I have to move an oracle 8i database from one server to another server
(bigger, newer and has more RAM). I have to do it with minimum
downtime. If you have to do it, how would you do it?
Assume that the old and new servers are the same except for:
- RAM
- bigger available storage space

O/S version is newer though on the new server. I would like to hear
your ideas.

I know 8i is an old release but we have plan to migrate to 9iR2 after
the migration to the new server.

Daud

After you perform the test exercise, you'll know if your test plan
worked, how long it took to execute and if the new OS version caused
problems.

You might want to provide a little more detail, such as:
database size (GB) (e.g. 100 GB)
[ archivelog | noarchivelog ] mode (e.g. archivelog)
average redo log generation rate (e.g. 8 GB/day)
[ enterprise | standard ] edition of the database server software?
(e.g. standard)
Is any downtime allowed? (e.g. Yes - 15 minutes at cutover)
Network connection between servers [ gigabit, SAN, backup tapes + FedEx
] (GigE Full duplex)
What percent of the user tablespaces are read only (if any)? (e.g. 10%,
10 GB)
Read, write rate of source and target database storage subsystems.
(e.g. 40 MB/sec)

For the example data above, the rate limiting factor for the file copy
will be the write rate on the target system:

102400 MB / 40 (MB/sec) = 2560 sec or about 42 minutes.

If your downtime window is large enough, simply copy a cold backup set
from source to target.

If your downtime window will not allow for a cold backup set to be
used, another method would be to copy a hot backup set from source to
destination.

After the hot backup set has been transferred, the required archived
redo logs are copied.
The source database is then shutdown cleanly and then the control files
and online redo logs are copied to the target.
The hot backup set is mounted as the same database using the current
controlfiles and complete recovery is performed.
The database is then opened noresetlogs.

This would translate to a downtime window of:

shutdown time of database instance on source host
time to transfer controlfiles, online redo logs to target host
time to rename files on target host, if needed
time to recover database on target host
time to open the database instance on the source host (minimal for
noresetlogs)

that ought to get you started.
You are going to run a full test prior to the actual cutover, right?

-bdbafh

DB size: 200-250Gb
Archivelog mode
redo generation - 25Gb a day
enterprise edition (8.1.7.3)
the servers are on lan (gigabit probably)
read only tablespace - 0
Downtime: minimum ... maybe a 2-4 hours.

Can I just install oracle on the new server and patch it to 8.1.7.3 and
do a filecopy from old to new and startup oracle? Will it work since
the o/s version is different. The old server is running hpux 11.0 but
the new server will have 11i. On top of that we are trying to migrate
the storage from EMC to EVA. I am trying to find out now from the unix
admin whether the filesystem type on the new server is going to be the
same as the old one.
I have done the migration between servers of the same o/s version
before that is easy.

Daud

When you change so much, I'd alter the database version as well.
Install 9i on your fresh server, create your database using all the
nice new features of 9i, and use exp/imp for migration.
Proven technology, catch 2 birds in one strike.

My 2 c,
Frank van Bortel