Re: Migrating from VMS to NT Server

"Artful Dodger" <oradba_at_nospam.answerdude.net> kirjoitteli seuraavaa:

>Our customer is considering a migration option which involves getting rid of
>their seventeen Dec Alpha 2000 servers running Oracle 8.1.7 on OpenVMS and
>replacing them with NT servers. They are considering this option for what
>they say are "supportability reasons". From the few people I've spoken to on
>the subject, I personally think they may be making a mistake, but while I
>may have some input, the decision is not mine.

NT is also dying breed, already desupported by both Oracle and Microsoft, so that kind of migration won't help much.

From that point of view, XP might be a better solution.

(I would use Linux on same hardware, but that's me. ;) )

>The customer has requested information from me with regard to the level of
>effort required to perform the migration. While I have done VMS and Oracle
>version upgrades, I have never actually migrated an Oracle database across
>operating systems.

I have, twice actually. First from DOS (Oracle 5) to NT (Oracle 7) and later from NT to Linux (Oracle 8.0.5). Latest upgrade was from 8.0.5 to 8.1.7 and that wasn't hard.

Worst troubles in migration were both times from different character sets, especially characters outside of 7-bit ASCII, ie. scandinavic letters ö and ä (oe, oa).

>Has anyone actually been involved in transferring an Oracle database from a
>VMS platform to an NT platform? Without knowing anything, I would think it
>would be enough to install the RDBMS on the NT server, duplicate the
>tablespaces which exist on our Alpha, then do a full database export (EXP)
>from the Alpha and import into the NT. Will this work?

Might work, but if you do also upgrade Oracle (I hope you do use current version on NT), it might be better just to export user data.

> Are there any
>pitfalls I should watch out for? (Perhaps weird character translations
>between platforms or something?)

Definetely. You could choose same character set than VMS on NT, but I suspect it will bring more trouble later than doing the conversion while migrating.

> If you have actually done this conversion,
>I'd love to hear how it went, especially as far as avoiding any mistakes you
>may have made, or things which, if not done correctly, will bite me in the
>ass later...

Create tablespaces and users before import and associate users to right default tablespaces.

If you don't

a) import can't create tables (tablespace missing) or 
b) table privileges can't be granted (to non-existent users)  or
c) some user tables in system tablespace (default for new user)

Might be other pitfalls, but I don't remember more than those.

Tuomas

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