Mirroring is not backup; backup is not archiving

 

Connecting state and local government leaders

Keeping these tiers of storage straight can avert many headaches down the road.

Mirroring is not backup; and backup is not archiving. Keeping these tiers of storage straight can avert many headaches down the road.

Last week, Slashdot posted a cautionary tale about the importance of good backups. Startup company Lagomorphics, which offered a hosted blog space called Journalspace, failed to make regular backups of all of its users' material.

Keep in mind, the company's administrators thought they were making backups. The company mirrored all the users’ data on a second set of drives. The idea was that if one of the drives failed, then a complete copy of all the material would still exist on the mirrored drive.

But what the company did not foresee was a case in which the original database was corrupted, say by an operating system bug or a <a href=http://thewhir.com/web-hosting-news/010509_Blog_Host_Shuts_Down_Following_Data_Loss>malicious administrator</a>, then the material in the other database would also be corrupted, thanks to speedy replication of the originals by the mirroring software.

"There was no hardware failure. Both drives are operating fine. ... The data was simply gone,” a company-posted Web page about the data loss explained.

And that is indeed what happened. Something had wiped out six years of journal entries on the primary database, and a short while later, that empty database was copied over in its entirety to the mirrored site. The company tried the data restoration services of DriveSavers, but to no avail.

For Journalspace, already on shaky ground, this data loss was the final blow. The owners shuttered the service. Users were left to scavenge their old blog entries through the cached copies of Google.

For the rest of us, the lesson is clear: Mirrored copies may be great for load balancing, for application development testing, or even for quick recovery. But don't consider your mirrored copies as the primary backups.

And just as you shouldn't think of mirrored sites as proper backups, nor should you look to backups as an archive, noted EMC director of marketing Sheila Childs, during a presentation on information compliance at the New York Interop conference last fall.

Childs was speaking about the proper ways to retain data for compliance reasons, including e-discovery.

"You should not use backups in any way shape or form for [archiving]. It is the wrong technology," she said. Backups are made to simply preserve working data in case it gets chewed up by misbehaving primary systems. Archiving, on the other hand, is the systemic retention of data that may have be needed later, for legal or historical documentation. Assuming your backups will serve your data retrieval needs during a time of litigation will just lead to lost records and endless hours of futile data searching.

Dixon explained in great detail how the two technologies are different: Backups are in place for a recovery process; Archives are designed for the retrieval of information. Backups house copies; archives hold the originals. Backup is for short term storage; archiving is long term. Backup files are periodically overwritten; archives are retained for long periods of time. Backups tends to be done with proprietary technology; archive technology tends to use more open standards, so material can better be retrieved years or decades from now.

"Backup technologies are meant to be used for recovery. They are meant to be recycled. The mindset of archiving is to take that material out of your system and put it some place and leaving it," she said.

Archiving can help with backups. By moving some of the older material off to archives, you can free some of the backup space and cut down backup times.

"Archiving is a technology that is complementary to backup ... but it is very very different," she said.

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.