Onbar Backup
Jorge asked whether logical log backups are needed if he only takes a nightly level-0 ON-Bar (or ontape) archive and would only ever restore the whole server. Consensus: logs are only required to roll forward past the archive, so if losing transactions since last night is acceptable they can be skipped. Caveats given: a non-whole-system ON-Bar backup uses per-dbspace archive checkpoints and needs logged records to become consistent, so if logs are discarded (LTAPEDEV=/dev/null) use 'onbar -b -w' / 'onbar -r -w'; whole-system backups also trigger a log backup that may be needed for point-in-time (-t/-n) restores. Everyone stressed testing actual restores.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Hi,
If I always do a level 0 backup using onbar, Do I need to backup the logical
logs to do a restore?
Thanks in advance.
Enviado desde mi iPhone
Only if you want to roll forward from the level 0. So logs BEFORE the =
level 0 aren=92t much use, but the ones between your backups are.
j.
On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:
> Hi,=20
>=20
> If I always do a level 0 backup using onbar, Do I need to backup the =
logical=20
> logs to do a restore?=20
>=20
> Thanks in advance.=20
>=20
> Enviado desde mi iPhone=20
>=20
>=20
> =
**************************************************************************=
*****=20
> Forum Note: Use "Reply" to post a response in the discussion forum.=20=
>=20
I have configured only an onbar backup level 0 every night. When I will
need a restore I will do a level 0 restore.
In this case do I need to backup the logical logs or is not necesary?
Thanks in advance.
Enviado desde mi iPhone
El 26/05/2014, a las 14:56, "Jack Parker" <jack.parker4@verizon.net> escribió:
> Only if you want to roll forward from the level 0. So logs BEFORE the =
> level 0 aren=92t much use, but the ones between your backups are.
>
> j.
>
> On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:
>
>> Hi,=20
>> =20
>> If I always do a level 0 backup using onbar, Do I need to backup the =
> logical=20
>> logs to do a restore?=20
>> =20
>> Thanks in advance.=20
>> =20
>> Enviado desde mi iPhone=20
>> =20
>> =20
>> =
> **************************************************************************=
> *****=20
>> Forum Note: Use "Reply" to post a response in the discussion forum.=20=
>
>> =20
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
YES! Here's the deal. If you can afford to lose all transactions that
committed between the archives then you don't need to back up logical logs.
Most sites cannot afford to lose that data.
Art S. Kagel
Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on the IIUG or any other organization with which I sm
associated either explicitely or implicitely not on individuals affiliated
with those organizations.
On May 26, 2014 6:57 PM, "Jorge" <jorgervt@gmail.com> wrote:
> I have configured only an onbar backup level 0 every night. When I will
> need a restore I will do a level 0 restore.
> In this case do I need to backup the logical logs or is not necesary?
>
> Thanks in advance.
>
> Enviado desde mi iPhone
>
> El 26/05/2014, a las 14:56, "Jack Parker" <jack.parker4@verizon.net>
> escribió:
>
> > Only if you want to roll forward from the level 0. So logs BEFORE the =
> > level 0 aren=92t much use, but the ones between your backups are.
> >
> > j.
> >
> > On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:
> >
> >> Hi,=20
> >> =20
> >> If I always do a level 0 backup using onbar, Do I need to backup the =
> > logical=20
> >> logs to do a restore?=20
> >> =20
> >> Thanks in advance.=20
> >> =20
> >> Enviado desde mi iPhone=20
> >> =20
> >> =20
> >> =
> >
> **************************************************************************=
> > *****=20
> >> Forum Note: Use "Reply" to post a response in the discussion forum.=20=
> >
> >> =20
> >
> >
> >
>
>
*******************************************************************************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--14dae947322ba0451904fa55ad68
When you do a restore, it will be to the point of your Level 0 backup. =
Anything that happened after that, is in the logical logs. If you are =
ok restoring to last night instead of 5 minutes before the crash, then =
you don=92t need the logical logs.
j.
On May 26, 2014, at 6:57 PM, Jorge <jorgervt@gmail.com> wrote:
> I have configured only an onbar backup level 0 every night. When I =
will=20
> need a restore I will do a level 0 restore.=20
> In this case do I need to backup the logical logs or is not necesary?=20=
>=20
> Thanks in advance.=20
>=20
> Enviado desde mi iPhone=20
>=20
> El 26/05/2014, a las 14:56, "Jack Parker" <jack.parker4@verizon.net> =
escribi=F3:=20
>=20
>> Only if you want to roll forward from the level 0. So logs BEFORE the =
=3D=20
>> level 0 aren=3D92t much use, but the ones between your backups are.=20=
>>=20
>> j.=20
>>=20
>> On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:=20
>>=20
>>> Hi,=3D20=20
>>> =3D20=20
>>> If I always do a level 0 backup using onbar, Do I need to backup the =
=3D=20
>> logical=3D20=20
>>> logs to do a restore?=3D20=20
>>> =3D20=20
>>> Thanks in advance.=3D20=20
>>> =3D20=20
>>> Enviado desde mi iPhone=3D20=20
>>> =3D20=20
>>> =3D20=20
>>> =3D=20
>> =
**************************************************************************=
=3D=20
>> *****=3D20=20
>>> Forum Note: Use "Reply" to post a response in the discussion =
forum.=3D20=3D=20
>>=20
>>> =3D20=20
>>=20
>>=20
>>=20
> =
**************************************************************************=
*****=20
>> Forum Note: Use "Reply" to post a response in the discussion forum.=20=
>>=20
>=20
>=20
> =
**************************************************************************=
*****=20
> Forum Note: Use "Reply" to post a response in the discussion forum.=20=
>=20
Hi,
whatever in the end you choose to do, please test it thoroughly,
not just by doing some backups, but also by restoring them !
[ I still seem to have in mind (after several years), that ON-Bar
may need logical log content in order to restore certain types
of backups.
This was/is mainly the case when the ON-Bar backup is not a
whole system backup, because in this case, each dbspace
gets backed up with its own, individual archive checkpoint.
A system restored from such a backup is not consistent after
the physical restore part, because of the individual archive
checkpoints of the different dbspaces. In this case, logical log
records are needed, to make the system logically consistent
to a single reference point (i.e. archive checkpoint). The
restore needs to retrieve these logical log records from the
logical log backups. If logical logs were not backed up, then
the restore will not be able to make the system logically
consistent.
The concept of a "whole system backup" was introduced
relatively late for ON-Bar (whereas it always was and is the
only mode for ontape). With a whole system backup, there
is a) only a single archive checkpoint for all dbspaces and
b) the logical log records needed later during restore to
synchronize everything to this single archive checkpoint
are contained within the backup. In this case, no logical
log backup is needed for a restore.
At least, this is what I recall. :)
]
Regards, Martin
--
Martin Fuerderer
IBM Informix Development Munich, Germany
Information Management
Read about the Informix Warehouse Accelerator:
http://tinyurl.com/the-iwa-blog
IBM Deutschland Research & Development GmbH
Chairman of the Supervisory Board: Martina Koederitz
Board of Management: Dirk Wittkopp
Corporate Seat: Boeblingen, Germany
Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294
From: "Art Kagel" <art.kagel@gmail.com>
To: ids@iiug.org,
Date: 05/27/2014 01:10
Subject: Re: Onbar Backup [33104]
Sent by: ids-bounces@iiug.org
YES! Here's the deal. If you can afford to lose all transactions that
committed between the archives then you don't need to back up logical
logs.
Most sites cannot afford to lose that data.
Art S. Kagel
Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on the IIUG or any other organization with which I sm
associated either explicitely or implicitely not on individuals affiliated
with those organizations.
On May 26, 2014 6:57 PM, "Jorge" <jorgervt@gmail.com> wrote:
> I have configured only an onbar backup level 0 every night. When I will
> need a restore I will do a level 0 restore.
> In this case do I need to backup the logical logs or is not necesary?
>
> Thanks in advance.
>
> Enviado desde mi iPhone
>
> El 26/05/2014, a las 14:56, "Jack Parker" <jack.parker4@verizon.net>
> escribió:
>
> > Only if you want to roll forward from the level 0. So logs BEFORE the
=
> > level 0 aren=92t much use, but the ones between your backups are.
> >
> > j.
> >
> > On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:
> >
> >> Hi,=20
> >> =20
> >> If I always do a level 0 backup using onbar, Do I need to backup the
=
> > logical=20
> >> logs to do a restore?=20
> >> =20
> >> Thanks in advance.=20
> >> =20
> >> Enviado desde mi iPhone=20
> >> =20
> >> =20
> >> =
> >
>
**************************************************************************
=
> > *****=20
> >> Forum Note: Use "Reply" to post a response in the discussion
forum.=20=
> >
> >> =20
> >
> >
> >
>
>
*******************************************************************************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--14dae947322ba0451904fa55ad68
*******************************************************************************
Forum Note: Use "Reply" to post a response in the discussion forum.
If you are "throwing away the logical logs" (i.e. LTAPEDEV set to /dev/null)
then you have to use "onbar -b -w" for backups and "onbar -r -w" for restores
- which has performance implications (depending on version).
But as Martin stated "test your restores and not just your backups!" ... in a
test environment :)
In the case of using ontape is the same?
I meant If I only do a level 0 backup using ontape every day, and I only need
a full restore from the last day, I don't need to backup the logical logs?
Thanks in advance.
Enviado desde mi iPhone
El 27/05/2014, a las 02:37, "Martin Fuerderer" <MARTINFU@de.ibm.com> escribió:
> Hi,
>
> whatever in the end you choose to do, please test it thoroughly,
> not just by doing some backups, but also by restoring them !
>
> [ I still seem to have in mind (after several years), that ON-Bar
> may need logical log content in order to restore certain types
> of backups.
>
> This was/is mainly the case when the ON-Bar backup is not a
> whole system backup, because in this case, each dbspace
> gets backed up with its own, individual archive checkpoint.
> A system restored from such a backup is not consistent after
> the physical restore part, because of the individual archive
> checkpoints of the different dbspaces. In this case, logical log
> records are needed, to make the system logically consistent
> to a single reference point (i.e. archive checkpoint). The
> restore needs to retrieve these logical log records from the
> logical log backups. If logical logs were not backed up, then
> the restore will not be able to make the system logically
> consistent.
>
> The concept of a "whole system backup" was introduced
> relatively late for ON-Bar (whereas it always was and is the
> only mode for ontape). With a whole system backup, there
> is a) only a single archive checkpoint for all dbspaces and
> b) the logical log records needed later during restore to
> synchronize everything to this single archive checkpoint
> are contained within the backup. In this case, no logical
> log backup is needed for a restore.
>
> At least, this is what I recall. :)
> ]
>
> Regards, Martin
> --
> Martin Fuerderer
> IBM Informix Development Munich, Germany
> Information Management
>
> Read about the Informix Warehouse Accelerator:
> http://tinyurl.com/the-iwa-blog
>
> IBM Deutschland Research & Development GmbH
> Chairman of the Supervisory Board: Martina Koederitz
> Board of Management: Dirk Wittkopp
> Corporate Seat: Boeblingen, Germany
> Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294
>
> From: "Art Kagel" <art.kagel@gmail.com>
> To: ids@iiug.org,
> Date: 05/27/2014 01:10
> Subject: Re: Onbar Backup [33104]
> Sent by: ids-bounces@iiug.org
>
> YES! Here's the deal. If you can afford to lose all transactions that
> committed between the archives then you don't need to back up logical
> logs.
> Most sites cannot afford to lose that data.
>
> Art S. Kagel
>
> Disclaimer: Please keep in mind that my own opinions are my own opinions
> and do not reflect on the IIUG or any other organization with which I sm
> associated either explicitely or implicitely not on individuals affiliated
>
> with those organizations.
>
> On May 26, 2014 6:57 PM, "Jorge" <jorgervt@gmail.com> wrote:
>
>> I have configured only an onbar backup level 0 every night. When I will
>> need a restore I will do a level 0 restore.
>> In this case do I need to backup the logical logs or is not necesary?
>>
>> Thanks in advance.
>>
>> Enviado desde mi iPhone
>>
>> El 26/05/2014, a las 14:56, "Jack Parker" <jack.parker4@verizon.net>
>> escribió:
>>
>>> Only if you want to roll forward from the level 0. So logs BEFORE the
> =
>>> level 0 aren=92t much use, but the ones between your backups are.
>>>
>>> j.
>>>
>>> On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:
>>>
>>>> Hi,=20
>>>> =20
>>>> If I always do a level 0 backup using onbar, Do I need to backup the
> =
>>> logical=20
>>>> logs to do a restore?=20
>>>> =20
>>>> Thanks in advance.=20
>>>> =20
>>>> Enviado desde mi iPhone=20
>>>> =20
>>>> =20
>>>> =
> **************************************************************************
> =
>
>>> *****=20
>>>> Forum Note: Use "Reply" to post a response in the discussion
> forum.=20=
>>>
>>>> =20
>
>
*******************************************************************************
>
>>> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
*******************************************************************************
>
>> Forum Note: Use "Reply" to post a response in the discussion forum.
>
> --14dae947322ba0451904fa55ad68
>
>
>
*******************************************************************************
>
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
If you only do full server backups and you don't care that you will not be
able to restore to the point of failure, you can ignore the logical logs.
Art
Art S. Kagel, Principal Consultant
ASK Database Management
Blog: http://informix-myview.blogspot.com/
Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on the IIUG, nor any other organization with which I am
associated either explicitly, implicitly, or by inference. 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 Tue, May 27, 2014 at 2:36 PM, Jorge <jorgervt@gmail.com> wrote:
> In the case of using ontape is the same?
> I meant If I only do a level 0 backup using ontape every day, and I only
> need
> a full restore from the last day, I don't need to backup the logical logs?
>
> Thanks in advance.
>
> Enviado desde mi iPhone
>
> El 27/05/2014, a las 02:37, "Martin Fuerderer" <MARTINFU@de.ibm.com>
> escribió:
>
> > Hi,
> >
> > whatever in the end you choose to do, please test it thoroughly,
> > not just by doing some backups, but also by restoring them !
> >
> > [ I still seem to have in mind (after several years), that ON-Bar
> > may need logical log content in order to restore certain types
> > of backups.
> >
> > This was/is mainly the case when the ON-Bar backup is not a
> > whole system backup, because in this case, each dbspace
> > gets backed up with its own, individual archive checkpoint.
> > A system restored from such a backup is not consistent after
> > the physical restore part, because of the individual archive
> > checkpoints of the different dbspaces. In this case, logical log
> > records are needed, to make the system logically consistent
> > to a single reference point (i.e. archive checkpoint). The
> > restore needs to retrieve these logical log records from the
> > logical log backups. If logical logs were not backed up, then
> > the restore will not be able to make the system logically
> > consistent.
> >
> > The concept of a "whole system backup" was introduced
> > relatively late for ON-Bar (whereas it always was and is the
> > only mode for ontape). With a whole system backup, there
> > is a) only a single archive checkpoint for all dbspaces and
> > b) the logical log records needed later during restore to
> > synchronize everything to this single archive checkpoint
> > are contained within the backup. In this case, no logical
> > log backup is needed for a restore.
> >
> > At least, this is what I recall. :)
> > ]
> >
> > Regards, Martin
> > --
> > Martin Fuerderer
> > IBM Informix Development Munich, Germany
> > Information Management
> >
> > Read about the Informix Warehouse Accelerator:
> > http://tinyurl.com/the-iwa-blog
> >
> > IBM Deutschland Research & Development GmbH
> > Chairman of the Supervisory Board: Martina Koederitz
> > Board of Management: Dirk Wittkopp
> > Corporate Seat: Boeblingen, Germany
> > Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294
> >
> > From: "Art Kagel" <art.kagel@gmail.com>
> > To: ids@iiug.org,
> > Date: 05/27/2014 01:10
> > Subject: Re: Onbar Backup [33104]
> > Sent by: ids-bounces@iiug.org
> >
> > YES! Here's the deal. If you can afford to lose all transactions that
> > committed between the archives then you don't need to back up logical
> > logs.
> > Most sites cannot afford to lose that data.
> >
> > Art S. Kagel
> >
> > Disclaimer: Please keep in mind that my own opinions are my own opinions
> > and do not reflect on the IIUG or any other organization with which I sm
> > associated either explicitely or implicitely not on individuals
> affiliated
> >
> > with those organizations.
> >
> > On May 26, 2014 6:57 PM, "Jorge" <jorgervt@gmail.com> wrote:
> >
> >> I have configured only an onbar backup level 0 every night. When I will
> >> need a restore I will do a level 0 restore.
> >> In this case do I need to backup the logical logs or is not necesary?
> >>
> >> Thanks in advance.
> >>
> >> Enviado desde mi iPhone
> >>
> >> El 26/05/2014, a las 14:56, "Jack Parker" <jack.parker4@verizon.net>
> >> escribió:
> >>
> >>> Only if you want to roll forward from the level 0. So logs BEFORE the
> > =
> >>> level 0 aren=92t much use, but the ones between your backups are.
> >>>
> >>> j.
> >>>
> >>> On May 26, 2014, at 5:48 PM, Jorge <jorgervt@gmail.com> wrote:
> >>>
> >>>> Hi,=20
> >>>> =20
> >>>> If I always do a level 0 backup using onbar, Do I need to backup the
> > =
> >>> logical=20
> >>>> logs to do a restore?=20
> >>>> =20
> >>>> Thanks in advance.=20
> >>>> =20
> >>>> Enviado desde mi iPhone=20
> >>>> =20
> >>>> =20
> >>>> =
> >
> **************************************************************************
> > =
> >
> >>> *****=20
> >>>> Forum Note: Use "Reply" to post a response in the discussion
> > forum.=20=
> >>>
> >>>> =20
> >
> >
>
>
*******************************************************************************
> >
> >>> Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> >
>
>
*******************************************************************************
> >
> >> Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> > --14dae947322ba0451904fa55ad68
> >
> >
> >
>
>
*******************************************************************************
> >
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> >
> >
>
>
*******************************************************************************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--047d7b3a8aa851516804fa6616b5
I did find that with onbar -w whole system backups that the whole system backup
also kicks off a onbar -b -l to backup logs.
That log backup CAN be required to get back to a consistenct point in time for
the server (even with all user databases being unlogged).
Of course with onbar you cannot specify which full backup (or incremental
backup) to restore to.
You have to tell the onbar which point in time to restore to with -t option
which is only down the second (or -n option which is down the logical log) so
that log records from the additional log backup may be required.
Regards,
David.
> On 27 May 2014 at 11:51 JON RITSON <jonritson@sky.com> wrote:
>
>
> If you are "throwing away the logical logs" (i.e. LTAPEDEV set to /dev/null)
> then you have to use "onbar -b -w" for backups and "onbar -r -w" for restores
> - which has performance implications (depending on version).
>
> But as Martin stated "test your restores and not just your backups!" ... in a
> test environment :)
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>