Hard Disk Configuration fro Navision - SQL V 4 sp2

Dear all,

I downloaded the hard disk configuration from the forum and sent it to my NSC to confirm that server set-up required - I asked numerous times for a config but it never appeared (All they said was don’t use RAID 5).

They came back saying that this was for the native Navision database and not SQL.

They now suggest the following in terms of logical configuration

Drives 0 & 1 as a mirrored pair logical drive C with OS & Navision executable

Drives 2 & 3 as a mirrored pair logical drive L as Navision database part 1

Drives 4 & 5, 6 & 7 and 8 & 9 as mirrored pairs as logical drive K Navision SQL database

The physical configuration is the same as that on the download, phew!.

I was just wondering if anyone has any view on this

If you are wondering the server is 3.2 Intel 5060 Dual Core dual processors with 8 Gig of RAM, so I think we should be okay n that side for our less than 50 user system [:D]

All comments appreciated.

Chris

I don’t see any mention of the SQL transaction log. I would suggest a dedicated RAID 1 pair for each database. Also you will need Windows Server (Enterprise Edition) to take advantage of the 8 GB RAM

How large is the database?

Drives 4 & 5, 6 & 7 and 8 & 9 as mirrored pairs as logical drive K Navision SQL database

These drives are the most important for performance. They should be configured as RAID 10. The more drives the better (budget). Also attach to a good RAID controller.

Hope this is helpful

The transaction log is on the mirror of drives 2 & 3

Thanks for the information on Windows server, I love Microsofts licnesing so much [:|]

Drives 4 through 9 are in a RAID 10 configuration. All the disks are 73GB 15k SAS and our estimates are the database size will be very small, 5-10GB. At the moment I have the approval and budget to buy a decent machine, but as we all know in 12 - 18 months things can change. The transaction volumes are small as this is a service company, so no inventory, warehousing etc.

My plan is to ensure that performance cannot be ut down to the server or the infrastructure, now all I need is the NSC to do a good job with us on the set-up [:P]

Many thanks again

The transaction log needs to be on a dedicated drive set (RAID 1). That means no other files on that RAID set. Placing the transaction log on a shared drive will seriously impact write performance.

Just to clarify the logs are a separate mirrored paired (Drives 2 & 3) with logical drive L, the database is drive is logical drive K with disks 4 through 9.

Many thanks again for your feedback, I hope I am clearer now(or not missing something [:S] )

Where are the SQL system databases?

Use a 4 drive set configuration.

SET 1 (RAID 1)

O/S and program files

SET 2 (RAID 1 or small RAID 10)

SQL System DBs and Navision Primary Data file

SET 3 (RAID 1)

SQL Transaction log for Navision database.

SET 4 (RAID 10)

Navision secondary data file. (This is the big one).

Note: Sets 2 & 4 can be combined if budget is limited but this reduces recovery ability.

Okay now I am getting worried [:S] as we only seem to have three sets.

Drives 0 & 1 - OS & Navision executable (C:)

Under heading MS-SQL Cache

Drives 2 & 3 - Navision Database part 1 (L:)

Drives 4 - 9 - Navision SQL Database (K:)

So if I understand this correctly I am missing a pair of disks, which I guess would be the transaction logs, or they have combined the two of the sets.

Therefore

SET 1 - Drives 0 & 1

SET 2 - Drives 2 & 3

SET 3 - Drives 4 & 5 ( The missing set )

SET 4 - Drives 6 - 11 (Six disks)

Am I correct in understanding this ?

Once again many thanks for this ( RAID 5 is so much simpler lol)

Chris definitely you ned a seperate array for the transaction log:

Take a look at these posts that may clarify things a bit:

http://www.mbsonline.org/forum/topic.asp?TOPIC_ID=7093

http://www.mbsonline.org/forum/topic.asp?TOPIC_ID=14871

http://www.mbsonline.org/forum/topic.asp?TOPIC_ID=13413

http://www.mbsonline.org/forum/topic.asp?TOPIC_ID=15936

You don’t really need to sets of disks for the primary data file, you can also have that on the OS drive. This is the file that has the objects, not data. The data all goes into the secondary files, and that’s the one you have to have on mirrored pairs. Like bbrown says, you have to have a dedicated drive for the TL, and since you should back this up very regularly (like hourly), I don’t think it would be necessary to have it redundantly.

4 drive arrays sounds like a very big installation to me, this is not an average implementation.

David,

I am having the same problem of it asking me to be logged in, as you may remember I joined the forum after it was closed to new members on mbs.

When the diagram came through I assumed the transaction log was going to be placed on mirrored pair 2, but as babrown has shown it appears we are a mirror pair short.

What is frustrating is that with the specification of servers we have, and the NCS has seen this, it is obvious that money is not a constraining factor, especially not £500 for two disks. We continually asked for the correct confguration when they said that RAID 5 was a no goer, my IT managers preference, but then they didn’t give us any detailed configuration - thank goodness for this forum.

This is only a 42 user system at present, but to cater for growth (40% in the last two years) I have the ability to spend money on this equipment - within reason of course. Both the Navision box and the terminal services box are dual core dual processors with 8GB of RAM, no one spends £10k on hardware to skimp on two disks [:@]

Can you allow me access to the posts you have put on this thread.

Many thanks again

Chris

Daniel,

If I came to you and asked for a definitive solution would it be for a 4 drive set solution as described.

I look at what babrown suggests and it gives me a lot of comfort in terms of performance and resilience, though I know there are fail over points like one of the three disk controllers. In my experience with installs I look at the spec suggested and usually double it, budget permitting, and that usually does not mean doubling the price - for this install adequate server specs would come in at about £6-7k which is circa 4-5 days consulting time, in savings from the spec I have. When you look at it that way and it means, hopefully, there will be no questions about the server performance either at install or through the servers life it makes sense to me to spend the money upfront and then forget about the server. It then only needs the IT department to manage it.

There are some clients I know who will try and save a penny, even if we all know it will cost them a pound in the near future, luckily I have not had to eal with any of those, or I have a good set of justifications in my proposals.

Thanks again for your thoughts

Chris

David,

Thanks for sorting out my access to those old forum threads.

Chris

One more question and then I’ll rate this I promise [:)]

What version of Windows Server - 32 or 64 bit ??? Does going 64-bit open another can of worms ?

Many thanks

Chris

No I would probably advise a 3 set configuration. I would put the sys databases and the primary file for the NAV database on the OS set. Of course, when you grow and you experience SQL Server performance issues, you might want to consider dedicating a set for sys databases. It all helps for performance, but is not necessary unless you are talking about a bigger installation, and I can’t say anything about that because I don’t know how you will be using NAV. If you have the budget for it and you want to be ready for the future, the configuration that Brown suggests will keep you warm and cozy for a long time. We always tell customer to go as fancy as your budget allows you.

The reason why RAID 5 is not recommended is because of parity calculations. There is a cutover point where calculating parity holds up the writing. This is a known issue not only in NAV, but in all write intensive database apps, like ERP systems. RAID 5 is wonderful for apps that mostly read data, like data warehouses, not for apps that process and write large transaction volumes.

MSFT did some benchmark testing and determined that at around 10% system usage, RAID 5 starts slowing down NAV on large transaction volumes. This benchmark testing was done with large volumes of the same transaction, so maybe you particular situation would work fine with RAID 5. I’ve heard many people saying their RAID 5 does not have any issues. All around I would say follow MSFT guidelines and use RAID 1+0 (not 0+1).

Placing the primary NAV file on the OS set would be fine, if budget restrictions don’t allow for a 4th drive set. The idea is to place the 2 NAV data files on separate disk sets. If the 2 NAV data files are on separate drive sets and the RAID 10 set (secondary data - large) fails, you can still backup the active transaction log and recover to point-of-failure. If both files were on same drive (you loose both), then you can only restore to the point of the last transaction log backup.