i want to ask to forum that i want to exact diffrences between ontape and onbar commands.and why we use that different two commands for backups.

What rae the purposes of the usage of these two diffrent commands?

First of all: ontape writes directly to tape and is user interactive.
This is the easiest solution to make backups.
But it cannot run in the crontab. It needs user input.
Onbar uses the xbsa interface to talk to a storage manager. The storage manager writes the data to tape.
You must configure the storage maneger properly.
Onbar is not user-interactive.
onbar is able to do parallel backups.
You can define several streams to write simultaneously to a storage manager.
The default storage manager is ISM (Informix Storage Manager), it is delivered with the product.

By the way: There is always onarchive too. Yet another way to do backups... This is very old though.

in the case of recovering database,which one you advice me,ontape or onbar? what are the pros onbar have on ontape? with ontape can we rstore dbspaces or tables in micro level?

Ontape is by nature interactive, but it is possible to run it from cron

E.G.

###########
# foo.sh

ontape -s -L0 <<FOO 1>/var/log/backup 2>&1

FOO
###########

What if the arhive file grows too big, > 2 GB ??
set TAPEDEV to a pipe file and gzip its contents to another file while ontape runs.

Of course, there is no problem when trying to recover an entire DB archived with ontape

just issue ontape -r

greetz

What I means was: ontape is never supposed to run in a cron; usually ontape is used to write directly to a tape device. When the tape is full, ontape will ask you to put in another tape and will wait.
This is just an example why ontape should not run in the cron.

You cannot do table-level restores, unless you put one table per dbspace and do a dbspace restore.

onbar is the way to go: a little bit more difficult to configure, bt once configured it runs like a charms. parallel backups, netbackups, you name it.

is there a change with 'onbar' or 'ontape' to restore a crashed chunk at the Chunk level?

You cannot do a chunk level restores. You can do a dbspace restore.
In this case there is no difference between onbar and ontape.

All depends what tool you used to create the backup/ You must use the same tool to do the restore.

I was able to retore the dbspace on my staging environment using ontape command but I am no able to do the same on my systest environment. I am getting following error:

"Physical restore failed - Bad log file configuration for log 1."






Following is the output of the existing dbspace on systest environment:
Dbspaces
address number flags fchunk nchunks flags owner name
a22a100 1 1 1 1 N informix rootdbs
a22a6f0 2 1 2 1 N informix ifam
a22a760 3 1 3 1 N informix temp1
a22a7d0 4 1 4 1 N informix ifam2
a66c080 5 5 5 1 ND informix ifamdbs
a22a840 8 1 8 1 N informix ifamsi
a22a8b0 9 1 9 1 N informix ifamy2k
7 active, 2047 maximum

Chunks
address chk/dbs offset size free bpages flags pathname
a22a170 1 1 0 10000 2754 PO- /dev/vx/rdsk/ifamdg/vol-informix-root
a22a2b8 2 2 0 153600 120736 PO- /dev/vx/rdsk/ifamdg/vol-ifam
a22a390 3 3 0 500 447 PO- /home/informix/tmp1
a22a468 4 4 0 307200 292421 PO- /dev/vx/rdsk/ifamdg/vol-ifam2
a66da50 5 5 0 1024000 1023947 PD- /dev/vx/rdsk/ifamdg/vol-ifamdg-ifamdb
a22a540 8 8 0 76800 72924 PO- /dev/vx/rdsk/ifamdg/vol-ifamdg-mifamsi
a22a618 9 9 0 76800 41644 PO- /dev/vx/rdsk/ifamdg/vol-ifamdg-ifamY2K




The way I am restoring it is :
ontape -r -D ifamdbs

Please mount tape 1 on /infdump/infdb/backup.dmp and press Return to continue ...

Archive Tape Information

Tape type: Archive Backup Tape
Online version: INFORMIX-OnLine Version 7.24.UC5
Archive date: Wed Nov 6 03:53:07 2002
User id: informix
Terminal id: ?
Archive level: 0
Tape device: /opt/inf/inf_p01_db
Tape blocksize (in k): 16
Tape size (in k): 50000000
Tape number in series: 1
Continue restore? (y/n)y

Spaces to restore:1 [ifamdbs ]
Physical restore failed - Bad log file configuration for log 1.


Program over.




Could you please help me out ? Thanks,

Do you have your logical and physical logs in the rootdbs. Not a good idea. I do not see them in the restore paramaters.

I thing it require logical log tape to restore with physical restore of ifamdbs