Recovering A Repository; Managing Security - Dell DL4000 User Manual

The Volumes remount.
Resolving foreign volumes
If a provisioned MD1200 is powered off or disconnected and then later powered back on, an event
appears on the Core Console reporting that the MD1200 is connected. However, no task appears on the
Appliance tab Tasks screen that permits you to recover it. The Enclosures screen reports the MD1200 as
being in a foreign state and the repositories on the foreign virtual disks as off-line.
To resolve foreign volumes:
1. From the Core Console, select the Appliance tab, and then click Remount Volumes.
The volumes remount.
2. Select the Configuration tab, and then click Repositories.
3. Expand the repository with the red status indicator by clicking > next to Status.
4. To verify the repository integrity, under Actions, click Check.

Recovering a repository

When the appliance fails to import a repository, it reports the failure in the Tasks screen with the task
status indicated by a red circle, and the status description reporting Error, Completed — Exception. To
view the error details from the Tasks screen, expand the task details by clicking > next to the Status
column. Status Details reports that the recovery task status is exception, and the Error Message column
provides additional details about the error condition.
To recover a repository from a failed import state:
1. Navigate to the Core Console.
The Repositories screen displays the failed repository with a red status indicator.
2. Click Configuration → Repositories.
3. Expand the failed repository by clicking > next to Status.
4. From the Actions section, click Check, and then click Yes to confirm that you want to run the check.
The appliance recovers the repository.

Managing security

The Core can encrypt protected machine snapshot data within the repository. Instead of encrypting the
entire repository, you can specify an encryption key during the protection of a machine in a repository
which lets the keys be reused for different protected machines. Encryption does not affect performance,
as each active encryption key creates an encryption domain, thus letting a single core support
multitenancy by hosting multiple encryption domains. In a multi-tenant environment, data is partitioned
and deduplicated within the encryption domains. Because you manage the encryption keys, loss of the
volume cannot leak the keys. Key security concepts and considerations include:
• Encryption is performed using 256 bit AES in Cipher Block Chaining (CBC) mode that is compliant
with SHA-3.
• Deduplication operates within an encryption domain to ensure privacy.
• Encryption is performed without impact on performance.
• You can add, remove, import, export, modify, and delete encryption keys that are configured on the
Core.
• There is no limit to the number of encryption keys you can create on the Core.
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