Hard Drive Space and Disk Caching

Dear friends
I have what may be a basic question to most folks here. Does SQL manage disk caching across partitions or hard drives for greatest efficiency
Basically I have a small C drive partition reserved for basic operating systems stuff. All program and data files, including SQL and databases are on the much larger D and E drives. Would there ever be an issue of the C drive not being large enough and causing SQL to slow down or not perform as well
Someone told me that all disk caching happens on the C drive, which doesn't make sense to me. It seems to me that SQL would be smart enough to use other physical drive resources as needed. They are encouraging us to use Partition Magic to expand the size of our C drive (which currently has about 1 Gig available, to be expanded to between 5 and 10 Gig)
Does this seem like good advice?I do not understand what they are saying - by definition caching is =holding data locally for fast access, SQL Server holds data in memory =having read it from disc. What drive letter is utterly irrelevant to it =(and from a data management perspective the whole concept of drive =letters is horrid!)
SQL Server caching is fine across any drive letter - it cares little =about such things. I have one system where C is getting really tight =(due to successive service packs and fixes) but all the SQL server =stuff, pagefile etc is elsewhere and we have noticed no performance =problems.
Mike John
"Kevin" <anonymous@.discussions.microsoft.com> wrote in message =news:4376A82B-AC21-463C-BCDD-B124FE980C98@.microsoft.com...
> Dear friends,
> > I have what may be a basic question to most folks here. Does SQL =manage disk caching across partitions or hard drives for greatest =efficiency?
> > Basically I have a small C drive partition reserved for basic =operating systems stuff. All program and data files, including SQL and =databases are on the much larger D and E drives. Would there ever be an =issue of the C drive not being large enough and causing SQL to slow down =or not perform as well?
> > Someone told me that all disk caching happens on the C drive, which =doesn't make sense to me. It seems to me that SQL would be smart enough =to use other physical drive resources as needed. They are encouraging =us to use Partition Magic to expand the size of our C drive (which =currently has about 1 Gig available, to be expanded to between 5 and 10 =Gig).
> > Does this seem like good advice?|||Kevin,
First off sql servers cache is a memory based cache not a disk one. The
cache your thinking of is the OS cache or virtual memory. A properly tuned
Sql Server will not use this cache at all. And yes it is usually on the c:
drive. Second it sounds like your drives are all logical drives on the same
physical hard drive. If this is the case it doesn't matter since it is all
the same physical drive. Having multiple logical partitions is more of a
hindrance than a help in that case.
--
Andrew J. Kelly
SQL Server MVP
"Kevin" <anonymous@.discussions.microsoft.com> wrote in message
news:4376A82B-AC21-463C-BCDD-B124FE980C98@.microsoft.com...
> Dear friends,
> I have what may be a basic question to most folks here. Does SQL manage
disk caching across partitions or hard drives for greatest efficiency?
> Basically I have a small C drive partition reserved for basic operating
systems stuff. All program and data files, including SQL and databases are
on the much larger D and E drives. Would there ever be an issue of the C
drive not being large enough and causing SQL to slow down or not perform as
well?
> Someone told me that all disk caching happens on the C drive, which
doesn't make sense to me. It seems to me that SQL would be smart enough to
use other physical drive resources as needed. They are encouraging us to
use Partition Magic to expand the size of our C drive (which currently has
about 1 Gig available, to be expanded to between 5 and 10 Gig).
> Does this seem like good advice?|||Dear Andriew and Mike,
Thank you both for your responses. It seems to me, from them, that we do not have an immediate need to re-partition our hard drive.
I did wonder what you had in mind Andrew, though, when you said:
"Having multiple logical partitions is more of a hindrance than a help in that case."
Pardon my naivete. Thanks!
In Peace,
K.|||Two things that I see often. One is that by having several logical drives
it tends to give the impression there are multiple physical drives. For
someone not familiar with the hardware they may make assumptions that are
wrong based on this. The other is that by having multiple logical
partitions you effectively limit how much space you have in each. Where as
if it was all one logical partition you don't have to worry about running
out of room until you hit the disk limit, not the partition limit. Hope
that helps.
--
Andrew J. Kelly
SQL Server MVP
"Kevin" <anonymous@.discussions.microsoft.com> wrote in message
news:41D04118-B9C2-45BD-8D81-1179187976F6@.microsoft.com...
> Dear Andriew and Mike,
> Thank you both for your responses. It seems to me, from them, that we do
not have an immediate need to re-partition our hard drive.
> I did wonder what you had in mind Andrew, though, when you said:
> "Having multiple logical partitions is more of a hindrance than a help in
that case."
> Pardon my naivete. Thanks!
> In Peace,
> K.
>