db2 replication vs log shipping

[GB]

Hi,

I'm trying to find an easy, efficient and safe site-to-site
backup/failover solution.
The idea is to have anytime a remote copy of 99.99% of the data.

Productive db -> VPN (internet) -> Backup site
source destination
Replication:
Slows down productive db
Quite difficult to invert the replication, backup site cannot go live
then back to the normal (backup) state again

Log shipping:
Quite a lot of data can be lost since the logfile size cannot always be
reduced

Has someone here some good or bad experiences doing this ?
Any ideas about bandwidth usage ?

Thanks, Greg

[Dale McInnis]

Greg
There are several options available for Disater Recovery:

Method

Pros

Cons

Transport of database backups
Low cost

Recovery to time of last backup
Lose all transactions since last backup

Transport of database backups and archived logs (physical/network)
Recovery to time of last archived log

Low cost
Lose all transactions in the active logs

Longer recovery time (database restore followed by roll-forward
through all the logs)

Standby Database via Log Shipping
Support for no transaction loss

Minimal impact to production system
Standby not available for use while in Rollforward mode

Standby needs to be physically and logically identical

Some administrative actions not reflected on standby (eg. NOT LOGGED
operations)

Standby Database via Replication
Can read (and write) standby

Standby need not be physically and logically identical

Can choose to replicate only critical tables
Transaction loss a possibility

Extra cycles on production database for transaction capture

Some administrative actions not reflected on standby (eg. NOT LOGGED
operations)

Synchronous mirroring of all data and log disks
No transaction loss

All changes to the database (including administrative) are replicated

Shortest restart time
Performance impact of synchronous mirroring to a geographically remote
site

High price (software/hardware/network)

I would also check out the up and coming release of DB2 UDB called Stringer:
http://www-306.ibm.com/software/data/db2/stinger/

Dale McInnis


"GB" <bo********@bigfoot.com> wrote in message
news:40********@news.deckpoint.ch...

Hi,

I'm trying to find an easy, efficient and safe site-to-site
backup/failover solution.
The idea is to have anytime a remote copy of 99.99% of the data.

Productive db -> VPN (internet) -> Backup site
source destination
Replication:
Slows down productive db
Quite difficult to invert the replication, backup site cannot go live
then back to the normal (backup) state again

Log shipping:
Quite a lot of data can be lost since the logfile size cannot always be
reduced

Has someone here some good or bad experiences doing this ?
Any ideas about bandwidth usage ?

Thanks, Greg