[130 _ Storage Service] 002 _ Fujitsu storage system eternus _ advanced copy (advanced copy EC)

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The previous article introduced the advanced copy feature of the storage system and briefly introduced several different methods of advanced copy. They are equivalent copy (EC), one point copy (OPC), snapopc +, and quickopc. This article will further explain equivalent copy (EC ).

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Equivalent copy is the image data that is created or maintained to synchronize with the actual business data. It can maintain real-time synchronization, but if there is a backup operation, the synchronization will be stopped. The EC maintains the consistency between the image data and the business data, at least before the backup operation is performed. Therefore, image data can be used for data backup, such as writing data to a cheap tape storage system. In addition, because only image data is used for backup, the actual business data service will not stop.

To terminate or abort the image synchronization, EC provides us with two methods: complete break and suspend/resume ). The so-called full termination means that the image is completely separated, and the EC will re-create the business data into a new image, and then maintain the image data and business data synchronization from time to time. Temporary suspension means that synchronization can be stopped. That is to say, I can not synchronize data all the time. I can pause synchronization. When I start synchronization again, only the updated parts of the business data will be synchronized, and the service data will not be completely backed up into a new image like the wake-up after the termination.

Of course, the application scenarios of the above two methods are also different. If you think that your business data has not been synchronized, the data will change dramatically, if you think that your business data will not change significantly after the synchronization is terminated, it is undoubtedly the fastest strategy to suspend the synchronization temporarily.

Is the entire EC process, from left to right, according to the chronological order of the implementation of the EC results.

Http://www.fujitsu.com/global/services/computing/storage/eternus/products/diskstorage/feature/strsys-c04.html