HOWTO: Special considerations when deploying NetBackup Media Server Deduplication on Windows systems.


NetBackup Media Server Deduplication (MSDP) is a powerful feature whose full potential cannot be realized without considering the operating environment. Follow these considerations when configuring MSDP in a Windows environment.

- If Windows Server 2008 R2, ensure Service Pack 1 is installed (because SP1 provides kernel fixes for poor disk I/O and TCP fixes addressing network issues.)

- Ensure all HBA drivers/firmware is up to date.

- When formatting the NTFS volume in Windows, specify a 64K blocksize (default is 4096 bytes which can lead to poor performance).

- For the volume drive letter(s) hosting deduplication, deselect 'Allow Indexing Service to index this disk for fast file searching' in the Properties|General tab in Windows Explorer.

- Ensure any antivirus software is excluding all NetBackup/MSDP volumes/directories and ignoring all NetBackup processes and network traffic. Failure to do this can result in AV deleting dedup .bin files and performance issues.

- Change the power plan from Balanced to High Performance (Balanced is default):;en-US;2207548

- Consider disabling 8dot3 names and lastaccess via fsutil commands for the NTFS volumes hosting deduplication:

- Disk I/O testing should be performed to prove read/write of 200MB/sec or better using Microsoft's 'sqlio' tool for Windows. Then and only then should MSDP/PureDisk be installed/configured. Sqlio:
     - sample commands:
sqlio -kW -s600 -frandom -t1 -o1 -b64 -LS -Fparam.txt

sqlio -kW -s600 -frandom -t1 -o8 -b64 -LS -Fparam.txt

sqlio -kW -s600 -frandom -t1 -o1 -b128 -LS -Fparam.txt

sqlio -kW -s600 -frandom -t1 -o8 -b128 -LS -Fparam.txt

sqlio -kR -s600 -frandom -t1 -o1 -b64 -LS -Fparam.txt

sqlio -kR -s600 -frandom -t1 -o8 -b64 -LS -Fparam.txt

sqlio -kR -s600 -frandom -t1 -o1 -b128 -LS -Fparam.txt

sqlio -kR -s600 -frandom -t1 -o8 -b128 -LS -Fparam.txt

NOTE: The parameter file needs to contain the name of the file to get written to or read from depending on the command. The file should be sufficiently large as well - more than the size of the RAM installed if using internal disks or larger than the amount of cache on the disk array.

- DO NOT enable compression/encryption on NetBackup backup policies.

- Disable TCP Autotuning:

a) To check the current status, run:   netsh interface tcp show global

       Querying active state

       TCP Global Parameters
       Receive-Side Scaling State : enabled
       Chimney Offload State : enabled
        Receive Window Auto-Tuning Level : normal Add-On Congestion Control Provider : none ECN Capability : disabled RFC 1323 Timestamps : disabled

b) To disable autotuning, run:  netsh interface tcp set global autotuning=disabled
c) To re-enable autotuning, run:   netsh interface tcp set global autotuning=normal

- Enable RSS (Receive Side Scaling) and TCP offload for improved performance in Windows 2008 R2:
In some instances, disabling RSS and TCP offload are required to fix backups that fail with network status codes (eg. status 41), so this is included as an additional point of troubleshooting.  For the most part, they should be enabled.

- DO NOT configure MSDP on NetBackup (NBU) master servers, OpsCenter servers or servers that are the master and opscenter server. Performance suffers significantly, particularly during busy backup periods.

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