Netbackup running on Windows 2008 R2 platform may encounter slow performance

Article: 100004070
Last Published: 2013-08-28
Ratings: 0 0
Product(s): NetBackup & Alta Data Protection

Problem

The Windows 2008 R2 x64 platform may encounter slower backup performancing using Netbackup when running local backups. There are 3 known issues that have affected NetBackup running on Windows 2008 R2 platforms.

 

Solution

1. The first is related to the Windows 2008 R2 kernel. Under heavy I/O the kernel may not perform as expected. The cause of this issue is documented in Microsoft KB article 982383, which says that a computer with heavy I/O may encounter decreased performance. The configuration encountered was:

- a Netbackup Media Server performing local backups to an LTO3 tape device, also when performing a local backup to a local disk storage unit.

- a NetBackup Media Server configured for Media Server Deduplication (MSDP) performing backups to local deduplication storage.

Specific rates of decrease were varied in labs, but decreases were encountered when heavy I/O was encountered as compared to Netbackup performance on Windows 2008 SP2 x64, and Windows 2003 x64

The version of ntoskrnl.exe that corrects this issue is 6.1.7600.20685. The following files included in the fix:


File name  File version  File size  Date Time   Platform
Ntoskrnl.exe  6.1.7600.20685  5,484,944  07-Apr-2010 07:51  x64
Ntkrnlpa.exe  6.1.7600.20685  3,955,080  07-Apr-2010 07:38  Not Applicable
Ntoskrnl.exe  6.1.7600.20685  3,899,784  07-Apr-2010 07:38  Not Applicable

To correct the issue for Windows Server 2008 R2, apply the latest Microsoft Service packs and Hotfixes that are available.

Microsoft claims that the issue will also impact Windows 7 x64 and x86 environments, and Windows 2008 R2 IA64 platforms.

 

2. The second known cause of NetBackup 7 performance problems is related to the Power Options settings in Windows. By default, Windows sets the Power Options to Balanced, which attempts to balance the power consumption of the hardware, but may sacrafice performance. Performance improvements have been found when the Power Options setting is set to High performance. These settings can be found in Windows Control Panel, Control Panel\All Control Panel Items\Power Options.

 

3. A third known cause of NetBackup performance problems is related to the TCP Chimney Offload and Recieve Side Scaling (RSS) settings of the network interface. In previous articles, such as 294308  and 29008 it was recommend to disable TCP Chimney Offload. For Windows 2008 R2 platforms, performance gains have been realized when TCP Chimney Offload is enabled. Microsoft article 912222 discusses TCP Chimney Offload and RSS and the purpose of each. Here is a summary from Microsoft article 912222:

"The architectural goal of the Scalable Networking initiative is to scale applications in the Windows family of operating systems to new levels of performance at a variety of cost points. Because of the variety of cost points and because of the variation in workload, the initiative includes the following two fundamental approaches:

Stateful offloads
Stateless offloads
TCP Chimney is a stateful offload. TCP Chimney offload enables TCP/IP processing to be offloaded to network adapters that can handle the TCP/IP processing in hardware. Each TCP Chimney offload-capable network adapter has a finite number of connections that it can support in hardware. TCP connections will be offloaded to hardware as long as the hardware can support these connections. After the hardware offload connection limit has been reached, all additional connections are handled by the host stack.

RSS and NetDMA are stateless offloads. Where multiple CPUs reside in a single computer, the Windows networking stack limits "receive" protocol processing to a single CPU. RSS resolves this issue by enabling the packets that are received from a network adapter to be balanced across multiple CPUs."

Microsoft has a brief presentation available on TCP Chimney Offload and RSS available at MSDN. The article is called "High-Performance Networking With NDIS, TCP Chimney Offload, and RSS". The presentation discusses these options in context of a 10GbE network. Other types of interfaces may not have these options available, but they are worth looking into.
 
Reference:
In addition to the Related Articles below, the following Microsoft documentation may provide additional insight into this issue:

High-Performance Networking With NDIS, TCP Chimney Offload, and RSS
 https://download.microsoft.com/download/5/b/9/5b97017b-e28a-4bae-ba48-174cf47d23cd/NET097_WH06.ppt
 

 

Applies To

Windows 2008 R2

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