Description

In the FSS environment, due to some llt link network problems, resulting in io performance degradation and instability. we need to use the llttest to produce traffic and to see if there is one node where the llt link is not attached very well.
 
step 1:

Get the LLT numbers using llttest utility from file /etc/llthosts.
 
 step 2:
 
On the remote node, start llttest receiver:
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
 
Immediately, on the sender start llttest sender:
date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N ; date
 
Repeat the test with 64K IO size:
 
Receiver:
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
 
Immediately on the sender:
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N ; date
 
 
 

 
************************************************** ************************************************** **************
 Example:

-bash-4.2$ more etc/llthosts
0 node1
1 node2
2 node3
 
1).
On Node node1
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
 
On node node2
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N 0; date
 
2).
On Node node1
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
 
On node node3
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N 0; date
 
3).
On Node node2
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
On node node1
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N 1; date
 
4).
On Node node2
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
On node node3
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N 1; date
 
5).
On Node node3
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
 
On node node1
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N 2; date
 
6).
On Node node3
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 8192; date
 
On node node2
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 8192 -N 2; date
 
The above steps are to simulate 8k size io, continue to repeat the above steps with 64k below:
 
1).
On Node node1
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
 
On node node2
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N 0; date
 
2).
On Node node1
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
 
On node node3
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N 0; date
 
3).
On Node node2
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
On node node1
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N 1; date
 
4).
On Node node2
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
On node node3
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N 1; date
 
5).
On Node node3
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
 
On node node1
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N 2; date
 
6).
On Node node3
# date; /opt/VRTSllt/llttest -p 30 -R 100000 -s 65536; date
 
On node node2
# date; /opt/VRTSllt/llttest -p 30 -T 100000 -s 65536 -N 2; date