Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

News

4/1/2011
10:20 AM
George Crump
George Crump
Commentary
50%
50%

Dealing With Peak Storage I/O

A peak in storage I/O occurs when an application suddenly has a spike of I/O requests to and from the storage device. Prior to virtualization we sized servers that applications ran on and the storage infrastructure that those servers used specifically for those peak times. This means that most of the time those servers sat idle. Thanks to virtualization, we can't size hosts to handle the load if all its VMs peaked.

A peak in storage I/O occurs when an application suddenly has a spike of I/O requests to and from the storage device. Prior to virtualization we sized servers that applications ran on and the storage infrastructure that those servers used specifically for those peak times. This means that most of the time those servers sat idle. Thanks to virtualization, we can't size hosts to handle the load if all its VMs peaked.Performance tuning and dealing with peaks in storage I/O demands has now become a top concern for storage administrators. In fact in a recent survey conducted by Storage Switzerland over 50% of the respondents listed performance tuning and troubleshooting as the biggest storage challenge caused by server virtualization. It is also the primary reason often given for virtualization stall because the organization struggles with how to maintain performance service levels with the business units.

Peak storage I/O can come from an increase in batch processing like at the end of a quarter or it can come from a sudden spike in the number of online users. The impact in a virtual environment may be that the application may never be able to service the peak load because the resources are not there. If it does it may mean that other virtual machines on the physical host become starved for resources and their performance suffers severely. That's the challenge with virtualization, everything impacts everything. In either case the result is not good and applications become so slow that they actually feel like they have stopped to the user. This is just as bad as an application crash so avoiding that situation is critical.

One solution is to build, as we discussed in our recent webinar, "Stopping The Storage Roadblock To Server Virtualization", a much faster storage infrastructure. Storage networks built on 10GbE are affordable and deliver a significant performance boost to the environment especially those that do not have to deal with IP overhead. The other option is to understand your environment and make better use of the current resources. The reality is you will probably need to build both a faster network and now how to fine tune that network.

Monitoring the virtual environment requires real-time or near real-time information to be able to assess how resources like storage I/O are being consumed. It also means seeing that consumption at both the virtual machine level and the physical host level. You need to know which virtual machines are chewing up resources and you need to know which physical hosts have resources available if you decide to move virtual machines around to balance out the load.

When a peak storage I/O load occurs, if you can identify the virtual machine causing the problem via a monitoring tool you have several choices. One choice is to move the other VMs on the physical host to other physical hosts. This frees up most of the resources of the host for that particular task. You could also move the VM causing the I/O peak to a host that has plenty of free resources. In extreme situations you may want to actually move the peak VM out of the virtual environment. As we discussed in our article "Virtual To Physical Machine Conversion To Mitigate Risk" some migration tools are enabling those capabilities and it is a good one to have on your IT utility belt.

The good news is that server virtualization provides the flexibility to deal with peak storage I/O loads. The critical component however is knowing which of those options is going to best help you get through the peak load. The only way to know that is through the use of a monitoring tool that can give you the analytics to make the right decision.

Track us on Twitter: http://twitter.com/storageswiss

Subscribe to our RSS feed.

George Crump is lead analyst of Storage Switzerland, an IT analyst firm focused on the storage and virtualization segments. Find Storage Switzerland's disclosure statement here.

 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 7/13/2020
Omdia Research Launches Page on Dark Reading
Tim Wilson, Editor in Chief, Dark Reading 7/9/2020
Mobile App Fraud Jumped in Q1 as Attackers Pivot from Browsers
Jai Vijayan, Contributing Writer,  7/10/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Special Report: Computing's New Normal, a Dark Reading Perspective
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
The Threat from the Internetand What Your Organization Can Do About It
The Threat from the Internetand What Your Organization Can Do About It
This report describes some of the latest attacks and threats emanating from the Internet, as well as advice and tips on how your organization can mitigate those threats before they affect your business. Download it today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-14174
PUBLISHED: 2020-07-13
Affected versions of Atlassian Jira Server and Data Center allow remote attackers to view titles of a private project via an Insecure Direct Object References (IDOR) vulnerability in the Administration Permission Helper. The affected versions are before version 7.13.6, from version 8.0.0 before 8.5....
CVE-2019-20901
PUBLISHED: 2020-07-13
The login.jsp resource in Jira before version 8.5.2, and from version 8.6.0 before version 8.6.1 allows remote attackers to redirect users to a different website which they may use as part of performing a phishing attack via an open redirect in the os_destination parameter.
CVE-2019-20898
PUBLISHED: 2020-07-13
Affected versions of Atlassian Jira Server and Data Center allow remote attackers to access sensitive information without being authenticated in the Global permissions screen. The affected versions are before version 8.8.0.
CVE-2019-20899
PUBLISHED: 2020-07-13
The Gadget API in Atlassian Jira Server and Data Center in affected versions allows remote attackers to make Jira unresponsive via repeated requests to a certain endpoint in the Gadget API. The affected versions are before version 8.5.4, and from version 8.6.0 before 8.6.1.
CVE-2019-20900
PUBLISHED: 2020-07-13
Affected versions of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the Add Field module. The affected versions are before version 8.7.0.