onbar Level 0 backup question
The poster asked whether "onbar -b -L 0" re-backs-up a dbspace that hasn't changed since the last level-0 backup. Answer: yes — a level 0 is a full backup of all used pages in every dbspace, regardless of prior backups, and is self-sufficient for restore; use -L 1 for incrementals of changed pages only. It was also explained that a normal level-0 doesn't back up logical logs (those need separate "onbar -b -l" and must be restored too), whereas a whole-system backup (onbar -b -w) uses a single archive checkpoint and includes the needed log records, so it restores without log restores. Question resolved.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Hi All,
as usual i'm using "onbar -b -L 0" to backup my DB.. if i've done a level 0
backup which means, i'm backing up all devices except logical logs... My
question is, If DBspace1 successfully backed-up and no change made, does the
"onbar -b -L 0" backup again the DBspace1?.
Yes. A level 0 backup will backup all of the used pages on a space regardless
of any previous backups. I think that you will also find that your logical
logs will also be backed up.
If you want to only backup changes since the last level 0 backup, then use an
incremental backup onbar -b -L 1. This will backup all pages changed in the
spaces since the last level 0 backup
> To: ids@iiug.org
> From: informix2009@gmail.com
> Subject: onbar Level 0 backup question [17583]
> Date: Thu, 15 Oct 2009 05:12:04 -0400
>
> Hi All,
>
> as usual i'm using "onbar -b -L 0" to backup my DB.. if i've done a level 0
> backup which means, i'm backing up all devices except logical logs... My
> question is, If DBspace1 successfully backed-up and no change made, does the
> "onbar -b -L 0" backup again the DBspace1?.
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
_________________________________________________________________
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ics.aspx?ocid=PID23461::T:WLMTAGL:ON:WL:en-za:SI_SB_3:092010
Hi,
there's a difference between "normal" level-0 backup
("onbar -b -L 0") and "whole system" level-0 backup
("onbar -b -w [-L 0]").
The normal level-0 backup will always backup all dbspaces,
no matter whether there was change or not. But it will not
backup the content of logical logs, because it assumes that
they are backed up separately by "onbar -b -l".
Also to restore such a normal level-0 backup, the
logical logs also need to be restored. They are necessary
to synchronize all dbspaces to a consistent point in time.
This is because the normal (level-0) backup does a separate
archive checkpoint for each individual dbspace.
A whole system level-0 backup will also internally backup
the needed logical log records and will have only one
archive checkpoint for all dbspaces. Therefore it can be
restored without the need to restore logical log files.
Note: This will only backup the needed logical log records
and put them into the level-0 whole system backup itself.
It will not do a regular backup of logical log files that would
mark then as backed up (and thus available for cyclical
re-use).
Regards, Martin
--
Martin Fuerderer
IBM Informix Development Munich, Germany
Information Management
IBM Deutschland Research & Development GmbH
Chairman of the Supervisory Board: Martin Jetter
Board of Management: Erich Baier
Corporate Seat: Boeblingen, Germany
Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294
ids-bounces@iiug.org wrote on 10/15/2009 11:21:28 AM:
>
> Yes. A level 0 backup will backup all of the used pages on a space
> regardless
> of any previous backups. I think that you will also find that your
logical
> logs will also be backed up.
>
> If you want to only backup changes since the last level 0 backup,
> then use an
> incremental backup onbar -b -L 1. This will backup all pages changed in
the
> spaces since the last level 0 backup
>
> > To: ids@iiug.org
> > From: informix2009@gmail.com
> > Subject: onbar Level 0 backup question [17583]
> > Date: Thu, 15 Oct 2009 05:12:04 -0400
> >
> > Hi All,
> >
> > as usual i'm using "onbar -b -L 0" to backup my DB.. if i've
> done a level 0
> > backup which means, i'm backing up all devices except logical logs...
My
> > question is, If DBspace1 successfully backed-up and no change
> made, does the
> > "onbar -b -L 0" backup again the DBspace1?.
> >
> >
> >
>
*******************************************************************************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
>
> _________________________________________________________________
> Windows Live: Friends get your Flickr, Yelp, and Digg updates when
> they e-mail
> you.
>
> http://www.microsoft.com/windows/windowslive/see-it-in-action/
> social-network-basics.aspx?ocid=PID23461::T:WLMTAGL:ON:WL:en-
> za:SI_SB_3:092010
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
Yes it does. Level 0 archives are complete archives. They are sufficient
to restore the engine to the state it was in at the beginning of the archive
without any previous archives having been restored.
Art
Art S. Kagel
Oninit (www.oninit.com)
IIUG Board of Directors (art@iiug.org)
Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Oninit, the IIUG, nor any other organization
with which I am associated either explicitly or implicitly. Neither do
those opinions reflect those of other individuals affiliated with any entity
with which I am affiliated nor those of the entities themselves.
On Thu, Oct 15, 2009 at 5:12 AM, JACK PAPA <informix2009@gmail.com> wrote:
> Hi All,
>
> as usual i'm using "onbar -b -L 0" to backup my DB.. if i've done a level 0
> backup which means, i'm backing up all devices except logical logs... My
> question is, If DBspace1 successfully backed-up and no change made, does
> the
> "onbar -b -L 0" backup again the DBspace1?.
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--000e0ce0091e368cb30475f6a046
Thanks for confirmation... Regards,
PLEASE do not post a reply without quoting the posting you are replying to! Art Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Thu, Oct 15, 2009 at 10:11 PM, JACK PAPA <informix2009@gmail.com> wrote: > Thanks for confirmation... > > Regards, > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --001517440f9a54e7b40476046d06
Well explained... Thanks you very much,