News
10/21/2009
03:43 PM
George Crump
George Crump
Commentary
50%
50%

Understanding Hard Drive Performance

In the last performance entries we discussed understanding storage bandwidth and understanding storage controllers. Next up is to understand the performance characteristics of the hard drive itself and how the mechanical hard drive can be the performance bottleneck.

In the last performance entries we discussed understanding storage bandwidth and understanding storage controllers. Next up is to understand the performance characteristics of the hard drive itself and how the mechanical hard drive can be the performance bottleneck.The big problem with hard drives is that they are stuck from a performance perspective. While everything else has increased in speed over the past few years, the fastest hard drives have been locked in at 15K RPM. What has kept mechanical drives viable in performance concerned data centers is the ability to group multiple drives together in an array group. Each drive in the array can respond to storage I/O requests. As long as you have enough requests, also known as queue depth, every time you add a drive to an array group performance improves.

The downside to large drive count array groups is that you often run into wasted capacity because so many drives are added to hit the performance requirement that the application can't use all the capacity that came along with the drive. Companies like 3PAR, Xiotech and Isilon get around this by performing fine grain virtualization, meaning they can stripe all the data from all the attached servers across all or most of the available drives in the storage system. This technique, known as wide striping, for many organizations strikes a balance between high performance and efficient capacity utilization.

At some point however you have a situation where you have added so many drives that it is not cost effective to do so or you run out of storage I/O requests and you have a response time or latency issue. The only step left is to speed up the drive itself.

Where are 20K RPM drives? While 20K RPM hard drives have been researched by various vendors, they have not been found to be viable for the market. There are problems with the heat, vibration and reliability issues with these faster drives. Cost is also an issue with 20K RPM hard drives. In fact they may be more expensive than an equivalent capacity Solid State Disk (SSD). For reasons we state in "SSD's are cost effective NOW", the downward price trend on SSDs seems to have eliminated the development of the 20K RPM drive market. With SSD you get better performance with none of the heat and vibration issues that were set to plague 20K drives. Finally SSDs, especially enterprise class SSD using SLC Flash, have proven to be as reliable as mechanical drives.

For many environments drive performance is not an issue and a simple array group of 10K or even 7.5K RPM drives provides all the performance their applications need. As performance becomes an issue, and storage controller and bandwidth issues are eliminated, then adding drive count is the next logical step, especially if you can leverage technologies like fine grain virtualization. Eventually the final stop is SSD.

Even in SSD their is likely to be tiers of service and you will want to use different SSD technologies for different SSD classes.

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.

Comment  | 
Print  | 
More Insights
Comments
Oldest First  |  Newest First  |  Threaded View
Register for Dark Reading Newsletters
Dark Reading Live EVENTS
INsecurity - For the Defenders of Enterprise Security
A Dark Reading Conference
While red team conferences focus primarily on new vulnerabilities and security researchers, INsecurity puts security execution, protection, and operations center stage. The primary speakers will be CISOs and leaders in security defense; the blue team will be the focus.
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: No, no, no! Have a Unix CRON do the pop-up reminders!
Current Issue
Security Vulnerabilities: The Next Wave
Just when you thought it was safe, researchers have unveiled a new round of IT security flaws. Is your enterprise ready?
Flash Poll
The Impact of a Security Breach 2017
The Impact of a Security Breach 2017
Despite the escalation of cybersecurity staffing and technology, enterprises continue to suffer data breaches and compromises at an alarming rate. How do these breaches occur? How are enterprises responding, and what is the impact of these compromises on the business? This report offers new data on the frequency of data breaches, the losses they cause, and the steps that organizations are taking to prevent them in the future.
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2017-0290
Published: 2017-05-09
NScript in mpengine in Microsoft Malware Protection Engine with Engine Version before 1.1.13704.0, as used in Windows Defender and other products, allows remote attackers to execute arbitrary code or cause a denial of service (type confusion and application crash) via crafted JavaScript code within ...

CVE-2016-10369
Published: 2017-05-08
unixsocket.c in lxterminal through 0.3.0 insecurely uses /tmp for a socket file, allowing a local user to cause a denial of service (preventing terminal launch), or possibly have other impact (bypassing terminal access control).

CVE-2016-8202
Published: 2017-05-08
A privilege escalation vulnerability in Brocade Fibre Channel SAN products running Brocade Fabric OS (FOS) releases earlier than v7.4.1d and v8.0.1b could allow an authenticated attacker to elevate the privileges of user accounts accessing the system via command line interface. With affected version...

CVE-2016-8209
Published: 2017-05-08
Improper checks for unusual or exceptional conditions in Brocade NetIron 05.8.00 and later releases up to and including 06.1.00, when the Management Module is continuously scanned on port 22, may allow attackers to cause a denial of service (crash and reload) of the management module.

CVE-2017-0890
Published: 2017-05-08
Nextcloud Server before 11.0.3 is vulnerable to an inadequate escaping leading to a XSS vulnerability in the search module. To be exploitable a user has to write or paste malicious content into the search dialogue.