Dell PowerStore 1200T EMC PowerStore Protecting Your Data - Page 6

1 Introduction This chapter contains the following information: Topics: • Data protection • Snapshots • Replication • Protection policies • Metro protection Data protection PowerStore provides both local and remote data protection. Using the PowerStore Manager, you can protect your data locally by creating snapshots (point-in-time copies) of volumes, volume groups, virtual machines, or file systems. You can also apply remote protection by replicating your data to a remote system, or mirroring the data using metro volumes for redundancy in the event of a disaster. PowerStore enables you to create custom protection policies, which are sets of rules for snapshot creation, replication, or both, and assign them to volumes, file systems, and NAS servers. Protection policies apply the defined rules on the storage resource, providing it with local and/or remote protection. NOTE: Protection policies that include a replication rule cannot be assigned to metro volumes. See Using protection policies with metro. NOTE: As of version 3.x, protection policies cannot be applied to virtual volumes based virtual machines. See Virtual volumes replication. Snapshots Snapshots are read-only, point-in-time copies of data of a volume, volume group, virtual machine, or file system. Creating a snapshot saves the state of the storage resource at that particular point-in-time. Using snapshots, you can easily protect your data locally and restore a storage resource to a previous state. You can manually create snapshots at any time. It is also possible to configure snapshot rules as part of a protection policy and assign them to the relevant storage resources. The system automatically creates snapshots of the relevant resource according to the schedule specified in the protection policy. If data corruption occurs or data is accidentally deleted, you can recover the data from the snapshots or restore the volume or volume group to the point in time when the snapshot was created. For file systems, you can create two access types of read-only file snapshot: protocol and .snapshot. The default access type is protocol, which can be exported as an SMB share, NFS export, or both. You can share and mount the snapshot on a client like any other file system. For .snapshot access types, you can access the files within the snapshot from the production file system in the.snapshot subdirectory of each directory. You can also create write-order consistent and application consistent snapshots of volumes: ● Write-order consistent snapshots - PowerStore holds all writes on the volume group members to provide a uniform point-intime copy, and therefore ensure consistent protection across all member volumes. You can generate write-order consistent snapshots from the PowerStore Manager. ● Application consistent snapshots - You can create application consistent snapshots of a volume or a volume group using AppSync. When creating an application consistent snapshot, all incoming I/O for a given application is quiesced while the snapshot is created. To verify whether a snapshot is write-order consistent or application consistent, look at the Write-Order Consistent and Application Consistent columns in the snapshot tables for a volume or volume group in PowerStore Manager. 6 Introduction