Speed Problem

vikram7_dabas

Dear concern
One of my client is using Nav 2009 SP1 IN Version on SQL Server 2008 and on OS Windows server 2008 R2 RAID1 and RAID5.DB is 50 GB and RAM is 14 GB.Sometimes, when a single user is posting output journal the n it is taking 2-4 hours to post 100 entries and sometimes it is very fast.What can be the problem?

Shonatina

SQL slows the processor down very badly...happens a lot to me!

kriki

You don't give a lot of info on your system, but I would start with checking these:

-Are you doing a regular indexrebuild on SQL?
-are your files fragmented?
-Are your DB-files and TL-file on different physical drives? And preferable NOT RAID5 or RAID6! Especially your TL should be on dedicated drives that are NOT RAID5 or RAID6!
-Are there other things running on the server that may take away resources from SQL?

vikram7_dabas

Dear Concern
Whats the process to reindex in SQL?
U mean we have to defragment drives on which we have DB files and TL Files(i.e., .mdf, .ndf, .ldf files) and we have to put .mdf,.ndf and .ldf files on different-2 drives?

vikram7_dabas

kriki wrote:

You don't give a lot of info on your system, but I would start with checking these:

-Are you doing a regular indexrebuild on SQL?
-are your files fragmented?
-Are your DB-files and TL-file on different physical drives? And preferable NOT RAID5 or RAID6! Especially your TL should be on dedicated drives that are NOT RAID5 or RAID6!
-Are there other things running on the server that may take away resources from SQL?

Dear Concern
U mean that our .mdf, .ndf, .ldf files should not be on RAID5,RAID1 AND RAID6 Drives? Am I right?

kine

vikram7_dabas wrote:

U mean that our .mdf, .ndf, .ldf files should not be on RAID5,RAID1 AND RAID6 Drives? Am I right?

Who was talking about RAID1? Just RAID5 and 6 was mentioned... :whistle:

David_Singleton

What's wrong with RAID 6?

kine

RAID6 is RAID5 with additional parity set (it have same READ speed as RAID5 but worse write because two parity sets must be calculated and wtritten).

David_Singleton

kine wrote:

RAID6 is RAID5 with additional parity set (it have same READ speed as RAID5 but worse write because two parity sets must be calculated and wtritten).

I had a client with a 700gig db on raid 6.

David_Singleton

David Singleton wrote:

kine wrote:

RAID6 is RAID5 with additional parity set (it have same READ speed as RAID5 but worse write because two parity sets must be calculated and wtritten).

I had a client with a 700gig db on raid 6.

Mind you I also have a client MUCH MUCH bigger running on RAID5 :-$ So maybe I am a bit crazy.

kriki

Index rebuild: see maintenance plans: indexrebuild.
You can download this (free) ebook: http://www.simple-talk.com/books/sql-books/brads-sure-guide-to-sql-server-maintenance-plans/.
It is a good help to start you with maintenance plans.

And RAID: avoid RAID5 and RAID6 for databases. The best are RAID1 or RAID10.

FDickschat

If it happens only seldomly it might also be autogrow of the SQL DB or the Log (although a delay of 2-4 hours seems way too high for that).
Search the forum for DB setup. You will find some good articles about how to setup the disks.

It might be hardware, software, blockings,... too many things to name them all.

stryk

Just my two cents regarding RAID5, RAID5DP or RAID6:

IMHO this is a real pain if that physical disk-array is directly attached to the server - reading data is OK, as good as with RAID10, but writing sucks due to creating/writing the parity information.

But: all real SAN solutions are using RAID5 & Co., of course, as "mirroring" (as RAID1 or 10) would waste too many precious disks. With real SAN solutions this works good, because the transactions are buffered by huge NVRAM caches of the Fiber Channel headers. As long as sufficient cache is available (we're talking about 2GB and up) no performance issues should occur ... (except if some other SAN config is wrong) ...

@David: are your "RAID5 customers" using SAN or direct volumes? Recently I've heard that actual RAID5 controllers perform better; I'd appreciate to get further info on this!

And back to the original problem: I suggest to search MIBUSO about "SQL Performance" :whistle:

kriki

stryk wrote:

IMHO this is a real pain if that physical disk-array is directly attached to the server - reading data is OK, as good as with RAID10, but writing sucks due to creating/writing the parity information.

Actually, RAID5 is faster than RAID10 for reading. But writing does suck!

A SAN with lots of writecache can handle some writing before getting into performance problems.
BUT:
-mosts SAN's have max 20% write cache and 80% read cache that doesn't serve anything for SQL. SQL needs write cache on the SAN (SQL has its own readcache that is a lot more better for that purpose).
-If the SAN is configured correctly, it can withstand write peaks but if those writes are sustained, the write cache will fill up and performance will drop.

vikram7_dabas

Dear concern
What do u mean by SAN?Please explain me .I shall be very thankful to you.

FDickschat

Your Signature reads "NAV technical consultant" and you don't know what a SAN is??? :-k

David_Singleton

vikram7_dabas wrote:

Dear concern
What do u mean by SAN?Please explain me .I shall be very thankful to you.

Vikram, I am very concerned for your customer now. They have paid (and I assume) continue to pay you and your company a lot of money for the technical skills that you have. I don't think you should be doing this job alone. If your company does not have technically qualified personnel, then really they should not be selling Navision, but at least to save this client you should look for external resources to help fix this.

aliennav

FDickschat wrote:

Your Signature reads "NAV technical consultant" and you don't know what a SAN is??? :-k

Hey David
I appriciate your knowledge and I am "FAN" of that.
But I suppose it's not necessary that BIll gates knows how to code for windows........still he's the owner..

:thumbsup:

kine

aliennav wrote:

FDickschat wrote:

Your Signature reads "NAV technical consultant" and you don't know what a SAN is??? :-k

Hey David
I appriciate your knowledge and I am "FAN" of that.
But I suppose it's not necessary that BIll gates knows how to code for windows........still he's the owner..

:thumbsup:

Yes, he is OWNER, he do not need to know that. You are technical consultant, you should know that or you need to know how to find the answer on that. It is not problem todays... ;-)

aliennav

kine wrote:

aliennav wrote:

FDickschat wrote:

Your Signature reads "NAV technical consultant" and you don't know what a SAN is??? :-k

Hey David
I appriciate your knowledge and I am "FAN" of that.
But I suppose it's not necessary that BIll gates knows how to code for windows........still he's the owner..

:thumbsup:

Yes, he is OWNER, he do not need to know that. You are technical consultant, you should know that or you need to know how to find the answer on that. It is not problem todays... ;-)

:thumbsup: