Recovering a file system

Replication and Disaster Recovery Administration Guide for Hitachi NAS Platform

Version
15.1.x
Audience
anonymous
Part Number
MK-92HNAS009-29
To recover a file system from a snapshot:
  1. Navigate to Data Protection > File System Versions to display the File System Versions page.


    The following table describes the fields in this page:

    Field/Item Description
    File System Details This section displays the name of the EVS hosting the file system, and the currently selected file system that can be recovered from the snapshots listed in the Versions section.
    EVS/File System Displays the name of the currently selected EVS and file system. Click change to select a different file system.
    Status Displays the current mount status of the file system. The file system status may be Syslocked, Checking, Unmounted, Mounted, Mounted as read only or Mounted as a replication target.
    Object Replication Details For Latest Version If the file system is a replication target, this section displays the status of the most recent replication and information about the replication source. If the currently selected file system is not a replication target, or the replication information cannot be retrieved (if the source server is not known to the replication process), the Source File System, Source Server, and Source File System Status fields are not displayed.
    Status If the currently selected file system is a replication target, this field displays a status indicator and a message about the most recent replication. If the file system is not a replication target, the status indicator is greyed out and the message reads "Latest version is not an object replication target".

    The status indicator is green if the most recent object replication completed successfully. If the first full replication is currently running, this status indicator is grey.

    If the currently selected file system is not involved in a replication policy (neither the source or the target), then the message reads "No status found".

    If a replication associated with this file system has not yet run, the light is grayed out, and the message reads, "No status found".

    Source File System If the currently selected file system is a replication target, this field displays the name of the source EVS and file system.

    If the currently selected file system is not a replication target, this field is not displayed.

    Source Server If the currently selected file system is a replication target, this field displays the name of the server hosting the EVS/replication source file system.

    If the currently selected file system is not a replication target, this field is not displayed.

    Source File System Status If the currently selected file system is a replication target, this field displays the current mount status of the replication source file system. The file system status may be Not mounted, Mounted, Mounted as read-only, Syslocked, or Checking.

    If the currently selected file system is not a replication target, this field is not displayed.

    Versions This section lists versions of this file system that are in available snapshots, and identifies the snapshot copied to the replication target and the replication source snapshot.
    Time of Version The date and time the object replication policy last ran. "Time" refers to when the snapshot was taken.
    Version Identifies the specific snapshot copied to the replication target.
    Replicated From Snapshot Identifies the replication's source snapshot.
    Recover File System To Version Opens the File System Recovery Selection page, on which you choose the type of file system recovery you want.
    Recover Multiple File Systems To Version Opens the Recover File Systems page, on which you choose options for recovering multiple file systems.
    File System Recovery Reports Opens the file system File System Reports page.
    Object Replication Policies & Schedules Opens the main Object Replication page.
  2. Click Recover File System to Version.
  3. Use this page to begin the recovery process and either:
    • Promote the file system to a normal file system (and optionally, mount it as read-write or read-only).
    • Demote the file system to an object replication target (and mount it as an object replication target).

    In order to promote or demote a file system, the process rolls back the file system to the last successful replicated snapshot. You must check the available snapshots so that you can choose the most recent (in order to minimise data loss due to promoting a previous version of the file system). Using your browser, go back to the File System Versions page and note the time and version of the snapshots, so you can choose the most recent successful replication snapshot.

    In a disaster recovery scenario, your primary system will probably be unavailable, so you must access the file system version using the File System Versions page of the backup system at the recovery site. Note the time of the replication snapshot and the versions of the source and target. You will use the latest version when promoting the file system to a normal file system.