Backup failed because of slowness

[amit4465]

Backup for a sun solaris server is running dead slow. Please help.

uname -a : SunOS vsoraomd1-l4 5.11 11.2 sun4v sparc sun4v
 

[Marianne]

What is read speed from disk/filesystem on the the client?

Use OS tools such as tar to write filesystem to /dev/null in conjuction with 'time' command or else NBU bpbkar command to write backup to /dev/null.

If read speed from disk is slow, there is very little that can be done from NBU to improve speed.
Speak to server and/or Storage admins.

[amit4465]

I dont have much knowledge about all this, is it possible for you to give me step by step procedure to follow. Thanks.

[mph999]

How fast is the network between the sun server and the media server.

A simple test is to FTP some files (about 100 - 200 MB minimum) from the sun server to the media server - it's only a basic test, but should give some idea of network speed.

To measure disk read speed

Run df -hk - you can then pick a file system, on my server this one has 26GB used, ideal ....

/dev/dsk/c1t2d0s7       30G   2.9G    26G    10%    /diskc1t2d0s7

Then run:

time bpbkar -nocont <filesystem> >/dev/null 2>&1

Eg.

root@womble 1465000000 $ time bpbkar -nocont /diskc1t2d0s7  >/dev/null 2>&1

real    0m44.23s
user    0m0.33s
sys     0m9.56s
 

So in my test, bpbkar read 2.9GB in 44 seconds

Lets call that 3GB to make it easy = 3x 1024MB =  3072MB

3072 /44 = approx 69MB/s  = disk read speed

(the numbers are big enough that if we round it up a bit we'll still get a good enough answer)  If you only backedup say 10MB, then you would hev to be exact on the calculations).