Buffer setting suggestions?

[BRENDAN_GIESE]

We are running Netbackup 6.5.2a on Windows 2003x64 SP2. We have a StorageTek SL500 Tape Vault with 5 LTO4 drives. Our disk is on a Sun 6140 SAN with SATA drives on 4G fiber.  We've just started doing performance tuning with buffer settings to try and get some speed out of both our disk to disk and disk to tape backups. Our current settings are:

SIZE_DATA_BUFFERS_DISK          1048576
NUMBER_DATA_BUFFERS_DISK     64

SIZE_DATA_BUFFERS                 262144

NUMBER_DATA_BUFFERS             64 

NET_BUFFER_SZ                        1048576

Right now we get about 90Mb/s on a straight data copy disk to disk, and about 60Mb/s when using Netbackup, so clearly there is a bit more tuning we can do. Does anyone have a formula or reference other than repeated benchmarking to find the settings we should be putting in for our buffers to maximize the speed?

[Omar_Villa]

Try this:

Get the buffers setting from /usr/openv/netbackup/db/config

NET_BUFFER_SZ = 262144

NUMBER_DATA_BUFFERS = 128

SIZE_DATA_BUFFERS = 262144

SIZE_DATA_BUFFERS * NUMBER_DATA_BUFFERS * (NUMBER_OF_DRIVES * MPX)

262144 * 128 * (64 * 4) = 8192MB

grep -i shm "/etc/system"

set shmsys:shminfo_shmmax=6492782592

set shmsys:shminfo_shmmin=1

set shmsys:shminfo_shmmni=512

set shmsys:shminfo_shmseg=100

compare the total with the Shared Memory info and if is need perform the proper changes.

has you see the total memory you will need will depend of the number of drives and multiplexing, but buffers can be at the highiest level and you'll be fine, just pay attention to the size of VM that you have configured on your media server if is overloaded then you can crash it, has in this case that there ia 6GB of swap memory configured and total requried memory by netbackup can be 8GB.

hope this helps.

regards

[Pete_From_LTG]

It seems to me like the suggestions are pulled right out of the performance tuning guide - which we are reviewing. These are also solaris/unix/linux based commands (like grep and setting the shared memory). Is there any love for us Windows 2003 x64 guys? We are currently just making up numbers and testing. We can provide any details necessary to get some suggestions - our disk to disk backups were consistently 15000 Kbps/sec and after tweaking for a while now have got it up to a blazing 47 MB/s (set at NUMBER_DATA_BUFFERS_DISK = 64 and SIZE_DATA_BUFFERS_DISK = 262144) but we would like better performance than that!

Message Edited by Pete From LTG on 10-09-2008 10:13 AM

[mbozarth]

Omar you cannot set shared memory minimum and maximum in Windows, that is only for Unix flavors.  You can set buffer size, and number of buffers for each particular component.

[Omar_Villa]

Yeah I think there is something on my brain that when see's the word "win..." it hangs .............................................

[Srikanth_Gubbal]

hi,

this will clear all the confusions

ftp://exftpp.symantec.com/pub/support/products/NetBackup_Enterprise_Server/307083.pdf

NetBackup 6.5 Backup Planning and Performance Tuning Guide (updated October 1, 2008)