NBU 的tune

Care should be taken when changing these values. For example, increasing the tape buffer size can cause some backups to run slower and there have been cases where there have been restore problems.

IMPORTANT:  After making any changes, it is vitally important to verify that the following tests can be completed successfully:

1. Run a backup
2. Restore data from the new backup created in step 1
3. Restore data from a backup created prior to the changes to SIZE_DATA_BUFFERS and NUMBER_DATA_BUFFERS

The number and size of the data buffers used by the NetBackup media server can be checked by looking in the bptm log file: 

12:02:55 [28551] <2> io_init: using 32768 data buffer size
12:02:55 [28551] <2> io_init: CINDEX 0, sched bytes for monitoring = 2000
12:02:55 [28551] <2> io_init: using 8 data buffers

or

15:26:01 [21544] <2> mpx_setup_restore_shm: using 12 data buffers, buffer size is 65536

Increasing the size and number of the data buffers will use up more shared memory, which is a limited system resource. The total amount of shared memory used is: (buffer_size * num_buffers) * drives * MPX. 

So, for two tape drives, each configured with an MPX of 4, and with 16 data buffers of 256 KB, the total shared memory usage would be:

(16 * 256k) * 2 * 4 = 32 MB (32768 KB)

Take into consideration the total system resources and the entire network.
The Maximum Transmission Unit (MTU) for the LAN may also have to be changed.

NOTE: For Digital Linear Tape (DLT) drives, the number that seems to give the best performance for SIZE_DATA_BUFFERS is 65536. Further performance improvements can be achieved by increasing the value in the NUMBER_DATA_BUFFERS file.

[color=Red]NUMBER_DATA_BUFFERS_DISK[/color]

和 NUMBER_DATA_BUFFERS
的用法相似,但,一般瓶颈不会再这里,所以不在重复

[color=Blue]2 Os kernel tune(unix)[/color]

Os 这里主要以solaris为例(比较熟)
Tune 也主要是 share memory
下面是一些参数和推荐tune

■[color=Red] Message queues[/color]

set msgsys:msginfo_msgmax = maximum message size
set msgsys:msginfo_msgmnb = maximum length of a message queue in
bytes. The length of the message queue is the sum of the lengths of all the
messages in the queue.
set msgsys:msginfo_msgmni = number of message queue identifiers
set msgsys:msginfo_msgtql = maximum number of outstanding messages
system-wide that are waiting to be read across all message queues.

■ [color=Red]Semaphores[/color]

set semsys:seminfo_semmap = number of entries in semaphore map
set semsys:seminfo_semmni = maximum number of semaphore identifiers
system-wide
set semsys:seminfo_semmns = number of semaphores system-wide
set semsys:seminfo_semmnu = maximum number of undo structures in
system
set semsys:seminfo_semmsl = maximum number of semaphores per id

set semsys:seminfo_semopm = maximum number of operations per semop
call
set semsys:seminfo_semume = maximum number of undo entries per