Part 2 – EMC VPLEX Experiences

Hi

Thanks, for coming back, or reading on from my previous post on EMC’s VPLEX kit and my experiences.

The first thing I was going to cover in this post is the most common commands that I’ve been using and what they are for. This is as much for my ease of reference as it is to touch on them for anyone else reading J

To begin with, there are two main places where you use the CLI

The Clusters management Server and the VPLEXcli

To logon to the Cluster Management interface you open a SSH connection using your preferred SSH client

  • IP address of the Cluster Management Ethernet interface
  • Port 22
  • SSH Protocol 2
  • Scrollback lines to 20000

 

When you you get to the logon interface you need to logon as the appropriate account, during the implementation phase this is probably going to be the service account. As always, please be smart about security and get this password changed early and don’t leave the default passwords on the default accounts

When you are logged in you will come to the following interface:

service@ManagementServer:~>

 

The second place you perform most of your CLI work is the VPLEXcli, you need to logon to the Management Server first and then enter the VPLEXcli using the command VPLEXcli (wow, who would have guessed it would be that easy!)

service@ManagementServer:~> vplexcli

 

Several messages are displayed, and a username prompt appears:

Trying 127.0.0.1...

Connected to localhost.

Escape character is '^]'.

Enter User Name:

 

Again, you will need to authenticate with the appropriate UN and PW. Probably still the Service account you used to logon to the Management Server. When logged on successfully you’ll see the following:

creating logfile:/var/log/VPlex/cli/session. 

log_service_localhost_T28921_20101020175912

 

VPlexcli:/>

 

I found it highly useful to run up two sessions of putty, and logon with both, one that stay’s logged onto just the cluster management server and the other logged into the VPLEXcli. This allows you to quickly flick back and forth.

 

Commands

 

 

You can confirm that the Product Version of what’s running matches the required version in the VPLEX release notes and your expectations.

version -a

 

 

Verify the VPLEX directors

 

From the VPlexcli prompt, type the following command:

ll /engines/**/directors

Verify that the output lists all directors in the cluster, and that all directors show the following:

  • Commissioned status: true
  • Operational status: ok
  • Communication status: ok

Output example in a dual-engine cluster:


 
 

 

Verify storage volume availability

From the VPlexcli prompt, type the following commands to rediscover the back-end storage:

cd/clusters/cluster-1/storage-elements/storage-arrays/EMC-*

array re-discover <array_name>

Type the following command to verify availability of the provisioned storage:

storage-volume summary

 
 


 
 

Resume-at-loser

This is probably one of the most important commands to know, after you’ve had an outage of some type and you need to get your data re-sync’d

 

During an inter-cluster link failure, an you or your client can allow I/O to resume at one of the two clusters the “winning” cluster.

I/O remains suspended on the “losing” cluster. When the inter-cluster link heals, the winning and losing clusters re-connect, and the losing cluster discovers that the winning cluster has resumed I/O without it. Unless explicitly configured otherwise (using the auto-resume-at-loser property), I/O remains suspended on the losing cluster. This prevents applications at the losing cluster from experiencing a spontaneous data change. The delay allows the administrator to shut down applications and get into a clean state. After stopping the applications, the administrator can use this command to resynchronize the data image on the losing cluster with the data image on the winning cluster, Resume servicing I/O operations. The administrator may then safely restart the applications at the losing cluster.

 

Without the ‘–force’ option, this command asks for confirmation to proceed, since its accidental use while applications are still running at the losing cluster could cause

applications to misbehave.

 

 

Cd /clusters/cluster-n/consistency-groups/group-name/resume-at-loser
			

 

 

One of the important things to check is the Rx and Tx power of your FC modules, the following command allows you to bring this up and look for discrepancies or things that are out of the ordinary.

Ccd /engines/engine-1-1/directors/director-1-1-A/hardware/sfps/

 

 

 

Next up is some information around VPLEX and storage, and then VPLEX and VMWare Vsphere.

 

 


2 responses to “Part 2 – EMC VPLEX Experiences

  • m_b

    Very informative. Keep posting more of VPLEX stuff .. esp stuff like this that’s not there in the guides .
    thanks.

  • djw

    Hi Dallas. Only just found these article. Hope you’re still planning to continue them as this is very timely from our perspective. Currently having VPLEX configured and very interested to hear your vsphere/vplex experiences and compare them to what we’ve got VPLEX for once its fully configured

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