BEST PRACTICES GUIDE
M icrosoft
Exchange Server
2003/2007
Copyright © StorageCraft Pty Ltd 2010-2011
This document may not, in whole or part, be copied, photocopied, reproduced, translated, reduced or transferred to any electronic medium or machine-readable form without the prior consent in writing from StorageCraft.
THIS PUBLICATION IS PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THIS PUBLICATION COULD INCLUDE TECHNICAL INACCURANCIES OR TYPOGRAPHICAL ERRORS. CHANGES ARE PERIODICALLY ADDED TO THE INFORMATION HEREIN; THESE
CHANGES WILL BE INCORPORATED INTO NEW EDITIONS OF THE PUBLICATION. STORAGECRAFT MAY MAKE IMPROVEMENTS AND / OR CHANGES IN THE PRODUCT(S), AND / OR THE
PROGRAM(S) DESCRIBED IN THIS PUBLICATION AT ANY TIME.
StorageCraft, the ShadowProtect logo and ShadowProtect are the trademarks or registered trademarks of StorageCraft Technology Corporation, in the United States and / or in other countries. All other names and trademarks are the property of their respective owners.
Document ID: BP000002 Revision: 3
Date: 1 July 2011
Author(s): Jack Alsop & Matt Thompson-Moltzen StorageCraft Asia Pacific
For Technical Support contact your regional office:
North America
Table of Contents
Audience ... 5
Scope ... 5
Discussion ... 5
Disk and disk sub-system s ... 5
Exchange installation ... 6
Paging file ... 6
Exchange VSS w riter ... 6
Specific exam ples ... 7
Host SATA RAID solution ... 7
Add in SATA RAID solution ... 7
SCSI and SAS ... 7
References ... 8
Products affected ... 8
Platform s affected ... 8
Replaces article ... 8
Audience
This document is intended for an Exchange Administrator and it is a guide to ensure that your experience with ShadowProtect is as expected. The concepts discussed are specifically aimed at Microsoft Exchange Server 2003 and Microsoft Exchange Server 2007 and it is of little consequence whether the underlying platform is Windows Small Business Server 2003, Windows Small Business Server 2008 or Windows Server 2003 64-bit, Windows Server 2008 64-bit or Windows Server 2008 R2 as the concepts are the same.
The necessity of this document is based on the fact that a percentage of System Administrators and/or integrators do not spec their servers correctly and therefore suffer issues with performance, backups and more importantly recovery.
Scope
The scope of this document is designed to supply specific information so that backup operators can make a detailed, informed decision when configuring ShadowProtect backups of their Exchange servers. Areas covered will include Disks, Disk Queue Lengths (DQL) and the Exchange installation.
Discussion
The content of this document will be broken down into its discrete sections followed by specific examples.
Disk and disk sub-systems
The quality and your understanding of the entire disk sub-system is critical to your implementation of ShadowProtect. The differences between Host SATA RAID and an add in RAID controller with a dedicated CPU and memory utilising business grade SATA disk is like chalk and cheese. Obviously a SAS based server can ignore some of the following advice.
Disk Queue Lengths
Microsoft has a recommendation for Disk Queue Lengths (DQL) based on Current Disk Queue Length and it has a value of 2.
How do you determine your DQL? Run Performance Monitor and add the Physical Disk counter called Average Disk Queue Length (use this one instead of Current Disk Queue Length as it provides a more gradual response). Ensure that you pick the counter that relates to the spindles in question. After a period take the average value of this counter and subtract the number of spindles in the array and the resulting number must be less than 2. The greater the number, the less responsive the server and the longer it will take to create snapshots. This therefore means the longer it will take to create backups, thus exposing you to greater chances of failures.
6 | M icrosoft Exchange Server 2003/2007
pages of kernel memory. The chances of a failure of the backup for the second and then third volume increases dramatically as the DQL increases.
Exchange installation
Most Exchange Administrators install Exchange into the system volume (C: drive typically) and then shift the databases and associated log files to a separate drive(s) – this is normal and we will deal with the backup solutions soon.
However there is one thing that seems to get left behind and this is the “System Path Location” on Exchange Server 2003 or the “System Files Path” in Exchange Server 2007. These “System Paths” refer to two files – the e00.chk and tmp.edb. The e00.chk file is the check point file that records what log file has been committed into the database. The location of this file is critical for restores of the Exchange databases at some point in the future because if this file states that Exchange is up to a specific log file and the Exchange database thinks it has committed a different log file then corruption will occur. To shift these files to the same place as the database, use the Exchange Management Console – point to the correct Storage Group and right-click and select the correct option (usually the same place as if you were shifting the log files).
So based on the above, a correctly configured Exchange server will look similar to this configuration:
Figure 1: Correct configuration
Paging file
For best performance of Windows and to get the shortest snapshot time for ShadowProtect you should create a fixed size Paging File, twice the size of physical memory. For example if there is 3 GB of memory then you should set up a fixed size Paging File with the Initial size and Maximum size of 6 GiB or 6,144 MiB.
Exchange VSS writer
Specific examples
In the following examples, the e00.chk file is in the same location as the data (refer to figure 1).
Host SATA RAID solution
The system volume (C: drive) contains the operating system, D: drive contains the Exchange data and the F: drive contains the Exchange logs. In this scenario the server should be backed up using two separate jobs to minimise the potential failures and reduce the impact on the server.
Add in SATA RAID solution
Utilising quality add in RAID cards the operating system is on a mirror with the Exchange logs on another mirror and the Exchange databases on a RAID-5.
Find out what the DQL are on these three disks and if any is over the 2 mark then use two jobs to backup this server – one job for the operating system and the other to include both the log and database disks. However if the DQL is way under 2 then you can use one job to backup this server.
SCSI and SAS
8 | M icrosoft Exchange Server 2003/2007
References
Products affected
ShadowProtect Server Edition ShadowProtect SBS Edition
Platforms affected
Windows Small Business Server 2011 Windows Server 2008 R2
Windows Small Business Server 2008 Windows Server 2008
Windows Server 2003 R2
Windows Small Business Server 2003 Windows Server 2003
