Informix

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix

You will have to create backup i.e.
ontape -s -L 0 -t STDIO > backup.ontape
Stop instance i.e.
onmode -ky
And finaly do restore with chunk rename
cat backup.ontape | ontape -r -t STDIO  –p old_path -o oldo_ffset -n new_path -o new_offset

Or you can try sth like this:
https://www.oninitgroup.com/faq-items/informix-storage-migration-via-mirroring/

HTH

Hrvoje

------------------------------
Hrvoje Zokovic
------------------------------

Original Message:
Sent: Wed March 23, 2022 08:30 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix

Gary:

The redirected restore will work, however, there is another option. If you are using v14.10 you can use mirroring to relocate the chunk. Just create the new file empty, add the new file as a mirror of the existing chunk(s) and wait for the sync to complete. Once the mirror chunks are all active you can switch the status of the primary and mirror chunks then drop the original (now mirror) chunks and once that's done you will be able to delete the original chunk file.

The way to switch chunk roles is an SQL API function:
execute function sysadmin:task( "modify chunk swap mirror", <chunk number> );

Example:

EXECUTE FUNCTION sysadmin:task("add mirror", "newdbs", "/prod1/IFX_CHUNKS/chunk5", 0, "/prod8/IFX_CHUNKS/chunk1", 0);
select chknum from sysmaster:syschunks where fname = "/prod1/IFX_CHUNKS/chunk5"; EXECUTE FUNCTION sysadmin:task("modify chunk swap_mirror", "12");
EXECUTE FUNCTION sysadmin:task("stop mirroring","newdbs");

One caveat: If the dbspace containing a chunk has multiple chunks you have to mirror all chunks in that dbspace. So not practical if the chunk you need to move is one of many in a dbspace.

------------------------------
Art S. Kagel, President and Principal Consultant
ASK Database Management Corp.
www.askdbmgt.com
------------------------------

Original Message:
Sent: Wed March 23, 2022 08:30 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix

Original Message:
Sent: 3/23/2022 8:30:00 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix

Many thanks to everyone, great suggestions.  I will give the backup/restore a try.  I am on 12.10 but will keep the mirroring in mind for the future.

------------------------------
Gary McNair
------------------------------

Original Message:
Sent: Wed March 23, 2022 08:30 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix

Hi, I can confirm (at least on Unx/Linux systems) that a symbolic link would work, even if you change from a 
raw device to a cooked file, keeping the path.
Shut down DB, move the file, create the symbolic link from old location and restart DB (check access rights).

Ontape would also work, with rename option.
I would try to perform an external restore with ontape -p -e, followed by the rename option, which might work 
in place.
Depending on the size of DB, a backup/restore might produce a too long downtime.
-> make a L0 backup (just to make sure you are able to recover first)
-> shutdown DB cleanly with onmode -ukcy
-> rename your chunk file on OS level
-> ontape -p -e -rename ......
DB should be starting, resulting in recovery mode, you need to change mode afterwards to online with onmode -m
I think I tried something like that a while ago, could be the way with the smallest downtime if mirroring is no option,
which would possibly work with no downtime, while needing double space temporarily.

Good luck

------------------------------
Marcus Haarmann
------------------------------

Original Message:
Sent: Thu March 24, 2022 11:55 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Many thanks to everyone, great suggestions.  I will give the backup/restore a try.  I am on 12.10 but will keep the mirroring in mind for the future.

------------------------------
Gary McNair

Original Message:
Sent: Wed March 23, 2022 08:30 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix

Original Message:
Sent: 4/4/2022 4:28:00 PM
From: Marcus Haarmann
Subject: RE: renaming a chunk file pathname

Hi, I can confirm (at least on Unx/Linux systems) that a symbolic link would work, even if you change from a 
raw device to a cooked file, keeping the path.
Shut down DB, move the file, create the symbolic link from old location and restart DB (check access rights).

Ontape would also work, with rename option.
I would try to perform an external restore with ontape -p -e, followed by the rename option, which might work 
in place.
Depending on the size of DB, a backup/restore might produce a too long downtime.
-> make a L0 backup (just to make sure you are able to recover first)
-> shutdown DB cleanly with onmode -ukcy
-> rename your chunk file on OS level
-> ontape -p -e -rename ......
DB should be starting, resulting in recovery mode, you need to change mode afterwards to online with onmode -m
I think I tried something like that a while ago, could be the way with the smallest downtime if mirroring is no option,
which would possibly work with no downtime, while needing double space temporarily.

Good luck

------------------------------
Marcus Haarmann
------------------------------

Original Message:
Sent: Thu March 24, 2022 11:55 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Many thanks to everyone, great suggestions.  I will give the backup/restore a try.  I am on 12.10 but will keep the mirroring in mind for the future.

------------------------------
Gary McNair

Original Message:
Sent: Wed March 23, 2022 08:30 PM
From: Gary McNair
Subject: renaming a chunk file pathname

Hello,

I have a chunk file that I want to move to a different directory.  This is not the online_root file, just a different file that holds a few dbspaces.

After doing some searching, I found a page on the IBM support site that says this can be achieved during a restore with 'ontape'.

ontape –r -rename –p old_path -o oldo_ffset -n new_path -o new_offset

Our DB's are transactionless, our TAPEDEV and LTAPEDEV=/dev/null  (Linux).  So I don't understand what I can restore from, and would prefer not to do a restore.

Thanks for any advice,
Gary

------------------------------
Gary McNair
------------------------------

#Informix