Hi, group

today i found another problem about my informix. The ROOTPATH pointed
to /dev/dbroot instead of /dev/rdbroot. in the manul, however, i see
the chunks should be in a raw device.

is this a problem? can i simplely correct the ROOTPATH to
/dev/rdbroot with text editor and a reboot?

-
steven (AT) lczmsoft (DOT) com

Hi Steven.

It seems problem that you use Blocked device.

Do you mean as bellow ?

% ls -l /dev/rdbroot
crw-rw---- .......

% ls -l /dev/dbroot
brw-rw---- .......

If so, anyone can write on /dev/dbroot.
/dev/dbroot is file system.

It is not simple to change the ROOTPATH.

I think the better solution is dbexport -ss your database, initialize your
IDS, then dbimport.
Probably it exists more better solution than I mentioned.

Regards.

--
Tsutomu Ogiwara from Tokyo Japan.
ICQ#:168106592





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sending to informix-list

It "shouldn't" cause you any problems. You could just link /dev/dbroot
to /dev/rdboot if you want. However you can't just edit the config
and restart it will get a bit annoyed

steven wrote:
--
Paul Watson #
Oninit Ltd # Growing old is mandatory
Tel: +44 1436 672201 # Growing up is optional
Fax: +44 1436 678693 #
Mob: +44 7818 003457 #
www.oninit.com #

In message <3F6174E7.5B1C371A (AT) oninit (DOT) com>, Paul Watson <paul (AT) oninit (DOT) com>
writes
From the school of 'if it ain't broke...' I'd suggest that if it isn't
actually causing you a problem (and I don't know anything about your
configuration or application), then leave it alone. It may not represent
an optimal configuration, but whether you 'need' to do anything is up to
you. Just put it on the list of things you'd do different next time...

--
Andrew Lennard andy (AT) kontron (DOT) demon.co.uk

"Tsutomu Ogiwara" <tsutomu_ogiwara (AT) hotmail (DOT) com> wrote

Yes!

system create on /dev/dbroot.

my ROOTSPACE variabe only refer to a symbol link to real /dev/dbroot.
can i simply correct the symbol link to /dev/rdbroot w/o disturb my
data?

Why didn't you say so in the first place? :-)
Yes, you can do that. Obviously you must shut the database server down
whilst you break and re-create the link

--
Neil Truby t:01932 724027
Director m:07798 811708
Ardenta Limited e:neil.truby (AT) ardenta (DOT) com

steven (AT) steven4u (DOT) net (steven) wrote in message news:<1e7ef8d0.0309120258.677d82f3 (AT) posting (DOT) google.com>...
I am a bit confused here. You start off by saying your root points to
/dev/dbroot but further on in the discussion you claim it points to a
symbolic link. I **GUESS** you mean to say that your onconfig points
to a symbolic link, but your simbolic link points to /dev/dbroot
instead of /dev/rdbroot?

In that case it *MIGHT* be a problem if you simply change to link from
/dev/dbroot to /dev/rdbroot. WHY? you ask? Well because data is stored
differently on /dev/dbroot (which is as Tsutomo Ogiware pointed out a
block device) than on /dev/dbroot (which a raw device). What is the
difference? Block devices use the OS file IO system and raw devices to
not.

So, in short. TO BE SURE: perform a full dbexport your instance. THEN
(!) shutdown your instance, change the link (and make sure onconfig
point to it!) and restart your instance. If it goes wrong you will
have to recraate you instance with the proper link in place and
perform a dbimport. Make sure you recreate you instance in accordance
with your dbexport sql file!

Succes
Robert A. Reissaus
Ibm/Informix consultants
RISDI (tm)(r)
Amsterdam , the Netherlands
r.a.reissaus (AT) risdi (DOT) com
www.risdi.com

Neil Truby wrote:
Or execute the command very very quickly:-)

--
Paul Watson #
Oninit Ltd # Growing old is mandatory
Tel: +44 1436 672201 # Growing up is optional
Fax: +44 1436 678693 #
Mob: +44 7818 003457 #
www.oninit.com #

On Fri, 12 Sep 2003 09:07:37 -0400, Robert A. Reissaus wrote:
<SNIP>
NO THERE IS NO DIFFERENCE IN THE PHYSICAL STORAGE regardless of whether you
read/write /dev/dbroot or /dev/rdbroot. The ONLY difference is that the latter
does not go through the OS buffer cache and the former does. The data on disk
is identical either way. IT IS PERFECTLY SAFE to just bring the engine down,
remove the symbolic link to /dev/dbroot and replace it with an identically
named symbolic link to /dev/rdbroot!

HOWEVER, there is no harm, and much peace of mind to be gained from taking a
level 0 archive before going through this. Any DBA worth his salt would do so
and since you are not hurting performance wise there is no harm in taking the
time to do so.

UNNECCESSARY!

Art S. Kagel

"Art S. Kagel" <kagel (AT) bloomberg (DOT) net> wrote

This of course is abslutely true. And i stand corrected for this dum
error on my part.
Robert A. Reissaus


IT IS PERFECTLY SAFE to just bring the engine down,
This how ever I do not agree with. Changing the symbolic link will
result in error :

Cannot open chunk '/opt/DBA/Informix/Links/730/risdi08/primary/root'.
errno = 19
oninit: Fatal error in shared memory initialization

because the (old) link itself is stored in the instances systam
tables. So it would not be sufficient to 'simply' change the link.
Robert A. Reissaus

I usually do a dbexport of a (smaller) instance because it is (imo)
sometimes easier to rebuild a instance in case anything goes wrong
than to do a restore specifically after having tried to do what is
attempted here. So I would find the *UNNECCESSARY!* a bit too strong
(especcially in caps).

Robert A. Reissaus