New to Db2 - installation question

[scottgamble]

My company is making the switch to DB2 from Oracle. I have been working
with Oracle for the last 10 years or so and still very very new to DB2.

One question that has come up recently within our team is the location
of the software. It appears that at a minimum there has to be a link to
/usr/opt/something (Off the top of my head I do not recall the exact
directory).

Using db2_install it appears (from the doc) that you can specify an
alternate directory for the location of the software however you are
still going to get the link to /usr/opt.

Is my understanding correct?

If that is the case it would seem its not possible to install seperate
copies of the software/binaries if you wanted to put a second instance
on a machine. They are always going to share the link in /usr/opt and
thus be using the same software. Which really eliminates one of the
reasons you would have a second instance (upgrading them seperately).
Sure you could just use a second machine but the direction of this
company has been to use fewer bigger servers.

The reason this came up was due to a question about clustering 2
database servers in an active/passive manner ( I believe the db2 doc
refers to this is a hot standby). We might have 2 or more instances on
1 cluster (see above fewer bigger machines) that potentially could be
running on 1 machine. Seems this is doable but with only 1 copy of the
software because of the /usr/opt link.

The argument then comes up are multiple instances on the same
instance/cluster really a good idea.

Hope this makes sense I havae been reading a lot of DB2 documentation
and have a lot of terms spinning in my head (Not to mention the Oracle
to Db2 terms that are differant).

Scott

[scottgamble]

sc*********@com cast.net wrote:

My company is making the switch to DB2 from Oracle. I have been working
with Oracle for the last 10 years or so and still very very new to DB2.

Snipped a bunch of stuff in the previous post

Sorry I guess I should mention OS and versions in case it makes a
difference.
OS is Aix and 8.2 of DB2.

[Serge Rielau]

sc*********@com cast.net wrote:

sc*********@com cast.net wrote:

>My company is making the switch to DB2 from Oracle. I have been working
with Oracle for the last 10 years or so and still very very new to DB2.

Snipped a bunch of stuff in the previous post

Sorry I guess I should mention OS and versions in case it makes a
difference.
OS is Aix and 8.2 of DB2.

In DB2 V8.2 on AIX you can have an alternate install path.
This is a lot simpler in DB2 9. You can install as many copies of DB2
with different paths and release levels as you wish.

Cheers
Serge

--
Serge Rielau
DB2 Solutions Development
IBM Toronto Lab

IOD Conference
http://www.ibm.com/software/data/ond...ness/conf2006/

[Mark A]

<sc*********@co mcast.netwrote in message
news:11******** **************@ m73g2000cwd.goo glegroups.com.. .

My company is making the switch to DB2 from Oracle. I have been working
with Oracle for the last 10 years or so and still very very new to DB2.

One question that has come up recently within our team is the location
of the software. It appears that at a minimum there has to be a link to
/usr/opt/something (Off the top of my head I do not recall the exact
directory).

Using db2_install it appears (from the doc) that you can specify an
alternate directory for the location of the software however you are
still going to get the link to /usr/opt.

Is my understanding correct?

If that is the case it would seem its not possible to install seperate
copies of the software/binaries if you wanted to put a second instance
on a machine. They are always going to share the link in /usr/opt and
thus be using the same software. Which really eliminates one of the
reasons you would have a second instance (upgrading them seperately).
Sure you could just use a second machine but the direction of this
company has been to use fewer bigger servers.

The reason this came up was due to a question about clustering 2
database servers in an active/passive manner ( I believe the db2 doc
refers to this is a hot standby). We might have 2 or more instances on
1 cluster (see above fewer bigger machines) that potentially could be
running on 1 machine. Seems this is doable but with only 1 copy of the
software because of the /usr/opt link.

The argument then comes up are multiple instances on the same
instance/cluster really a good idea.

Hope this makes sense I havae been reading a lot of DB2 documentation
and have a lot of terms spinning in my head (Not to mention the Oracle
to Db2 terms that are differant).

Scott

DB2 has the following installed "components " on UNIX or Linux install:

- Installed binaries for the base code without any fixpack (use the default
directory to save yourself some grief).

- Fixpacks installed on top of the base code. If you do not use alternate
fixpacks (available with ESE only) then all fixpacks update the base code
and all instances are at the same fixpack level (unless you are running two
different versions such as 8.1 and 9.1).

- Alternate Fixpacks. If you have ESE and use alternate fixpacks, the
alternate fixpack installs on a different directory than the base code to
enable you to choose which fixpack to use with which instance. Let DB2
install choose the install directory.

- Instance - A DB2 instance is not a separate install of the binaries. You
can easily create multiple instances on a server, and this may be a good
idea for many reasons. Each instance has symbolic links to the binaries you
are using (wither the base code updated by any fixpacks, or alternate
fixpacks if you chose that method). Each instance can be a separate release
or fixpack (if you use alternate fixpacks). What determines the
release/fixpack level of the instance is what directory path you use to
create the instance from (if you are using alternate fixpacks or have
different major release levels installed). So you can have multiple
instances even though they all point the same binaries via symbolic links.
For simplicity, the instance is "created" on the home directory of the
instance owner user id (you may need to create the user id in advance unless
you use the GUI install). When you create an instance, DB2 will update the
user profile of the instance owner to automatically point to the instance
named by that user id when that user first logs on. Other local users who
logon to the database server directly must have the profile created for them
manually (remote users just need the appropriate client).

- Database - You can create one or more databases in each instance.

Now to your other question. Based on your need for a standby database
server, I would look at HADR, which is included for free with ESE and priced
separately for WSE, and Express versions. Check out the "Data Recovery and
High Availability Guide and Reference."

[Mark A]

"Serge Rielau" <sr*****@ca.ibm .comwrote in message
news:4j******** ****@individual .net...

In DB2 V8.2 on AIX you can have an alternate install path.
This is a lot simpler in DB2 9. You can install as many copies of DB2 with
different paths and release levels as you wish.

Cheers
Serge

--
Serge Rielau
DB2 Solutions Development
IBM Toronto Lab

Unless one is using DPF, I don't know of any good reason to not use the
default install path.

I don't care what software you are installing, sooner or later the gods will
seek their revenge for not using the default install path.

[awtmbi]

Just add on to Mark's comment, DB2 UDB family packaging can be obtained
from Paul's dW article --
http://www-128.ibm.com/developerwork...kopoulos1.html

[scottgamble]

Sorry I guess I should mention OS and versions in case it makes a

difference.
OS is Aix and 8.2 of DB2.

In DB2 V8.2 on AIX you can have an alternate install path.
This is a lot simpler in DB2 9. You can install as many copies of DB2
with different paths and release levels as you wish.

Cheers
Serge

--

>From what you said it sounds like its possible with 8.2 but does that

still force the link to /usr/opt/XXXX?

Some of the other comments hinted at it not being a good idea to vary
from the default installation path.

Can anyone expand on that a bit more of why its a bad idea (Keeping in
mind I am still new to DB2 and struggling with the terms a little
bit.). A pointer to the correct documentation would be fine as well. I
have struggled with the documentation and finding what I am looking for
although I am getting better
Scott

[Darin McBride]

sc*********@com cast.net wrote:

Sorry I guess I should mention OS and versions in case it makes a
difference.
OS is Aix and 8.2 of DB2.

In DB2 V8.2 on AIX you can have an alternate install path.
This is a lot simpler in DB2 9. You can install as many copies of DB2
with different paths and release levels as you wish.

Cheers
Serge

--

From what you said it sounds like its possible with 8.2 but does that
still force the link to /usr/opt/XXXX?

First, a bit of background. The ability to install somewhere other than the
default path is only available to Solaris with DB2 v8, with the limitation
of the default install path being a symlink to the real install path. This
ability was developed for all platforms in DB2 v9, and the limitation
removed simultaneously.

Back to v8. You can install the "regular" version of the product, which is
fully upgradable via fixpak. As you're on AIX, there is no option as to
where it gets installed: it goes in /usr/opt/db2_08_01. (There is a
symlink whitepaper for v7 which applies to v8 as well, if you search for it
on IBM's website, but all it does is show you how to do what is already
being done on Solaris.)

If you're using ESE, you can use "alternate" fixpaks (AFP). With AFP, you
install a new copy of DB2 at a particular fixpak level. It goes into a new
path (/usr/opt/db2_08_FP#). The AFPs cannot be directly upgraded via
fixpak. Instead, you will need to install the new AFP to its new install
path, and then use db2iupdt from the new install path to update the
instance to the new base path, which will reset its symlinks, and thus
upgrade the instance. You can also use db2iupdt to reset an instance back
to the main path, if you have anything installed there (some DB2 users do
not bother with the main install path).

Note that AFPs have a few restrictions, too. Primary among them is a lack
of support for anything that isn't ESE. So, if you want to use Websphere
Information Integrator, or DB2 Query Patroller, or DB2 Text Extenders,
well, AFP is not for you.

Some of the other comments hinted at it not being a good idea to vary
from the default installation path.

You can't really do that in v8 anyway. In v9, it's fully supported, and as
long as you use the DB2-owned installation methods (there are 4 methods of
installation, one of which is a manual install, the other three are
automated to varying degrees, and thus a bit more reliable), I see no
reason why you shouldn't use the paths you want as appropriate.

Can anyone expand on that a bit more of why its a bad idea (Keeping in
mind I am still new to DB2 and struggling with the terms a little
bit.). A pointer to the correct documentation would be fine as well. I
have struggled with the documentation and finding what I am looking for
although I am getting better

As you are just looking at moving to DB2 now, my suggestion would be to
start with DB2 v9. Though v8 will continue to be supported for some time,
the Oracle concept of installing a bunch of copies to have individual
upgrade options was implemented in DB2 v9. You can still have multiple
instances set up pointing to a single copy of DB2, but you'll no longer be
tied to that the way that v8 was.