Thursday, March 29, 2012

Data files location.

Hello.
I have large database with very high workload (100 trans/sec avg.)
When database files were located on local disks on the server I tried to
part data files, index files, files with binary objects and log files from
each other and place them on separate physical discs to improve performance.
Now we're planning to use cluster server with external storage (HP MSA 1000).
A technician, who was configuring the hardware, told me that in this
configuration storage library segments presented to MSSQL server as discs are
already spread on many physical discs and there is no reason now to put
database files on different drives.
The question is: is this true? Will it be good if I'll put all files on
one logical disc and let storage library to manage data distridution across
physical discs?
Thanks.
Serge Shakhov
Hi
Ideally, the log and data portion of the database should be on different
LUNs ("storage library segments") and the Log should be on RAID-1 or RAID-10.
RAID-5 is not optimal for the Log due to it's high latency. Actually, with
the price of storage today, RAID-5 has no place near a IO intensive server.
Further to that, if you get presented 5 LUNs, and then present them to SQL
Server as only one disk, generally, you do not use up all the storage, so the
first 2 or 3 of the LUNS will have all the traffic, and there is no data on
the other LUNs, so they get no traffic. You don't want this. You rather have
5 database files, one on each LUN so that all the drives are busy.
Without knowing exactly how the LUNs are mapped to the physical drives and
how you want to map to LUNs to OS drives, I can't pass more comment.
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"Serge Shakhov" wrote:

> Hello.
> I have large database with very high workload (100 trans/sec avg.)
> When database files were located on local disks on the server I tried to
> part data files, index files, files with binary objects and log files from
> each other and place them on separate physical discs to improve performance.
> Now we're planning to use cluster server with external storage (HP MSA 1000).
> A technician, who was configuring the hardware, told me that in this
> configuration storage library segments presented to MSSQL server as discs are
> already spread on many physical discs and there is no reason now to put
> database files on different drives.
> The question is: is this true? Will it be good if I'll put all files on
> one logical disc and let storage library to manage data distridution across
> physical discs?
> Thanks.
> Serge Shakhov
|||Mike,
Is there a net guide somewhere on setting up log files and data optimally?
Thanks,
Mica
"Mike Epprecht (SQL MVP)" <mike@.epprecht.net> wrote in message
news:F43766EE-6358-4515-B6A3-7705B516DA18@.microsoft.com...[vbcol=seagreen]
> Hi
> Ideally, the log and data portion of the database should be on different
> LUNs ("storage library segments") and the Log should be on RAID-1 or
> RAID-10.
> RAID-5 is not optimal for the Log due to it's high latency. Actually, with
> the price of storage today, RAID-5 has no place near a IO intensive
> server.
> Further to that, if you get presented 5 LUNs, and then present them to SQL
> Server as only one disk, generally, you do not use up all the storage, so
> the
> first 2 or 3 of the LUNS will have all the traffic, and there is no data
> on
> the other LUNs, so they get no traffic. You don't want this. You rather
> have
> 5 database files, one on each LUN so that all the drives are busy.
> Without knowing exactly how the LUNs are mapped to the physical drives and
> how you want to map to LUNs to OS drives, I can't pass more comment.
> --
> Mike Epprecht, Microsoft SQL Server MVP
> Zurich, Switzerland
> MVP Program: http://www.microsoft.com/mvp
> Blog: http://www.msmvps.com/epprecht/
>
> "Serge Shakhov" wrote:

Data files location.

Hello.
I have large database with very high workload (100 trans/sec avg.)
When database files were located on local disks on the server I tried to
part data files, index files, files with binary objects and log files from
each other and place them on separate physical discs to improve performance.
Now we're planning to use cluster server with external storage (HP MSA 1000)
.
A technician, who was configuring the hardware, told me that in this
configuration storage library segments presented to MSSQL server as discs ar
e
already spread on many physical discs and there is no reason now to put
database files on different drives.
The question is: is this true? Will it be good if I'll put all files on
one logical disc and let storage library to manage data distridution across
physical discs?
Thanks.
Serge ShakhovHi
Ideally, the log and data portion of the database should be on different
LUNs ("storage library segments") and the Log should be on RAID-1 or RAID-10
.
RAID-5 is not optimal for the Log due to it's high latency. Actually, with
the price of storage today, RAID-5 has no place near a IO intensive server.
Further to that, if you get presented 5 LUNs, and then present them to SQL
Server as only one disk, generally, you do not use up all the storage, so th
e
first 2 or 3 of the LUNS will have all the traffic, and there is no data on
the other LUNs, so they get no traffic. You don't want this. You rather have
5 database files, one on each LUN so that all the drives are busy.
Without knowing exactly how the LUNs are mapped to the physical drives and
how you want to map to LUNs to OS drives, I can't pass more comment.
Mike Epprecht, Microsoft SQL Server MVP
Zurich, Switzerland
MVP Program: http://www.microsoft.com/mvp
Blog: http://www.msmvps.com/epprecht/
"Serge Shakhov" wrote:

> Hello.
> I have large database with very high workload (100 trans/sec avg.)
> When database files were located on local disks on the server I tried to
> part data files, index files, files with binary objects and log files from
> each other and place them on separate physical discs to improve performanc
e.
> Now we're planning to use cluster server with external storage (HP MSA 100
0).
> A technician, who was configuring the hardware, told me that in this
> configuration storage library segments presented to MSSQL server as discs
are
> already spread on many physical discs and there is no reason now to put
> database files on different drives.
> The question is: is this true? Will it be good if I'll put all files on
> one logical disc and let storage library to manage data distridution acros
s
> physical discs?
> Thanks.
> Serge Shakhov|||Mike,
Is there a net guide somewhere on setting up log files and data optimally?
Thanks,
Mica
"Mike Epprecht (SQL MVP)" <mike@.epprecht.net> wrote in message
news:F43766EE-6358-4515-B6A3-7705B516DA18@.microsoft.com...[vbcol=seagreen]
> Hi
> Ideally, the log and data portion of the database should be on different
> LUNs ("storage library segments") and the Log should be on RAID-1 or
> RAID-10.
> RAID-5 is not optimal for the Log due to it's high latency. Actually, with
> the price of storage today, RAID-5 has no place near a IO intensive
> server.
> Further to that, if you get presented 5 LUNs, and then present them to SQL
> Server as only one disk, generally, you do not use up all the storage, so
> the
> first 2 or 3 of the LUNS will have all the traffic, and there is no data
> on
> the other LUNs, so they get no traffic. You don't want this. You rather
> have
> 5 database files, one on each LUN so that all the drives are busy.
> Without knowing exactly how the LUNs are mapped to the physical drives and
> how you want to map to LUNs to OS drives, I can't pass more comment.
> --
> Mike Epprecht, Microsoft SQL Server MVP
> Zurich, Switzerland
> MVP Program: http://www.microsoft.com/mvp
> Blog: http://www.msmvps.com/epprecht/
>
> "Serge Shakhov" wrote:
>

Data files in Flash Drive

Hi friends,
i want to know something abt sql server installation and database properties as under.
1) how much disk space reqd by multiuser sqlserver 2000 db to install ?
2) is it possible to install sql 2K on Flash Drive ( gen connect at USB) ?
3) When v create a database user Enterprise Manager , which files created by database ?
4) If i Know datafiles name of a database e.g. pubs , and if v copied on cd and paste on other system which has sql 2K install , does those database works ?
5) is it possible to create database on flash drive ?

thanx in advance.Come on...are these trick questions?|||I suppose it could be done, but you would have to be very sure that you properly detach the database before someone goes and unplugs the USB drive. I think you would set yourself up for a heck of a lot more user errors than SQL Server errors this way.

Data files from Database Object

The database object contains a member 'get_LogFiles' that returns a nice collection of the database's logfiles. I can't seem to find the comparable member to return the collection of datafiles. If someone can point me in the right direction, I would be most grateful

That's because log files do not reside in filegroups.

Check out the filegroup property, this contains a collection of data files.

WesleyB

Visit my SQL Server weblog @. http://dis4ea.blogspot.com

sql

data files filling up algorithm

Hi,
I have an sql database which has 3 datafiles belonging to the same filegroup. Could anyone tell me in what fashion the datafiles will fillup.
RegardsEqually in proportion
"ramy" <anonymous@.discussions.microsoft.com> wrote in message
news:162788A4-56D3-4BD0-8B42-15C0C740C85D@.microsoft.com...
> Hi,
> I have an sql database which has 3 datafiles belonging to the same
filegroup. Could anyone tell me in what fashion the datafiles will fillup.
> Regards|||As Hassan suggest, the algorythm is called "proportional fill"... SQL tries
to keep EACH data file the same percentage full... So it will add new
records to the data files which are less full, and when they become equally
full, a round robin type approach will keep the data files equally (by
percentage) full.
--
Wayne Snyder, MCDBA, SQL Server MVP
Computer Education Services Corporation (CESC), Charlotte, NC
www.computeredservices.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"ramy" <anonymous@.discussions.microsoft.com> wrote in message
news:162788A4-56D3-4BD0-8B42-15C0C740C85D@.microsoft.com...
> Hi,
> I have an sql database which has 3 datafiles belonging to the same
filegroup. Could anyone tell me in what fashion the datafiles will fillup.
> Regards

Data Files and one FileGroup

Hi,
Is it OK if we have one FileGroup but 3 data files in different disk drives?
We have a database of size 150G, two data fils are in the same disk drive
and the third data file is in a different disk driver. All are in the same
filegroup.
Shouldn't we create another file group for the third data file?
Thanks,
RosieRosie,
You're probably fine. Multiple files in a filegroup is common. MS
recommends one file per physical processor to help parrallelism. One thing
to look out for is for best performance you want the files to file at the
same rate. Autogrow and adding additional files often leads to hot spots on
the IO subsystem.
"Rosie" <Rosie@.discussions.microsoft.com> wrote in message
news:D194C8A5-5B94-4CBA-A994-4E78EA69E6B9@.microsoft.com...
> Hi,
> Is it OK if we have one FileGroup but 3 data files in different disk
> drives?
> We have a database of size 150G, two data fils are in the same disk drive
> and the third data file is in a different disk driver. All are in the same
> filegroup.
> Shouldn't we create another file group for the third data file?
> Thanks,
> Rosie
>
>|||inline
--
Sunil Agarwal (MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.
"Rosie" <Rosie@.discussions.microsoft.com> wrote in message
news:D194C8A5-5B94-4CBA-A994-4E78EA69E6B9@.microsoft.com...
> Hi,
> Is it OK if we have one FileGroup but 3 data files in different disk
> drives?
sunila> Yes. This will help you distribute the IO load across multiple
spindles.
> We have a database of size 150G, two data fils are in the same disk drive
> and the third data file is in a different disk driver. All are in the same
> filegroup.
Sunila> I will be curious to know why created two files belonging to same
file group on the same disk?
> Shouldn't we create another file group for the third data file?
Sunila> SQL Server allows creating file group that contains files from one
or more physical disks.
> Thanks,
> Rosie
>
>|||> You're probably fine. Multiple files in a filegroup is common. MS recommends one file per
> physical processor to help parrallelism.
Interesting... Do you have a link to that statement? So far, the only thing I've seen is that you
might want to consider the number of physical disks. Somewhere between 1 file per disk to 1 file per
8 disks. MS haven't given out a firm recommendation as it is very hw dependent.
--
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Danny" <someone@.nowhere.com> wrote in message news:CIPef.19373$%t4.15694@.trnddc07...
> Rosie,
> You're probably fine. Multiple files in a filegroup is common. MS recommends one file per
> physical processor to help parrallelism. One thing to look out for is for best performance you
> want the files to file at the same rate. Autogrow and adding additional files often leads to hot
> spots on the IO subsystem.
>
> "Rosie" <Rosie@.discussions.microsoft.com> wrote in message
> news:D194C8A5-5B94-4CBA-A994-4E78EA69E6B9@.microsoft.com...
>> Hi,
>> Is it OK if we have one FileGroup but 3 data files in different disk drives?
>> We have a database of size 150G, two data fils are in the same disk drive
>> and the third data file is in a different disk driver. All are in the same
>> filegroup.
>> Shouldn't we create another file group for the third data file?
>> Thanks,
>> Rosie
>>
>

Data Files and one FileGroup

Hi,
Is it OK if we have one FileGroup but 3 data files in different disk drives?
We have a database of size 150G, two data fils are in the same disk drive
and the third data file is in a different disk driver. All are in the same
filegroup.
Shouldn't we create another file group for the third data file?
Thanks,
Rosie
Rosie,
You're probably fine. Multiple files in a filegroup is common. MS
recommends one file per physical processor to help parrallelism. One thing
to look out for is for best performance you want the files to file at the
same rate. Autogrow and adding additional files often leads to hot spots on
the IO subsystem.
"Rosie" <Rosie@.discussions.microsoft.com> wrote in message
news:D194C8A5-5B94-4CBA-A994-4E78EA69E6B9@.microsoft.com...
> Hi,
> Is it OK if we have one FileGroup but 3 data files in different disk
> drives?
> We have a database of size 150G, two data fils are in the same disk drive
> and the third data file is in a different disk driver. All are in the same
> filegroup.
> Shouldn't we create another file group for the third data file?
> Thanks,
> Rosie
>
>
|||inline
Sunil Agarwal (MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.
"Rosie" <Rosie@.discussions.microsoft.com> wrote in message
news:D194C8A5-5B94-4CBA-A994-4E78EA69E6B9@.microsoft.com...
> Hi,
> Is it OK if we have one FileGroup but 3 data files in different disk
> drives?
sunila> Yes. This will help you distribute the IO load across multiple
spindles.

> We have a database of size 150G, two data fils are in the same disk drive
> and the third data file is in a different disk driver. All are in the same
> filegroup.
Sunila> I will be curious to know why created two files belonging to same
file group on the same disk?
> Shouldn't we create another file group for the third data file?
Sunila> SQL Server allows creating file group that contains files from one
or more physical disks.

> Thanks,
> Rosie
>
>
|||> You're probably fine. Multiple files in a filegroup is common. MS recommends one file per
> physical processor to help parrallelism.
Interesting... Do you have a link to that statement? So far, the only thing I've seen is that you
might want to consider the number of physical disks. Somewhere between 1 file per disk to 1 file per
8 disks. MS haven't given out a firm recommendation as it is very hw dependent.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Danny" <someone@.nowhere.com> wrote in message news:CIPef.19373$%t4.15694@.trnddc07...
> Rosie,
> You're probably fine. Multiple files in a filegroup is common. MS recommends one file per
> physical processor to help parrallelism. One thing to look out for is for best performance you
> want the files to file at the same rate. Autogrow and adding additional files often leads to hot
> spots on the IO subsystem.
>
> "Rosie" <Rosie@.discussions.microsoft.com> wrote in message
> news:D194C8A5-5B94-4CBA-A994-4E78EA69E6B9@.microsoft.com...
>