Is it ok to use 100% of SQL Server CPU?

I haven't heard of this before but an administrator told me that it is
not good to allow a SQL server to operate at 100% cpu.

This came up when I was running some queries with fairly sizeable
joins. It ran at 100% for about 20 minutes.
I'm not certain of the specific hardware - but it's an 8-way HP server.

I was told that the OS is not able to adequately serve other requests
and that 100% is not good.

Would you happen to know more on this topic? Can you point me to some
MS documentation that addresses this?

I thought 100% was ok since other DB users were still getting good
response.<cjtwantstoknow@.yahoo.com> wrote in message
news:1112649353.788935.142780@.f14g2000cwb.googlegr oups.com...
> I haven't heard of this before but an administrator told me that it is
> not good to allow a SQL server to operate at 100% cpu.
> This came up when I was running some queries with fairly sizeable
> joins. It ran at 100% for about 20 minutes.
> I'm not certain of the specific hardware - but it's an 8-way HP server.
> I was told that the OS is not able to adequately serve other requests
> and that 100% is not good.
> Would you happen to know more on this topic? Can you point me to some
> MS documentation that addresses this?
> I thought 100% was ok since other DB users were still getting good
> response.

"You're both right." :-)

On on hand, you don't want to hit 100% CPU because it does mean that if
additional requests come along, things will get slower.

On the other hand, if no one is complaining, it means you're getting maximum
performance out of your system at this time. That's a good thing.

On the gripping hand, I'd probably look into rewriting the queries or
getting faster hardware. Though I suspect upgrading an 8-way box ain't
gonna be easy. :-)

Is backing up an MDF safe?

Heard a frightening thing: apparently a number of our customers do
backups by just copying the MDF and LDF and backing those up...on a
live database. My hunch is that that could well result in a backup
that's not usable. But I'm told "oh, people have been doing this for
years!"
Is this a sane way to do 'backups' at all? I know that it could be a
reasonable way if a server is shut down and/or the files are detached.
But live?
Any links to information discussing this would be appreciated--if its
dangerous, I'd like to be able to point some of my people to it and
point out the dangers.
Thanks!
> Heard a frightening thing: apparently a number of our customers do
> backups by just copying the MDF and LDF and backing those up...on a
> live database. My hunch is that that could well result in a backup
> that's not usable. But I'm told "oh, people have been doing this for
> years!"
No, that is definitely frightening, and I'd love to see what happens when
you ask them to demonstrate the whole process. (a) you can't copy an MDF
file if it is active, and (b) if the MDF is not detached properly, there is
little chance that you will be able to attach it.
http://www.aspfaq.com/
(Reverse address to reply.)
|||Hi Mike,
One of my basic question is, how are they able to copy .mdf and .ldf files,
when the database is active? It gives sharing violation error, as the files
are used by the database.
Normal practice is to take full backup during off-peak hours if the db is
not huge. And if they want to copy data files and log files, they should
detach the files from sql server instance by applying sp_detach_db. Copy it
to a different folder and then take the file backup.
If they have been doing it for years, I guess they are either taking SQL
server offline or detaching the datafile and logfile, before taking the file
backup.
To confirm, ask them if they are able to restore the database from the
backup they have taken.
Thanks
Yogish
|||"Mike Jones" <barker_djb@.yahoo.com> wrote in message
news:eaObDxO%23EHA.1292@.TK2MSFTNGP10.phx.gbl...
> Heard a frightening thing: apparently a number of our customers do
> backups by just copying the MDF and LDF and backing those up...on a
> live database. My hunch is that that could well result in a backup
> that's not usable. But I'm told "oh, people have been doing this for
> years!"
"And how many practice restores have you done?"

> Is this a sane way to do 'backups' at all? I know that it could be a
> reasonable way if a server is shut down and/or the files are detached.
> But live?
Some backup agents will backup SQL Server "live". If they're using one of
those they're probably ok.
But otherwise I'd worry.

> Any links to information discussing this would be appreciated--if its
> dangerous, I'd like to be able to point some of my people to it and
> point out the dangers.
> Thanks!
|||The problem with detaching a database is that it becomes unavailable. This
is unacceptable in an environment where you want 24x7 availability. The
best option (in my opinion) is to backup to disk using the Transact-SQL
BACKUP command. It is easy to restore a database backed up using this
method via the RESTORE statement. Whatever method people use to backup
their data they should know how to restore/recover the data. It is
important to test the restore process. Test it on a separate server and see
if you can indeed restore the database.
Keith
"Yogish" <yogishkamathg@.icqmail.com> wrote in message
news:C210C859-E155-44F1-83DA-6A62440594B8@.microsoft.com...
> Hi Mike,
> One of my basic question is, how are they able to copy .mdf and .ldf
files,
> when the database is active? It gives sharing violation error, as the
files
> are used by the database.
> Normal practice is to take full backup during off-peak hours if the db is
> not huge. And if they want to copy data files and log files, they should
> detach the files from sql server instance by applying sp_detach_db. Copy
it
> to a different folder and then take the file backup.
> If they have been doing it for years, I guess they are either taking SQL
> server offline or detaching the datafile and logfile, before taking the
file
> backup.
> To confirm, ask them if they are able to restore the database from the
> backup they have taken.
> --
> Thanks
> Yogish

Is backing up an MDF safe?

Heard a frightening thing: apparently a number of our customers do
backups by just copying the MDF and LDF and backing those up...on a
live database. My hunch is that that could well result in a backup
that's not usable. But I'm told "oh, people have been doing this for
years!"
Is this a sane way to do 'backups' at all? I know that it could be a
reasonable way if a server is shut down and/or the files are detached.
But live?
Any links to information discussing this would be appreciated--if its
dangerous, I'd like to be able to point some of my people to it and
point out the dangers.
Thanks!> Heard a frightening thing: apparently a number of our customers do
> backups by just copying the MDF and LDF and backing those up...on a
> live database. My hunch is that that could well result in a backup
> that's not usable. But I'm told "oh, people have been doing this for
> years!"
No, that is definitely frightening, and I'd love to see what happens when
you ask them to demonstrate the whole process. (a) you can't copy an MDF
file if it is active, and (b) if the MDF is not detached properly, there is
little chance that you will be able to attach it.
http://www.aspfaq.com/
(Reverse address to reply.)|||Hi Mike,
One of my basic question is, how are they able to copy .mdf and .ldf files,
when the database is active? It gives sharing violation error, as the files
are used by the database.
Normal practice is to take full backup during off-peak hours if the db is
not huge. And if they want to copy data files and log files, they should
detach the files from sql server instance by applying sp_detach_db. Copy it
to a different folder and then take the file backup.
If they have been doing it for years, I guess they are either taking SQL
server offline or detaching the datafile and logfile, before taking the file
backup.
To confirm, ask them if they are able to restore the database from the
backup they have taken.
Thanks
Yogish|||"Mike Jones" <barker_djb@.yahoo.com> wrote in message
news:eaObDxO%23EHA.1292@.TK2MSFTNGP10.phx.gbl...
> Heard a frightening thing: apparently a number of our customers do
> backups by just copying the MDF and LDF and backing those up...on a
> live database. My hunch is that that could well result in a backup
> that's not usable. But I'm told "oh, people have been doing this for
> years!"
"And how many practice restores have you done?"

> Is this a sane way to do 'backups' at all? I know that it could be a
> reasonable way if a server is shut down and/or the files are detached.
> But live?
Some backup agents will backup SQL Server "live". If they're using one of
those they're probably ok.
But otherwise I'd worry.

> Any links to information discussing this would be appreciated--if its
> dangerous, I'd like to be able to point some of my people to it and
> point out the dangers.
> Thanks!|||The problem with detaching a database is that it becomes unavailable. This
is unacceptable in an environment where you want 24x7 availability. The
best option (in my opinion) is to backup to disk using the Transact-SQL
BACKUP command. It is easy to restore a database backed up using this
method via the RESTORE statement. Whatever method people use to backup
their data they should know how to restore/recover the data. It is
important to test the restore process. Test it on a separate server and see
if you can indeed restore the database.
Keith
"Yogish" <yogishkamathg@.icqmail.com> wrote in message
news:C210C859-E155-44F1-83DA-6A62440594B8@.microsoft.com...
> Hi Mike,
> One of my basic question is, how are they able to copy .mdf and .ldf
files,
> when the database is active? It gives sharing violation error, as the
files
> are used by the database.
> Normal practice is to take full backup during off-peak hours if the db is
> not huge. And if they want to copy data files and log files, they should
> detach the files from sql server instance by applying sp_detach_db. Copy
it
> to a different folder and then take the file backup.
> If they have been doing it for years, I guess they are either taking SQL
> server offline or detaching the datafile and logfile, before taking the
file
> backup.
> To confirm, ask them if they are able to restore the database from the
> backup they have taken.
> --
> Thanks
> Yogish

Is backing up an MDF safe?

Heard a frightening thing: apparently a number of our customers do
backups by just copying the MDF and LDF and backing those up...on a
live database. My hunch is that that could well result in a backup
that's not usable. But I'm told "oh, people have been doing this for
years!"
Is this a sane way to do 'backups' at all? I know that it could be a
reasonable way if a server is shut down and/or the files are detached.
But live?
Any links to information discussing this would be appreciated--if its
dangerous, I'd like to be able to point some of my people to it and
point out the dangers.
Thanks!> Heard a frightening thing: apparently a number of our customers do
> backups by just copying the MDF and LDF and backing those up...on a
> live database. My hunch is that that could well result in a backup
> that's not usable. But I'm told "oh, people have been doing this for
> years!"
No, that is definitely frightening, and I'd love to see what happens when
you ask them to demonstrate the whole process. (a) you can't copy an MDF
file if it is active, and (b) if the MDF is not detached properly, there is
little chance that you will be able to attach it.
--
http://www.aspfaq.com/
(Reverse address to reply.)|||Hi Mike,
One of my basic question is, how are they able to copy .mdf and .ldf files,
when the database is active? It gives sharing violation error, as the files
are used by the database.
Normal practice is to take full backup during off-peak hours if the db is
not huge. And if they want to copy data files and log files, they should
detach the files from sql server instance by applying sp_detach_db. Copy it
to a different folder and then take the file backup.
If they have been doing it for years, I guess they are either taking SQL
server offline or detaching the datafile and logfile, before taking the file
backup.
To confirm, ask them if they are able to restore the database from the
backup they have taken.
--
Thanks
Yogish|||"Mike Jones" <barker_djb@.yahoo.com> wrote in message
news:eaObDxO%23EHA.1292@.TK2MSFTNGP10.phx.gbl...
> Heard a frightening thing: apparently a number of our customers do
> backups by just copying the MDF and LDF and backing those up...on a
> live database. My hunch is that that could well result in a backup
> that's not usable. But I'm told "oh, people have been doing this for
> years!"
"And how many practice restores have you done?"
> Is this a sane way to do 'backups' at all? I know that it could be a
> reasonable way if a server is shut down and/or the files are detached.
> But live?
Some backup agents will backup SQL Server "live". If they're using one of
those they're probably ok.
But otherwise I'd worry.
> Any links to information discussing this would be appreciated--if its
> dangerous, I'd like to be able to point some of my people to it and
> point out the dangers.
> Thanks!|||The problem with detaching a database is that it becomes unavailable. This
is unacceptable in an environment where you want 24x7 availability. The
best option (in my opinion) is to backup to disk using the Transact-SQL
BACKUP command. It is easy to restore a database backed up using this
method via the RESTORE statement. Whatever method people use to backup
their data they should know how to restore/recover the data. It is
important to test the restore process. Test it on a separate server and see
if you can indeed restore the database.
--
Keith
"Yogish" <yogishkamathg@.icqmail.com> wrote in message
news:C210C859-E155-44F1-83DA-6A62440594B8@.microsoft.com...
> Hi Mike,
> One of my basic question is, how are they able to copy .mdf and .ldf
files,
> when the database is active? It gives sharing violation error, as the
files
> are used by the database.
> Normal practice is to take full backup during off-peak hours if the db is
> not huge. And if they want to copy data files and log files, they should
> detach the files from sql server instance by applying sp_detach_db. Copy
it
> to a different folder and then take the file backup.
> If they have been doing it for years, I guess they are either taking SQL
> server offline or detaching the datafile and logfile, before taking the
file
> backup.
> To confirm, ask them if they are able to restore the database from the
> backup they have taken.
> --
> Thanks
> Yogish