Below are several tuning considerations for various platforms. Some of the information may be outdated, however updated information will be provided as it becomes available.
Information is provided for the following clients:
Keep in mind that using NTFS on the TSM client does cause a performance degradation for small file workloads relative to FAT, because of the need to check security information during backup, and the impact of the NTFS filesystem recovery capability during restore.
NTFS file compression should not be used on disk volumes that are used by the TSM server, because of the potential for performance degradation.
For optimal TSM backup and restore performance when using a local client, use the namedpipes communication method.
For optimal TSM backup and restore performance with a large number of clients, consider using TSM client compression. Compressing the data on the client reduces demand on the network and on the TSM server. The reduced amount of data on the server continues to provide performance benefits whenever this data is moved, such as for storage pool migration and storage pool backup. However, client compression will significantly reduce the performance of each individual client, and the reduction will be more pronounced on the slowest client systems.
Anti-virus software can negatively impact backup performance
NetWare Cache Tuning
The following parameters in NetWare 4.10 (via SERVMAN utility) are tunable and have achieved very good results with TSM.
MTU
The MTU must be tuned to the appropriate size. In multi-network environments, data traveling from a network with a larger MTU to a smaller MTU, the IP layer must fragment the packet into smaller packets. This will cost the receiving system CPU time to reassemble the fragment packets.
The MTU size is configured by editing STARTUP.NCF (NetWare V3.x) or AUTOEXEC.NCF file (NetWare V4.x) as shown below:
TcpMSSinternetlimit
When data travels to a remote network or a different subnet, the TCPIP. NLMsets the MTU size to the default Maximum Segment Size (MSS) value of 536 bytes. The TcpMSSinternetlimit parameter can be used to override the default MSS value and to set a larger MTU. For NetWare v4.x with TCP/IP v3.0, setting TcpMSSinternetlimit off in SYS:\ETC\TCPIP.CFG will cause the TCPIP. NLM to use the MTU value specified in STARTUP.NCF file (maximum physical receive packet size). Also, note that the TcpMSSinternetlimit parameter is case sensitive. If this parameter is not specified correctly, it will be dropped automatically from the tcpip.cfg file by NetWare.
TCPIP.CFG
TcpMSSinternetlimit off
For NetWare v3.x, Novell patch TCP31A.EXE (for TCP/IP v2.75) can provide the same option.
On SunOS, the TCP/IP software parameters can be changed by editing the min inetinet/in_proto.c file in the release kernel build directory (usually/usr/sys). After changing the parameters, you need to rebuild the kernel. The parameters that can affect performance are:
tcp_default_mss
Specifies the default Maximum Segment Size (MSS) for TCP in bytes. The MSS is based on the Maximum Transmission Unit (MTU) size of the network if the destination is on the same network. To avoid fragmentation, the conservative value of 512 is used . For improved performance on Ethernet or Token-Ring, larger MSS values are recommended. (For example, settings of 1024, 1500, 2048, or 4096 can be used.) On Ethernet LANs, the largest MTU value is 1500.
tcp_sendspace
Specifies the number of bytes that the user can send to a TCP socket buffer before being blocked. The default values can be changed on a given socket with the SO_SNDBUF ioctl. The default value is 4096 Set this parameter to 16KB or 32KB.
tcp_recvspace
Specifies the number of bytes that the remote TCP can send to a TCP socket buffer before being blocked. The default values can be changed on a given socket with the SO_RCVBUF ioctl. The default value is 4096. Set this parameter to 16KB or 32KB.
Note: client tcpw of 32K for fddi and fast ethernet. Use 64K for Gigabit ethernet Further tuning considerations: