Re: Migrate from AIX to Linux
Date: Wed, 16 Dec 2015 16:43:37 -0800
Message-ID: <CADsdiQjVhPyK4e45Kr3xjC57JSUGnypn3oPsoGw5_=4hCKvQGQ_at_mail.gmail.com>
I think Tim nails it completely in his online here <https://community.delphix.com/delphix/topics/cross-platform-provisioning-xpp-or-unix-to-linux-u2l-is-the-first-step-to-migrate-to-the-cloud> but
I also blogged with more detail at
http://blog.delphix.com/kyle/2014/delphix-unix-linux-oracle-conversion/
The big difference is automation, though there are some huge technical
advantages.
As an analogy, I could backup my database with the UNIX copy command (cp)
but why? I'd use RMAN. RMAN not only is much more powerful, with cool low
level functionality that I couldn't write myself, but it's automated.
Same with Delphix. You can script much of what Delphix does by hand if you
have storage system with snapshots but with Delphix it's completely
automated and there are things you probably can't code yourself such as
storing 2 versions of a database (AIX version and Linux version) in 1/3 the
size of the original database. Delphix actually maps the endianess
conversions from one platform to another using the same data for both
versions of the database and compressing that data.
Delphix is also point and click and forget about it when migrating to the
cloud. One Delphix appliance can replicate to another in the cloud with
compression, encryption, reusability and at scheduled transfer times (so as
not to flood network during high usage periods). It's much easier and
foolproof than trying to migrate the database myself.
Delphix does 3 things to help XPP
- full automation - connect to source, pull in changes, provision converted database
- export and import of system data
- reduce disk footprint required by 2-3x (i.e. in 1/2 to 1/3 the space) for initial copy, almost free for any additional copies
For me, full automation is where it's at. Just select and register source and target and click a few buttons and conversion is done automatically. That's powerful especially when the process can be slow and tedious.
IMO the biggest challenge with cross platform conversion (XPP) is complying with the restrictions for XPP. Delphix will find them, but the DBA still has to fix them.
Going from one version of Linux to another is great because there is a convert database command. Unfortunately going *NIX to Linux there is no command and it requires exporting the database general information like users and procedures etc (since with convert database doesn't work with *UNIX to Linux so you have to transfer each tablespace and then manually transfer system data you want to keep). Delphix takes care of this part automatically.
- Kyle
On Tue, Dec 15, 2015 at 4:01 AM, Tim Gorman <tim_at_evdbt.com> wrote:
> Matt,
>
> Extra work? Not for the DBA, and not when you consider that the
> "standard" RMAN approach requires three full copies (3x) of the database
> being converted...
>
>
> 1. Original database in READ WRITE on UNIX (i.e. Solaris, HP-UX, AIX)
> 2. Copy of database in READ ONLY on UNIX (a.k.a. conversion "source")
> - Creating this copy often needs to happen multiple times for TTS
> and XPP "validation"
> 3. Copy of database in READ WRITE on Linux (a.k.a. conversion
> "target")
>
>
> What Kyle describes uses about 1.3x of the size of the original database,
> not 3.0x...
>
>
> 1. Original database in READ WRITE on UNIX (i.e. Solaris, HP-UX, AIX)
> 2. dSource of database (consuming 1/3rd the size of the original
> database)
> - Copy of database in READ ONLY on UNIX (a.k.a. conversion "source")
> consuming zero bytes and 5-10 mins to create
> - Creating this copy often needs to happen multiple times for
> TTS and XPP "validation"
> - Copy of database in READ WRITE on Linux (a.k.a. conversion
> "target") consuming less than 100 GB of storage
>
>
> All of this may not matter when you're discussing cross-platform migration
> of a small database, but small databases rarely cause difficulties of any
> kind.
>
> Besides, if you've done the process "manually", then having the whole
> process employing TTS automated already should be very attractive.
>
> I've also spent some time documenting the process online here
> <https://community.delphix.com/delphix/topics/cross-platform-provisioning-xpp-or-unix-to-linux-u2l-is-the-first-step-to-migrate-to-the-cloud>,
> if that helps?
>
> Thanks!
>
> -Tim
>
>
>
>
> On 12/15/15 0:48, Dimensional DBA wrote:
>
> Seems like extra unnecessary work Kyle, than just using the standard rman
> methodology proposed.
>
>
>
> Deepak, what is your outage window allowed for this database?
>
>
>
>
>
>
>
> *Matthew Parker*
>
> *Chief Technologist*
>
> *425-891-7934 <425-891-7934> (cell)*
>
> * <Dimensional.dba_at_comcast.net>Dimensional.dba_at_comcast.net
> <Dimensional.dba_at_comcast.net>*
>
> *View Matthew Parker's profile on LinkedIn*
> <http://www.linkedin.com/pub/matthew-parker/6/51b/944/>
>
>
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Dec 17 2015 - 01:43:37 CET