Solved

SAN replication using all the bandwidth

Posted on 2009-07-15
6
525 Views
Last Modified: 2013-11-14
We have recently been having problems with bandwidth on a 1GB lan extension link between our office  and data centre.
The bandwidth used to average at about 2% - 10% but now averages at 35%+ with periodic bursts of over 100%.
 This is due to a new SAN that has been installed by an external company. They say that the SAN is permanently replicating and it is normal to use that amount of bandwidth.
 It is set to use up to 75% of available  bandwidth and that 35% is quite low.
Can someone confirm this is correct or even suggest a  solution other than get another link?
The links at the sites are 1gb into MDS switches.
0
Comment
Question by:andrewsmith950
  • 3
  • 2
6 Comments
 
LVL 55

Accepted Solution

by:
andyalder earned 175 total points
Comment Utility
Site to site SAN replication can take a lot of bandwidth, for example if you use VMware and replicate the actual VMs and one is paging all that pagefile activity is unnecessarily replicated to the other site.
0
 
LVL 57

Assisted Solution

by:giltjr
giltjr earned 175 total points
Comment Utility
The amount of bandwidth should be based on how much data you are writting to your SAN.

If  you are writing/updating a lot of data, then you will use a lot of bandwidth.

Based on your numbers (1 Gbps link with 35% utilization) that means you are doing about 300 Mbps which is about 37 MB per second.

If you were averaging 2-10% that means that you may have been doing 1-2MB per second before so the SAN replication added 35 MB per second.  What is your I/O rate to the local SAN.
0
 

Author Comment

by:andrewsmith950
Comment Utility
1 gig
0
Why You Should Analyze Threat Actor TTPs

After years of analyzing threat actor behavior, it’s become clear that at any given time there are specific tactics, techniques, and procedures (TTPs) that are particularly prevalent. By analyzing and understanding these TTPs, you can dramatically enhance your security program.

 
LVL 57

Expert Comment

by:giltjr
Comment Utility
Are you saying you are updating 1 GB ps of data on your local SAN?

Or are you saying that the available bandwidth to your local SAN is only 1 Gbps?

What you need to look at is how much data per second do you update on your local SAN and then what you are replicating.  

As andyalder pointed out, there are somethings you should not be replicating, but you need to figure that out.

0
 

Author Closing Comment

by:andrewsmith950
Comment Utility
Thanks . I don't know a lot about SANs so was just confirming what I was being told. Many thanks
0
 
LVL 57

Expert Comment

by:giltjr
Comment Utility
Thanks.  

Just a little F.Y.I.  SAN are really nothing more than disk drives attached via a network.  Instead of Ethernet and IP as their lower level networking protocols they typically use Fiber Channel and have their own private physical network.  They also typically have much more bandwidth than LAN, which is what you typiclaly think of when here networking.
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

Even if you have implemented a Mobile Device Management solution company wide, it is a good idea to make sure you are taking into account all of the major risks to your electronic protected health information (ePHI).
Don’t let your business fall victim to the coming apocalypse – use our Survival Guide for the Fax Apocalypse to identify the risks and signs of zombie fax activities at your business.
This tutorial will walk an individual through the process of configuring basic necessities in order to use the 2010 version of Data Protection Manager. These include storage, agents, and protection jobs. Launch Data Protection Manager from the deskt…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

772 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

11 Experts available now in Live!

Get 1:1 Help Now