consistency check on offline database
Andreas asked whether an IDS database can be consistency-checked (oncheck-style, at table/page level) on an offline split-mirror (SRDF/BCV) copy without starting an instance on it, since starting IDS would write a checkpoint and destroy the copy's usability for an external restore with log rollforward. The discussion turned mostly to backup/restore strategy: using onmode -c block, raw-device tape copies and onbar -r -e, and a suggestion to keep a second BCV (e.g. at the hot site) and bring that up as a separate instance to run onchecks there. No tool for checking a truly offline copy was identified; no resolution is recorded.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Hello,
is there a possibility/tools to do a consistency check on an offline database?
Background information:
We do full backups with onmode -c block and a split disk mirror solution
(SRDF, BCV).
We would like to check the consistency (at table or page level) of the mirror
copy, but without starting an IDS instance on the mirror copy, because that
would change the copy (e.g. write a checkpoint) and we would loose the
possibility to apply logical logs to
the mirror copy in case of a restore.
Regards,
Andreas Kutsche
-------------------------------------------
SPAR Oesterreichische Warenhandels-AG
Hauptzentrale
Europastrasse 3
A - 5015 Salzburg
Tel: +43 662 4470 24223
Mobile: +43 664 6259575
E-Mail: Andreas.KUTSCHE@spar.at
Internet: http://www.spar.at
Wichtiger Hinweis: Der Inhalt dieser E-Mail kann vertrauliche und rechtlich
geschützte Informationen, insbesondere Betriebs- oder Geschäftsgeheimnisse,
enthalten, zu deren Geheimhaltung der Empfänger verpflichtet ist. Die
Informationen in dieser E-Mail sind ausschließlich für den Adressaten
bestimmt. Sollten Sie die E-Mail irrtümlich erhalten haben so ersuchen wir
Sie, die Nachricht von Ihrem System zu löschen und sich mit uns in Verbindung
zu setzen.
Über das Internet versandte E-Mails können leicht manipuliert oder unter
fremdem Namen erstellt werden. Daher schließen wir die rechtliche
Verbindlichkeit der in dieser Nachricht enthaltenen Informationen aus. Der
Inhalt der E-Mail ist nur rechtsverbindlich, wenn er von uns schriftlich
bestätigt und gezeichnet wird.
Sollte trotz der von uns verwendeten Virus-Schutzprogramme durch die Zusendung
von E-Mails ein Virus in Ihre Systeme gelangen, haften wir nicht für evtl.
hieraus entstehende Schäden.
Wir danken für Ihr Verständnis.
Important notice: The contents of this e-mail may contain confidential and
legally protected information that is in particular related to operational and
trade secrets, which the recipient is obliged to treat as confidential. The
information in this e-mail is made available exclusively for use by the
addressee. In the event that the e-mail may have been sent to you in error, we
would ask you to kindly delete this communication from your system and to
contact us.
E-mails sent via the Internet can be easily manipulated or sent out under
someone else's name. We therefore do not accept legal liability for the
information contained in this communication. The contents of the e-mail are
only legally binding if they have been confirmed and signed by us in writing.
If, in spite of our using Antivirus protection software, a virus may have
penetrated your system through the sending of this e-mail, we do not accept
liability for any damage that may possibly arise as a result of this.
We trust that you appreciate our position.
-------------------------------------------
On 04/01/07, Andreas.KUTSCHE@spar.at <andreas.kutsche@spar.at> wrote:
>
> Hello,
>
> is there a possibility/tools to do a consistency check on an offline
database?
>
> Background information:
> We do full backups with onmode -c block and a split disk mirror solution
> (SRDF, BCV).
> We would like to check the consistency (at table or page level) of the mirror
> copy, but without starting an IDS instance on the mirror copy, because that
> would change the copy (e.g. write a checkpoint) and we would loose the
> possibility to apply logical logs to
> the mirror copy in case of a restore.
>
> Regards,
> Andreas Kutsche
> -------------------------------------------
> SPAR Oesterreichische Warenhandels-AG
> Hauptzentrale
> Europastrasse 3
> A - 5015 Salzburg
>
> Tel: +43 662 4470 24223
> Mobile: +43 664 6259575
> E-Mail: Andreas.KUTSCHE@spar.at
> Internet: http://www.spar.at
<SNIP>
Andreas
I don't have anything to offer on your question, however I am at a bit
of a loss understanding your backup/restore strategy? You are taking a
'point in time' backup of the disk by splitting mirrors, I assume you
then back this up to tape in some way, how would yu then restore this?
How are you backing up logs and how do you anticipate applying these
to a restored database? have you tested this?
Keith
>
> Andreas
>
> I don't have anything to offer on your question, however I am
> at a bit
> of a loss understanding your backup/restore strategy? You are
> taking a
> 'point in time' backup of the disk by splitting mirrors, I assume you
> then back this up to tape in some way, how would yu then
> restore this?
> How are you backing up logs and how do you anticipate applying these
> to a restored database? have you tested this?
>
> Keith
>
The 'point in time' backup (blocked IDS after checkpoint) can be resynched
from the mirror disks to the primary disks (if the last backup is needed).
As you mentioned we save the raw disk devices of the copy to tape and these
tapes can be restored back to the disks (primary or mirror disks).
Logical log backup is with onbar/ism and for a restore with rollforward
you have to use the external restore option of onbar (after resynching disks):
onbar -r -eor
onbar -r -e -p
onbar -r -l
Regards,
Andreas Kutsche
-------------------------------------------
SPAR Oesterreichische Warenhandels-AG
Hauptzentrale
Europastrasse 3
A - 5015 Salzburg
Tel: +43 662 4470 24223
Mobile: +43 664 6259575
E-Mail: Andreas.KUTSCHE@spar.at
Internet: http://www.spar.at
Wichtiger Hinweis: Der Inhalt dieser E-Mail kann vertrauliche und rechtlich
geschützte Informationen, insbesondere Betriebs- oder Geschäftsgeheimnisse,
enthalten, zu deren Geheimhaltung der Empfänger verpflichtet ist. Die
Informationen in dieser E-Mail sind ausschließlich für den Adressaten
bestimmt. Sollten Sie die E-Mail irrtümlich erhalten haben so ersuchen wir
Sie, die Nachricht von Ihrem System zu löschen und sich mit uns in Verbindung
zu setzen.
Über das Internet versandte E-Mails können leicht manipuliert oder unter
fremdem Namen erstellt werden. Daher schließen wir die rechtliche
Verbindlichkeit der in dieser Nachricht enthaltenen Informationen aus. Der
Inhalt der E-Mail ist nur rechtsverbindlich, wenn er von uns schriftlich
bestätigt und gezeichnet wird.
Sollte trotz der von uns verwendeten Virus-Schutzprogramme durch die Zusendung
von E-Mails ein Virus in Ihre Systeme gelangen, haften wir nicht für evtl.
hieraus entstehende Schäden.
Wir danken für Ihr Verständnis.
Important notice: The contents of this e-mail may contain confidential and
legally protected information that is in particular related to operational and
trade secrets, which the recipient is obliged to treat as confidential. The
information in this e-mail is made available exclusively for use by the
addressee. In the event that the e-mail may have been sent to you in error, we
would ask you to kindly delete this communication from your system and to
contact us.
E-mails sent via the Internet can be easily manipulated or sent out under
someone else's name. We therefore do not accept legal liability for the
information contained in this communication. The contents of the e-mail are
only legally binding if they have been confirmed and signed by us in writing.
If, in spite of our using Antivirus protection software, a virus may have
penetrated your system through the sending of this e-mail, we do not accept
liability for any damage that may possibly arise as a result of this.
We trust that you appreciate our position.
-------------------------------------------
That is an interesting question.
I don't have the answer. Is there more about your env that you can share?
We also do SRDF and play with BCVs, but we don't back up the raw data to tape
because that's a lot more to back up than if informix/onbar controlled it and
only sent what is used to the backup media.
Do you have a test systems that can take the BCV image? then bring up the test
system and run onchecks?
i.e., we copy PRD BCVs to several test systems and bring those up as informix
instances for those test systems.
We also have SRDF running to the R2s at our hotsite. The hotsite has a BCV
which normally is in sync with the R2s. When we need to test hotsite, we split
the BCV and bring informix up on it, meanwhile SRDF is still in sync with
production DB.
We run full onchecks at the hotsite.
Norma Jean Sebastian
ERP Support Administration
IT - Enterprise Technical Services
-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
Andreas.KUTSCHE@spar.at
Sent: Thursday, January 04, 2007 6:28 AM
To: ids@iiug.org
Subject: consistency check on offline database [8105]
Hello,
is there a possibility/tools to do a consistency check on an offline database?
Background information:
We do full backups with onmode -c block and a split disk mirror solution
(SRDF, BCV).
We would like to check the consistency (at table or page level) of the mirror
copy, but without starting an IDS instance on the mirror copy, because that
would change the copy (e.g. write a checkpoint) and we would loose the
possibility to apply logical logs to
the mirror copy in case of a restore.
Regards,
Andreas Kutsche
-------------------------------------------
SPAR Oesterreichische Warenhandels-AG
Hauptzentrale
Europastrasse 3
A - 5015 Salzburg
Tel: +43 662 4470 24223
Mobile: +43 664 6259575
E-Mail: Andreas.KUTSCHE@spar.at
Internet: http://www.spar.at
Wichtiger Hinweis: Der Inhalt dieser E-Mail kann vertrauliche und rechtlich
geschützte Informationen, insbesondere Betriebs- oder Geschäftsgeheimnisse,
enthalten, zu deren Geheimhaltung der Empfänger verpflichtet ist. Die
Informationen in dieser E-Mail sind ausschließlich für den Adressaten
bestimmt. Sollten Sie die E-Mail irrtümlich erhalten haben so ersuchen wir
Sie, die Nachricht von Ihrem System zu löschen und sich mit uns in Verbindung
zu setzen.
Über das Internet versandte E-Mails können leicht manipuliert oder unter
fremdem Namen erstellt werden. Daher schließen wir die rechtliche
Verbindlichkeit der in dieser Nachricht enthaltenen Informationen aus. Der
Inhalt der E-Mail ist nur rechtsverbindlich, wenn er von uns schriftlich
bestätigt und gezeichnet wird.
Sollte trotz der von uns verwendeten Virus-Schutzprogramme durch die Zusendung
von E-Mails ein Virus in Ihre Systeme gelangen, haften wir nicht für evtl.
hieraus entstehende Schäden.
Wir danken für Ihr Verständnis.
Important notice: The contents of this e-mail may contain confidential and
legally protected information that is in particular related to operational and
trade secrets, which the recipient is obliged to treat as confidential. The
information in this e-mail is made available exclusively for use by the
addressee. In the event that the e-mail may have been sent to you in error, we
would ask you to kindly delete this communication from your system and to
contact us.
E-mails sent via the Internet can be easily manipulated or sent out under
someone else's name. We therefore do not accept legal liability for the
information contained in this communication. The contents of the e-mail are
only legally binding if they have been confirmed and signed by us in writing.
If, in spite of our using Antivirus protection software, a virus may have
penetrated your system through the sending of this e-mail, we do not accept
liability for any damage that may possibly arise as a result of this.
We trust that you appreciate our position.
-------------------------------------------
*******************************************************************************
Forum Note: Use "Reply" to post a response in the discussion forum.
============================================================
The information contained in this message may be privileged
and confidential and protected from disclosure. If the reader
of this message is not the intended recipient, or an employee
or agent responsible for delivering this message to the
intended recipient, you are hereby notified that any reproduction,
dissemination or distribution of this communication is strictly
prohibited. If you have received this communication in error,
please notify us immediately by replying to the message and
deleting it from your computer. Thank you. Tellabs
============================================================
Hello,
we have two big production systems with about 5 TB each (running on HPUX
IA64/Montecito and HP Surestore/XPsomethings), therefore the number of copies
is quite small.
We have one test system built from a Continous Access (SRDF) copy at a
failover site, but that system is rebuilt only every few months, because it is
used for implementation and development projects.
There's a BCV on the main site (maybe it would be better to locate it on the
failover site?)
which is synchronized once every day. That would be our candidate for
consistency checks.
Do you have a BCV of the production system on both sites (main site and hot
site)? Then you can run an IDS instance on one of them without compromising
your ability to do a quick restore, but we have only one BCV.
If the system runs on new disks (or the disks are initialied with zeroes)
unused space in the database doesn't use much space on the tape because it
gets compressed automatically.
Okay, that's correct only at the beginning and will get worse over time.
Do you run your onbar backups on the production system? Doesn't that hurt your
performance?
Do you run a full backup every day?
Regards,
Andreas Kutsche
-------------------------------------------
SPAR Oesterreichische Warenhandels-AG
Hauptzentrale
Europastrasse 3
A - 5015 Salzburg
Tel: +43 662 4470 24223
Mobile: +43 664 6259575
E-Mail: Andreas.KUTSCHE@spar.at
Internet: http://www.spar.at
Wichtiger Hinweis: Der Inhalt dieser E-Mail kann vertrauliche und rechtlich
geschützte Informationen, insbesondere Betriebs- oder Geschäftsgeheimnisse,
enthalten, zu deren Geheimhaltung der Empfänger verpflichtet ist. Die
Informationen in dieser E-Mail sind ausschließlich für den Adressaten
bestimmt. Sollten Sie die E-Mail irrtümlich erhalten haben so ersuchen wir
Sie, die Nachricht von Ihrem System zu löschen und sich mit uns in Verbindung
zu setzen.
Über das Internet versandte E-Mails können leicht manipuliert oder unter
fremdem Namen erstellt werden. Daher schließen wir die rechtliche
Verbindlichkeit der in dieser Nachricht enthaltenen Informationen aus. Der
Inhalt der E-Mail ist nur rechtsverbindlich, wenn er von uns schriftlich
bestätigt und gezeichnet wird.
Sollte trotz der von uns verwendeten Virus-Schutzprogramme durch die Zusendung
von E-Mails ein Virus in Ihre Systeme gelangen, haften wir nicht für evtl.
hieraus entstehende Schäden.
Wir danken für Ihr Verständnis.
Important notice: The contents of this e-mail may contain confidential and
legally protected information that is in particular related to operational and
trade secrets, which the recipient is obliged to treat as confidential. The
information in this e-mail is made available exclusively for use by the
addressee. In the event that the e-mail may have been sent to you in error, we
would ask you to kindly delete this communication from your system and to
contact us.
E-mails sent via the Internet can be easily manipulated or sent out under
someone else's name. We therefore do not accept legal liability for the
information contained in this communication. The contents of the e-mail are
only legally binding if they have been confirmed and signed by us in writing.
If, in spite of our using Antivirus protection software, a virus may have
penetrated your system through the sending of this e-mail, we do not accept
liability for any damage that may possibly arise as a result of this.
We trust that you appreciate our position.
-------------------------------------------
Hi Andreas,
What's your version of IDS?
I believe (others will need to respond/verify) that newer versions of
oncheck will not lock tables?.... (sure would be nice if that is
true). therefore, you could run it slowly in production without harm.
Andreas, settle in for a long read.... (sorry)....
I think our setup is much broader than yours although your DB is much
bigger. This makes it easier for me to run onchecks on 'near
production' data. And in a pinch, I can get agreement to run limited
onchecks on production. (i.e. find an issue on one table on a test
system or hotsite, and then that's the only table I need to hit in
production instead of doing them all).
We have an EMC BCV on our production database, and one at our hotsite.
We have EMC SRDF running from the R1s (the production database disks) to
the R2s (hotsite). Because the hotsite has its own BCV, when we want
the hotsite up for testing or projects, we sync the hotsite BCV to the
hotsite R2, then split the hotsite BCV and bring it up as the hotsite
database. This gives us a working system at the hotsite AND we are
still keeping the SRDF from production R1 disks to the hotsite R2 disks.
>> There's a BCV on the main site (maybe it would be better to locate it
on the
>> failover site?) which is synchronized once every day. That would be
our candidate for
>> consistency checks.
it is something you could think about. We have them on both ends (PRD
and hotsite) so not an issue for me.
Yes, as you said, my multiple BCVs and systems enable me to do onchecks
on near-production data images without compromising my ability to do a
PRD BCV split and have that quick restore image ready.
>> If the system runs on new disks (or the disks are initialied with
zeroes)
>> unused space in the database doesn't use much space on the tape
because it
>> gets compressed automatically.
Hmmmm.... we didn't think of that, and I guess our Symantec/Veritas
Netbackup setup is pretty solid so we didn't put too much thought into
raw backups from BCV. Although, that is my goal on our Oracle system so
thanks for that info.
>>Do you run your onbar backups on the production system?
Yes. We are IDS 9.4 on Sun Solaris (64 bit all around). We use
Symantec/Veritas Netbackup as the partner for onbar. My onconfig is set
to run 12 backup threads, I have 128 dbspaces to backup with those 12
threads. Our backup runs from 4AM to approx 8AM daily. We redesigned
our Netbackup setup and this important backup goes to disk not tape.....
it used to take 8 hours for the backup, but going to disk, we're down to
4 hours.
Restores of the onbar backups take about 6 or more hours. So yes, the
BCV is a much quicker fall-back, but 6 hours isn't so bad either.
It all depends where you want / can afford to invest in your
infrastructure.
>>Do you run a full backup every day?
Yes. Level 0 every day. The pressure to change to a different strategy
with level 1s and 2s has never been strong for us, so level 0 ever since
I remember (year 2000).
>>Doesn't that hurt your performance?
Yes, it impacts. But here's another reason we're probably different.
We have SAP. We have a central database instance, a central SAP
instance, and multiple application servers. The central DB instance and
the central SAP instance are on the same Solaris box at this time. The
users and batch jobs running through SAP are load balanced via SAP
amongst the SAP central instance and application servers (this includes
2 SAP batch servers). Because the SAP processing between the hours of
4-8AM is light on our system, it is ok to pummel the central DB
instance/Solaris server with the IDS onbar backup. Matter of fact,
monitoring it with a vmstat.... the CPUs on this DB server have 0% idle
CPU during the backup.
Meanwhile, the SAP central instance memory holds a lot of data, and
shares that out with the SAP memory on the application and batch
servers. Our batch processing is pretty much finished by 4AM, and our
users have not yet started with heavy usage.
Acutally what could hurt our performance more is the SRDF. When SRDF is
running, I have double-digit checkpoints on the database. However with
a pile of SAP application memory/cache (6gb I think) and a pile of
informix memory/cache (currently at 8gb), and a pile of EMC disk
cache..... we're cache rich.... and the users don't notice the
double-digit checkpoints. (long checkpoints are bad only if the users
feel the pain).
Hope this info is helpful.
If you have read this far and still would like more.... you could mail
me directly at normajean.sebastian@tellabs.xxx (replace xxx with com)
Norma Jean Sebastian
ERP Support Administration
IT - Enterprise Technical Services
-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
Andreas.KUTSCHE@spar.at
Sent: Thursday, January 04, 2007 1:03 PM
To: ids@iiug.org
Subject: AW: consistency check on offline database [8116]
Hello,
we have two big production systems with about 5 TB each (running on HPUX
IA64/Montecito and HP Surestore/XPsomethings), therefore the number of
copies
is quite small.
We have one test system built from a Continous Access (SRDF) copy at a
......
============================================================
The information contained in this message may be privileged
and confidential and protected from disclosure. If the reader
of this message is not the intended recipient, or an employee
or agent responsible for delivering this message to the
intended recipient, you are hereby notified that any reproduction,
dissemination or distribution of this communication is strictly
prohibited. If you have received this communication in error,
please notify us immediately by replying to the message and
deleting it from your computer. Thank you. Tellabs
============================================================