Posted by Tony Rogerson on 12/02/06 19:42

If you create multiple files then a thread is spawned per file.

You really need to test to see if your system benefits from such a
configuration.

The other thing to think of with multiple files (not specifically file
groups because thats something different) is that each file has multiple
IAMS so you get less contention on object creation which is why there is a
recommendation to have a file per cpu on tempdb.

The other thing to think about is the system partition (usually C:) has a
default allocation size of 4KB which cannot be changed; the recommendation
is that when you format your own partition (so don't put the database/logs
on C:) that you match the allocation size (FORMAT /A) to the stripe size of
the RAID controller - usually you set it to 64KB - that's DELL's
recommendation for their equipment.

--
Tony Rogerson
SQL Server MVP
http://sqlblogcasts.com/blogs/tonyrogerson - technical commentary from a SQL
Server Consultant
http://sqlserverfaq.com - free video tutorials


"rcamarda" <robert.a.camarda@gmail.com> wrote in message
news:1165084494.749016.224450@73g2000cwn.googlegroups.com...
> Tony,
> I like to use RAID 10 when I can, much faster than 5.
> Are you saying that even thou there is a single logical drive that the
> raid controller built, there is a difference at the windows level when
> we create seperate O/S logical drives? Or, are you refering back to the
> Raid 5 vs. Raid 1??
> I'd like to clarity on this point as I am going to building new
> servers.
> Tony Rogerson wrote:
>> RAID 5 should be no where near a database server now-a-days; use RAID 1
>> or
>> preferably RAID 10.
>>
>> Each file spawns a thread out to the OS so yes there is benefit; you have
>> to
>> be aware that the two threads will be doing async io so on a poor io
>> subsystem or one that is loaded you can actually hurt performance by
>> doing
>> it.
>>
>> --
>> Tony Rogerson
>> SQL Server MVP
>> http://sqlblogcasts.com/blogs/tonyrogerson - technical commentary from a
>> SQL
>> Server Consultant
>> http://sqlserverfaq.com - free video tutorials
>>
>>
>> <justin.merth@gmail.com> wrote in message
>> news:1165001018.950900.59520@f1g2000cwa.googlegroups.com...
>> > Is there any benefit in creating seperate file groups for a partitioned
>> > table on a multi-processor server with RAID5 and 1 Logical Drive?
>> >
>

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