Disaster Recovery: Calculate DB size based on .dmp files

Disaster Recovery: Calculate DB size based on .dmp files

Post by przy.. » Tue, 08 Feb 2000 04:00:00



I have a client with no backup of MASTERdb or Help_rev_devices, all I
have is a couple of .dmp's of the production data. In order to run DISK
REINIT I need to know the size of the database, is there any way of
finding out the size of the database device, if all you have to go with
is a backup dump file?

I know it won't be pretty.

`Ken

Sent via Deja.com http://www.deja.com/
Before you buy.

 
 
 

Disaster Recovery: Calculate DB size based on .dmp files

Post by Ira S. Dav » Wed, 09 Feb 2000 04:00:00



>I have a client with no backup of MASTERdb or Help_rev_devices, all I
>have is a couple of .dmp's of the production data. In order to run DISK
>REINIT I need to know the size of the database, is there any way of
>finding out the size of the database device, if all you have to go with
>is a backup dump file?

>I know it won't be pretty.

>`Ken

Since you're talking about disk reinit, I'll assume this is a 6.5
server.  Disk reinit has nothing to do with restoring databases.  It's
used for reattaching existing DEVICES.  When you perform a disk
reinit/refit, the device will be searched for existing databases.  The
system tables sysdatabases, sysdevices, and sysusages will be modified
to reflect any databases found on the device(s).

If you have a dump or backup of the database(s)
Create a small database and attempt to load it from one of the dump
files.  Load database will tell you the minimum size needed to restore
the database.

 
 
 

Disaster Recovery: Calculate DB size based on .dmp files

Post by Brian Proul » Wed, 09 Feb 2000 04:00:00


Ken,

Once you've restored the database as below, I'd suggest building another
empty database that's big enough to hold the data, and then transferring the
contents from the restored database to the empty database.

The reason is that LOAD DATABASE only knows that the database being loaded
into needs to be at least x MB in size. It doesn't know how much of that x
MB was data, and how much was log, and whether the database was expanded at
any point. In other words, it doesn't know the segment mappings of your old
database.

This is bad, because the load database statement basically just does a
page-for-page copy. If the data and log segments aren't set up in the new
database the same way they were set up in the original database, it will
likely copy data pages onto log space, and log pages onto data space. Your
loaded database will work all right, but you might end up filling up your
log with data, or your data with log, and thus getting a lot of 1105 errors,
which can be a serious annoyance.

Transferring the contents of the loaded database into a brand-new database,
using BCP or Database/Object Transfer, starts everything over from scratch.

If you're interested, a better explanation than mine is given in the Books
Online. Look at the topic "Error 2558", in the section "Different Data and
Log Mapping".

Brian




> >I have a client with no backup of MASTERdb or Help_rev_devices, all I
> >have is a couple of .dmp's of the production data. In order to run DISK
> >REINIT I need to know the size of the database, is there any way of
> >finding out the size of the database device, if all you have to go with
> >is a backup dump file?

> >I know it won't be pretty.

> >`Ken

> Since you're talking about disk reinit, I'll assume this is a 6.5
> server.  Disk reinit has nothing to do with restoring databases.  It's
> used for reattaching existing DEVICES.  When you perform a disk
> reinit/refit, the device will be searched for existing databases.  The
> system tables sysdatabases, sysdevices, and sysusages will be modified
> to reflect any databases found on the device(s).

> If you have a dump or backup of the database(s)
> Create a small database and attempt to load it from one of the dump
> files.  Load database will tell you the minimum size needed to restore
> the database.

 
 
 

Disaster Recovery: Calculate DB size based on .dmp files

Post by stock » Tue, 15 Feb 2000 04:00:00


Hi

If you have access to the origional master..sysusages and
master..sysdatanases tables you can work out the device sizes, when they
devices were added to the database etc.

Hope this helps

stocky


> I have a client with no backup of MASTERdb or Help_rev_devices, all I
> have is a couple of .dmp's of the production data. In order to run DISK
> REINIT I need to know the size of the database, is there any way of
> finding out the size of the database device, if all you have to go with
> is a backup dump file?

> I know it won't be pretty.

> `Ken

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

1. Disaster Recovery: Calculate DB size based on .dmp

I have a client with no backup of MASTERdb or
Help_rev_devices, all I have is a couple
of .dmp's of the production data. In order to run
DISK REINIT I need to know the size of the
database, is there any way of finding out the
size of the database device, if all you have to
go with is a backup dump file?

I know it won't be pretty.

`Ken

Sent via Deja.com http://www.deja.com/
Before you buy.

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