Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computer Certification > MCSE > 70-229 and SQL file placement

Reply
Thread Tools

70-229 and SQL file placement

 
 
Dale
Guest
Posts: n/a
 
      07-24-2004
I'm reading Thomas Moore's book for 70-229. It isn't as full of mistakes as
most study guides I have read, but some of what he says, I am just not too
sure about.

I'd like to get some feedback (arguments) going on SQL Server and file
placement. Of course, all this discussion should be based on Microsoft's
perceptions and the exam, which, I would bet money, are way out of step with
state of the art RAID systems in the real world.

Moore says that tables that are mostly constant but read a lot should be on
RAID 5. I think they should be on RAID 1, mirroring. Mirroring allows two
threads to access the disk mechanics simultaneously. RAID 5, on the other
hand, is faster for writing because it can drop off a few bytes on one
drive, then while the mechanics are doing their part, the controller has
already dropped off bytes to the other drives in the stripe. Do you agree?

He says that the log files should be on RAID 1 for reliability because they
are written to often. Well, any RAID except 0 gives data protection in the
event of a disk failure, but RAID 1 requires 2 writes for each single block
of data being saved. His reasoning is that calculating parity on a RAID 5
takes time. I think that calculating parity on a quality hardware RAID
controller will always be faster (a few hundred processor cycles at most)
than any hard drive with moving parts could possibly be. What do you think?

Or more important... what do you think Microsoft thinks?

Dale Preston
MCSE, MCDBA, MCAD


 
Reply With Quote
 
 
 
 
jwk
Guest
Posts: n/a
 
      07-24-2004
Moore is right; raid 1 is faster than raid 5. raid 1 takes no
calculation, just simply read and write with cloning the signal to a
second harddrive. your suggestion that a mirror set could handle two
threads is not true; al requests are send to both drives. That's why they
call it mirroring.

Raid 5 always asks some calculation, no matter how much hardware you use
for building the raid.every write request takes some calculation.

If you want good performance on your logs, use raid 0+1; four drives
forming two pairs of raid 0, mirroring each other.

my 2p.

jwk

"Dale" <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> I'm reading Thomas Moore's book for 70-229. It isn't as full of
> mistakes as most study guides I have read, but some of what he says, I
> am just not too sure about.
>
> I'd like to get some feedback (arguments) going on SQL Server and file
> placement. Of course, all this discussion should be based on
> Microsoft's perceptions and the exam, which, I would bet money, are
> way out of step with state of the art RAID systems in the real world.
>
> Moore says that tables that are mostly constant but read a lot should
> be on RAID 5. I think they should be on RAID 1, mirroring. Mirroring
> allows two threads to access the disk mechanics simultaneously. RAID
> 5, on the other hand, is faster for writing because it can drop off a
> few bytes on one drive, then while the mechanics are doing their part,
> the controller has already dropped off bytes to the other drives in
> the stripe. Do you agree?
>
> He says that the log files should be on RAID 1 for reliability because
> they are written to often. Well, any RAID except 0 gives data
> protection in the event of a disk failure, but RAID 1 requires 2
> writes for each single block of data being saved. His reasoning is
> that calculating parity on a RAID 5 takes time. I think that
> calculating parity on a quality hardware RAID controller will always
> be faster (a few hundred processor cycles at most) than any hard drive
> with moving parts could possibly be. What do you think?
>
> Or more important... what do you think Microsoft thinks?
>
> Dale Preston
> MCSE, MCDBA, MCAD
>
>
>


 
Reply With Quote
 
 
 
 
Neil
Guest
Posts: n/a
 
      07-27-2004
babbling on and on again "=?Utf-8?B?Qm9iYnk=?="
<(E-Mail Removed)> spewed in
news(E-Mail Removed):

> Moore is right in saying that RAID 1 has better write performance but
> RAID 5 has excellent read performance.


but the point of an OLTP database would be to write almost as much as you
read. If you want decent performance in the real world I am still
sticking with my RAID 0+1 and if I am forced into using a raid 5 system
it better be for DSS or some crappy little db that no one will notice how
bad it performs for I,U,D...hardware or software RAID be damned, RAID 0+1
HW still kicks HW RAID 5's a$$...(and I would like to see you do SW RAID
0+1 on an MS box <VBEG>)

--
Neil MCNGP #30
Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.

When I die, I want to die like my grandfather-who died peacefully in
his sleep. Not screaming like all the passengers in his car.
 
Reply With Quote
 
The Poster Formerly Known as Kline Sphere
Guest
Posts: n/a
 
      07-27-2004
>but the point of an OLTP database would be to write almost as much as you
>read. If you want decent performance in the real world I am still
>sticking with my RAID 0+1 and if I am forced into using a raid 5 system
>it better be for DSS or some crappy little db that no one will notice how
>bad it performs for I,U,D...hardware or software RAID be damned, RAID 0+1
>HW still kicks HW RAID 5's a$$...(and I would like to see you do SW RAID
>0+1 on an MS box <VBEG>)


nah, tera ramsan the way to go!

Kline Sphere (Chalk) MCNGP #3
 
Reply With Quote
 
Neil
Guest
Posts: n/a
 
      07-27-2004
babbling on and on again The Poster Formerly Known as Kline Sphere <.>
spewed in news:(E-Mail Removed):

> tera ramsan


ok, fine. then with conventional disks 0+1 kicks a$$.

--
Neil MCNGP #30
Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.

When I die, I want to die like my grandfather-who died peacefully in
his sleep. Not screaming like all the passengers in his car.
 
Reply With Quote
 
The Poster Formerly Known as Kline Sphere
Guest
Posts: n/a
 
      07-27-2004
>> tera ramsan
>
>ok, fine. then with conventional disks 0+1 kicks a$$.


touchy, touchy...

Kline Sphere (Chalk) MCNGP #3
 
Reply With Quote
 
Ken Briscoe
Guest
Posts: n/a
 
      07-27-2004
"Bobby" <(E-Mail Removed)> wrote in message
news(E-Mail Removed)...

<snip repost of post that was a post similar to a post made 13 hours ago>

We get the point, Bobby. Good advice, just too much of it.

--

KB - MCNGP "silent thug" #26

first initial last name AT hotmail DOT com


 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
O.T. optimising file placement Roedy Green Java 20 02-25-2012 01:15 PM
SQL Reference, SQL Queries, SQL help ecoolone ASP .Net 0 01-03-2008 10:58 AM
VPN 3000 and PIX placement w/InternetRouter william Cisco 3 05-12-2005 05:40 PM
firewall placement and choice of firewalls Joe Dewberry Cisco 0 12-09-2003 05:39 PM
Order and placement of tags Tony Cooper HTML 14 09-08-2003 08:05 AM



Advertisments