Solved

SAN replication using all the bandwidth

Posted on 2009-07-15
6
527 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
ID: 24867955
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
ID: 24868703
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
ID: 24868831
1 gig
0
Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

 
LVL 57

Expert Comment

by:giltjr
ID: 24869325
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
ID: 31603934
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
ID: 24872022
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

U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
Each year, investment in cloud platforms grows more than 20% (https://www.immun.io/hubfs/Immunio_2016/Content/Marketing/Cloud-Security-Report-2016.pdf?submissionGuid=a8d80a00-6fee-4b85-81db-a4e28f681762) as an increasing number of companies begin to…
This tutorial will show how to configure a single USB drive with a separate folder for each day of the week. This will allow each of the backups to be kept separate preventing the previous day’s backup from being overwritten. The USB drive must be s…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

777 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