applications using this database instance (I'll have to fix the
timestamps in the app tables anyways at the scheduled database
meintenance time).

Nov 12 '05 #3

P: n/a
eu****@profitlogic.com wrote:
The system clock is about 40 min ahead wich is not good to the
applications using this database instance (I'll have to fix the
timestamps in the app tables anyways at the scheduled database
meintenance time).

At time T bring *completely db2 down.
Change Autostart to No (*** Test this part - no DB2 processes should be started).
Reboot.
Reset system clock to T-40.
Reboot the system.
Wait 45 minuts.
Start DB2.
Change Autostart to yes.

Jan M. Nelken
Nov 12 '05 #4

P: n/a
I also figured out an alternative solution which would be:
- Stop the database
- Start the database in quiesced mode and switch from the archival
logging to the circular one (that should reset database logs)
- Restart the database to activate noarchivelog mode
- Stop the database
- Reset system clock (I am not sure if a Linux server should be
rebooted after it's clock gets reset)
- Start the database in quiesced mode and switch back to archival
logging
- Restart the database to activate archival logging (backup will be
forced of course).

Pros: no need to ensure there is no DB2 processes running and wait for
more than 40 min.
Cons: database backup required switching from circular to archival mode

The latter is not an issue as will take no longer than 15-20 min or so
to disk in our case.

Does it seem to make sense?

-Eugene

Nov 12 '05 #5

P: n/a
Jan M. Nelken wrote:
eu****@profitlogic.com wrote:
The system clock is about 40 min ahead wich is not good to the
applications using this database instance (I'll have to fix the
timestamps in the app tables anyways at the scheduled database
meintenance time).

At time T bring *completely db2 down.
Change Autostart to No (*** Test this part - no DB2 processes should be
started).
Reboot.
Reset system clock to T-40.
Reboot the system.
Wait 45 minuts.
Start DB2.
Change Autostart to yes.

Jan M. Nelken

And make sure no DDL has been done in the 40min you'll get double.
E.g. SQL statements cannos see functions screated in the future.
Cheers
Serge
Nov 12 '05 #6

P: n/a
So, bottom line guys . . .

How to keep all clients on a server at the same time? And how to keep
all servers on a system at the same time?
I'm using Windows 2003 Server with all XP clients.

Nov 12 '05 #7

P: n/a
In article <11**********************@f14g2000cwb.googlegroups .com>,
Stanley Sinclair (st*************@bellsouth.net) says...
So, bottom line guys . . .

How to keep all clients on a server at the same time? And how to keep
all servers on a system at the same time?
I'm using Windows 2003 Server with all XP clients.


You can define the 2003 server to act as the internet time server
which you can define on the XP clients. Check the XP help for
additional info.
Nov 12 '05 #8

P: n/a
Put a radio-controlled clock or other such hardware on the W2K3 server and
make it a time service provider. You can also use an internet time service
provider if you prefer, but the dedicated hardware is better.

Configure the XP clients to use the W2K3 server as their time service
provider.

The w32tm command is used for both functions.

If you're using DHCP for the XP client, you just define the W2K3 server as
the time server (option 004) in the DHCP. You can also define your time
offset there too (option 002). That way, you don't have to manage all the XP
clients separately.

"Stanley Sinclair" <st*************@bellsouth.net> wrote in message
news:11**********************@f14g2000cwb.googlegr oups.com...
So, bottom line guys . . .

How to keep all clients on a server at the same time? And how to keep
all servers on a system at the same time?
I'm using Windows 2003 Server with all XP clients.

Nov 12 '05 #9

This discussion thread is closed

Replies have been disabled for this discussion.