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Linux SAN media server performances issue --- Low speed

rajeshthink
Level 4

Greeting to all ...

I have two SAN media server which we recently build , We did certain test and from SAN media server A we are getting speed of 70 -100 MB/s , where as from SAN media server B we get max thoughput of 20 -30 MB/s .

-----Zoning are perfect

 

 

Cheer,

Rajesh Kumar

1 ACCEPTED SOLUTION

Accepted Solutions

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified

Start with troubleshooting outside of NBU. 

1. Test read speed from disk using bpbkar test:
Increase logging level to 1
Create /usr/openv/netbackup/logs/bpbkar folder
Run: /usr/openv/netbackup/bin/bpbkar -nocont -dt 0 -nofileinfo -nokeepalives <filesystem> > /dev/null  
Check results in bpbkar log

If read performannce is good, test write speed to tape:

2. Load a scratch/blank tape in a drive.
Use tar or cpio to write backup to drive.
Note time taken to write backup.

If both methods above shows good performance, then tune NBU buffers.
Create these 2 files: 

/usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS 
add a value of 
262144

/usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS 
add a value of 32 (can be more if server resources are sufficient)

Ensure bptm log folder exists to verify effect of buffer settings.
 

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4 REPLIES 4

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified

Start with troubleshooting outside of NBU. 

1. Test read speed from disk using bpbkar test:
Increase logging level to 1
Create /usr/openv/netbackup/logs/bpbkar folder
Run: /usr/openv/netbackup/bin/bpbkar -nocont -dt 0 -nofileinfo -nokeepalives <filesystem> > /dev/null  
Check results in bpbkar log

If read performannce is good, test write speed to tape:

2. Load a scratch/blank tape in a drive.
Use tar or cpio to write backup to drive.
Note time taken to write backup.

If both methods above shows good performance, then tune NBU buffers.
Create these 2 files: 

/usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS 
add a value of 
262144

/usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS 
add a value of 32 (can be more if server resources are sufficient)

Ensure bptm log folder exists to verify effect of buffer settings.
 

Yasuhisa_Ishika
Level 6
Partner Accredited Certified

GEN_DATA directive is pretty nice to isolate performance issue. You can measure performance between media server and storage unit in NetBackup. No need to mount tape manually.

http://www.symantec.com/docs/TECH75213

rajeshthink
Level 4

I Just change the Data_buffer_size from 128 to 256 and Now i see a fair speed its writing the data.

Hope this resolve the issue , Also the backup use to take 4 days to complete Now its taking just 2 days..

so think the next step would be changing it o 512.

 

any suggestion are Appriciated .

 

cheer,

Rajesh Kumar

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified