Could making an extra backup cause data loss?

I'm wondering whether in some circumstances, making an additional SQL backup
could cause data loss.
For ezample, a database is configured with the full recovery model. The DBA,
Alice, has scheduled daily full backups at 0200, and transaction log backups
at 0000, 0600, 1200 and 1800.
Suppose programmer Bob makes an additional full backup at 1000 so that he
can copy the database to his laptop, then removes this backup from the
server and doesn't tell Alice.
What happens if Alice wants to do a restore at 1201? Can she just restore
the 0200 full backup followed by the 0600 and 1200 transaction log backups,
or will there be missing data between 0600 and 1000?
Any comments appreciated. Thanks,
Simon
Hi
A full back does not affect the transaction log sequence as long as you do
not set it to truncate the log also (option when you do it through
Enterprise Manager).
In your case, the full backup contains all the data and the log from 0600,
but does not truncate the log. The 1200 log dump contains the log from 0600
to 1200.
Regards
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"Simon" <simon@.antispam.aardvarks> wrote in message
news:419524d5$0$226$bed64819@.news.gradwell.net...
> I'm wondering whether in some circumstances, making an additional SQL
backup
> could cause data loss.
> For ezample, a database is configured with the full recovery model. The
DBA,
> Alice, has scheduled daily full backups at 0200, and transaction log
backups
> at 0000, 0600, 1200 and 1800.
> Suppose programmer Bob makes an additional full backup at 1000 so that he
> can copy the database to his laptop, then removes this backup from the
> server and doesn't tell Alice.
> What happens if Alice wants to do a restore at 1201? Can she just restore
> the 0200 full backup followed by the 0600 and 1200 transaction log
backups,
> or will there be missing data between 0600 and 1000?
> Any comments appreciated. Thanks,
> Simon
>
|||As mike says - the good thing about log backups is that they are not affected
by full backups - if you have the sequence of logs you can restore from any
full backup.
It's important that Bob doesn't do a log backup though as this will cause
problems - even if he uses the NO_TRUNCATE option.
"Simon" wrote:

> I'm wondering whether in some circumstances, making an additional SQL backup
> could cause data loss.
> For ezample, a database is configured with the full recovery model. The DBA,
> Alice, has scheduled daily full backups at 0200, and transaction log backups
> at 0000, 0600, 1200 and 1800.
> Suppose programmer Bob makes an additional full backup at 1000 so that he
> can copy the database to his laptop, then removes this backup from the
> server and doesn't tell Alice.
> What happens if Alice wants to do a restore at 1201? Can she just restore
> the 0200 full backup followed by the 0600 and 1200 transaction log backups,
> or will there be missing data between 0600 and 1000?
> Any comments appreciated. Thanks,
> Simon
>
>

Could making an extra backup cause data loss?

I'm wondering whether in some circumstances, making an additional SQL backup
could cause data loss.
For ezample, a database is configured with the full recovery model. The DBA,
Alice, has scheduled daily full backups at 0200, and transaction log backups
at 0000, 0600, 1200 and 1800.
Suppose programmer Bob makes an additional full backup at 1000 so that he
can copy the database to his laptop, then removes this backup from the
server and doesn't tell Alice.
What happens if Alice wants to do a restore at 1201? Can she just restore
the 0200 full backup followed by the 0600 and 1200 transaction log backups,
or will there be missing data between 0600 and 1000?
Any comments appreciated. Thanks,
SimonHi
A full back does not affect the transaction log sequence as long as you do
not set it to truncate the log also (option when you do it through
Enterprise Manager).
In your case, the full backup contains all the data and the log from 0600,
but does not truncate the log. The 1200 log dump contains the log from 0600
to 1200.
Regards
--
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"Simon" <simon@.antispam.aardvarks> wrote in message
news:419524d5$0$226$bed64819@.news.gradwell.net...
> I'm wondering whether in some circumstances, making an additional SQL
backup
> could cause data loss.
> For ezample, a database is configured with the full recovery model. The
DBA,
> Alice, has scheduled daily full backups at 0200, and transaction log
backups
> at 0000, 0600, 1200 and 1800.
> Suppose programmer Bob makes an additional full backup at 1000 so that he
> can copy the database to his laptop, then removes this backup from the
> server and doesn't tell Alice.
> What happens if Alice wants to do a restore at 1201? Can she just restore
> the 0200 full backup followed by the 0600 and 1200 transaction log
backups,
> or will there be missing data between 0600 and 1000?
> Any comments appreciated. Thanks,
> Simon
>|||As mike says - the good thing about log backups is that they are not affected
by full backups - if you have the sequence of logs you can restore from any
full backup.
It's important that Bob doesn't do a log backup though as this will cause
problems - even if he uses the NO_TRUNCATE option.
"Simon" wrote:
> I'm wondering whether in some circumstances, making an additional SQL backup
> could cause data loss.
> For ezample, a database is configured with the full recovery model. The DBA,
> Alice, has scheduled daily full backups at 0200, and transaction log backups
> at 0000, 0600, 1200 and 1800.
> Suppose programmer Bob makes an additional full backup at 1000 so that he
> can copy the database to his laptop, then removes this backup from the
> server and doesn't tell Alice.
> What happens if Alice wants to do a restore at 1201? Can she just restore
> the 0200 full backup followed by the 0600 and 1200 transaction log backups,
> or will there be missing data between 0600 and 1000?
> Any comments appreciated. Thanks,
> Simon
>
>

Could making an extra backup cause data loss?

I'm wondering whether in some circumstances, making an additional SQL backup
could cause data loss.
For ezample, a database is configured with the full recovery model. The DBA,
Alice, has scheduled daily full backups at 0200, and transaction log backups
at 0000, 0600, 1200 and 1800.
Suppose programmer Bob makes an additional full backup at 1000 so that he
can copy the database to his laptop, then removes this backup from the
server and doesn't tell Alice.
What happens if Alice wants to do a restore at 1201? Can she just restore
the 0200 full backup followed by the 0600 and 1200 transaction log backups,
or will there be missing data between 0600 and 1000?
Any comments appreciated. Thanks,
SimonHi
A full back does not affect the transaction log sequence as long as you do
not set it to truncate the log also (option when you do it through
Enterprise Manager).
In your case, the full backup contains all the data and the log from 0600,
but does not truncate the log. The 1200 log dump contains the log from 0600
to 1200.
Regards
--
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
IM: mike@.epprecht.net
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"Simon" <simon@.antispam.aardvarks> wrote in message
news:419524d5$0$226$bed64819@.news.gradwell.net...
> I'm wondering whether in some circumstances, making an additional SQL
backup
> could cause data loss.
> For ezample, a database is configured with the full recovery model. The
DBA,
> Alice, has scheduled daily full backups at 0200, and transaction log
backups
> at 0000, 0600, 1200 and 1800.
> Suppose programmer Bob makes an additional full backup at 1000 so that he
> can copy the database to his laptop, then removes this backup from the
> server and doesn't tell Alice.
> What happens if Alice wants to do a restore at 1201? Can she just restore
> the 0200 full backup followed by the 0600 and 1200 transaction log
backups,
> or will there be missing data between 0600 and 1000?
> Any comments appreciated. Thanks,
> Simon
>|||As mike says - the good thing about log backups is that they are not affecte
d
by full backups - if you have the sequence of logs you can restore from any
full backup.
It's important that Bob doesn't do a log backup though as this will cause
problems - even if he uses the NO_TRUNCATE option.
"Simon" wrote:

> I'm wondering whether in some circumstances, making an additional SQL back
up
> could cause data loss.
> For ezample, a database is configured with the full recovery model. The DB
A,
> Alice, has scheduled daily full backups at 0200, and transaction log backu
ps
> at 0000, 0600, 1200 and 1800.
> Suppose programmer Bob makes an additional full backup at 1000 so that he
> can copy the database to his laptop, then removes this backup from the
> server and doesn't tell Alice.
> What happens if Alice wants to do a restore at 1201? Can she just restore
> the 0200 full backup followed by the 0600 and 1200 transaction log backups
,
> or will there be missing data between 0600 and 1000?
> Any comments appreciated. Thanks,
> Simon
>
>

Corrupted MSDE files encountered

This is just to pass on something that caused me a lot of problems until we
(I used a support call) discovered the root cause. I hope someone finds it
helpful.
I ran into a frustrating problem when installing MSDE as a part of two
different application -- Backup Exec and WSUS. I also ran into it when I
downloaded MSDE200A and tried to install it seperately.
Setup would start, load and start to run an msi file, then report it
couldn't find that msi. This happened the same way in the Backup Exec
install, the WSUS install and the MSDE200A install.
After a fresh download the install ran fine. I thought about this, then
realized, and subsequently proved to my satisfaction, the problem only
happened when I downloaded a self-expanding exe file and used Winzip to
expand it to my setup source directories.
When I do this, MSDE setup fails when running a .msi file. If I just
double-click the exe and let it expand itself to a temp directory, the MSDE
setup runs fine. I did this with all three failed setups.
I was using Winzip 8. I don't know if it happens with other versions or not.
I don't know if the problem lies in Winzip or in the compression of MSDE
files and don't have the resouces to find out. I am copying this to WINZIP
and to the MS MSDE forum..
Axel Larson,
Share What You Know,
Learn What You Don't
Thanks for sharing this.
Frank McCallister SBS MVP
COMPUMAC
"Axel" <Axel@.office.Reliasense.com> wrote in message
news:%239mpCW2fFHA.3940@.TK2MSFTNGP14.phx.gbl...
> This is just to pass on something that caused me a lot of problems until
> we
> (I used a support call) discovered the root cause. I hope someone finds it
> helpful.
> I ran into a frustrating problem when installing MSDE as a part of two
> different application -- Backup Exec and WSUS. I also ran into it when I
> downloaded MSDE200A and tried to install it seperately.
> Setup would start, load and start to run an msi file, then report it
> couldn't find that msi. This happened the same way in the Backup Exec
> install, the WSUS install and the MSDE200A install.
> After a fresh download the install ran fine. I thought about this, then
> realized, and subsequently proved to my satisfaction, the problem only
> happened when I downloaded a self-expanding exe file and used Winzip to
> expand it to my setup source directories.
> When I do this, MSDE setup fails when running a .msi file. If I just
> double-click the exe and let it expand itself to a temp directory, the
> MSDE
> setup runs fine. I did this with all three failed setups.
> I was using Winzip 8. I don't know if it happens with other versions or
> not.
> I don't know if the problem lies in Winzip or in the compression of MSDE
> files and don't have the resouces to find out. I am copying this to WINZIP
> and to the MS MSDE forum..
> --
> Axel Larson,
> Share What You Know,
> Learn What You Don't
>