You can configure and monitor an external storage FTP server. Only superusers can configure the external storage server. Using external storage, you can store and retrieve snapshots and templates. The external storage is accessible only through FTP. The FTP protocol supports passive or active modes automatically. No other protocol is supported for the interaction between Multi-Grid Master and external storage server. Multi-Grid Manager supports Apache FTP server and Windows 2008 R2 FTP server. Only the Grid Master interacts with the external storage server.

Note: Make sure that the data in the external storage system is secure. The Multi-Grid Manager cannot protect and secure data in the external storage server. Also, you can configure only one external storage server for one Multi-Grid Manager.

External Storage Requirements

A home directory should exist in the external storage server and the FTP user with read/ write permission should be able to perform the following in the home directory:

• create, delete, and change directory
• list files and directory
• create, rename, and delete a file

File Operations in External Storage

Multi-Grid Master automatically uploads a file when snapshot is captured for attach or detach operation. The following operations on the external storage is logged on the Multi-Grid Master:

• storing a file (operation, filename, temporary filename used during upload)
• deleting a file (operation, filename)

Backing Up Data

Multi-Grid Manager backups do not include the content of the external storage. You have to set up a backup mechanism for the backup of the external storage server. Infoblox recommends to take external storage backup along with the Multi-Grid Manager backup.
The external storage backup should include:

• all the files in the infoblox/MGM.[uuid]/ directory, where uuid is the 16 character long hexadecimal string, which is unique and tied to the Multi-Grid Manager.
• file path relative to the home directory with infoblox/MGM.[uuid] prefix.
• permissions and ownership of the files.

Best practice to restore a backup data is to first restore the external storage backup and then restore a Multi-Grid Manager backup. Note that the Multi-Grid Manager restore operation points to the external storage specified in the Multi-Grid Manager backup, which should match with the external storage being used to restore the external storage content. When you restore a backup, it restores all the files at the root of the home directory on the external storage. Permissions and ownership of the files are also restored as defined in the backup.

File Hierarchy

All directories and files are stored in the directory: infoblox/MGM.[uuid]/ where [uuid] is the unique identifier of the Multi-Grid Manager. This prevents multiple Multi-Grid Managers configured to use the same storage and home directory to collide. The directory is relative to the home directory configured through FTP to connect to the external storage.

Note: Tampering any file in the home directory can result in unavailability of the tampered files in the Multi-Grid Manager that uses this directory.

External Storage Space Limit

You can define a maximum space limit on the external storage. It defines the maximum space available to Multi-Grid Manager to store files on the storage. The maximum space limit is defined as a number of bytes which is compared against the sum of all the files stored under the infoblox/MGM.[uuid]/ directory.
You can set the maximum space limit to a larger value, in which case Multi-Grid Manager is limited to the total space of the external storage. Multi-Grid Manager does not delete any data even if the size of the space used on the external storage is above the maximum space limit. In addition, it does not enforce a maximum file size, but is subjected to the maximum file size supported by the file system used by the external storage.

Monitoring External Storage Server

You can monitor the connectivity and space usage of the external storage server. The status can be one of the following:

About Archive Files

The snapshots and templates are stored in the same file format. A snapshot or a template is stored in a single file with the following characteristics:

• archive file is a tar file
• archive is not encrypted
• archive contains the following files:
  • descriptor file and descriptor signature file
  • audit log archive file and audit log signature file
  • Grid backup file and Grid backup signature file
  • Optionally, an archive file can also have the following information based on the settings in the Snapshot tab of the Grid Editor wizard:
    • file distribution data. If file distribution data is available, then it is stored in the Grid backup file.
    • lease history archive file and lease history signature file.
    • syslog archive per appliance and each syslog archive followed by its signature file. Grids that are offline will have 0 byte file.

File Formats in Archives

• Audit Log Archive - Stored as audit_log.tar.gz. This archive has a gzip of the current and rolled Grid audit logs.
• Grid Backup - Stored as backup.bak.gz. This archive has a gzip of the original Grid backup. The original Grid backup follows the same format as regular NIOS backup obtained from the Grid. It contains the file distribution content and bloxtools data if snapshot is configured to include it.
• Lease History Archive - Stored as lease_history.gz. This archive has a gzip of the Grid CSV export of the lease history data.

• Syslog Archive - Stored as syslog-[member]-[role].tgz, where [member] is the FQDN of the member from which the syslog is extracted, [role] is either active or passive and allows to find out from what appliance the syslog is extracted in case the member is an HA pair. When the member is a single appliance, the [role] is always active. This is a tar gzip of the current and rolled syslog files of a Grid. if a Grid goes offline, the tar file contain only a single empty file named offline.

• Signature Files - Multi-Grid Manager uses signature files to verify the integrity of the data.

Locating Snapshots and Templates

All snapshots and templates are stored on the external storage FTP server.

• Templates are stored in the templates subdirectoryof the directory infoblox/MGM.[uuid]/
• The snapshots are organized for a Grid and are stored in the subdirectory infoblox/MGM.[uuid]/
  where, <uuid>
  • uuid is a unique 16 character long hexadecimal string tied to the Grid.
  • For each subdirectory, an empty companion file exists in infoblox/MGM.[uuid]/, defined as follows:
  • <uuid>.<Grid>
    where, uuid is a unique 16 character long hexadecimal string tied to the Grid as known by Multi-Grid Manager and <Grid> is the Grid name as known by Multi-Grid Manager.
  • any non ACII or printable character or space in the Grid name is replaced with an underscore.

Note: The Grid name may not always be consistent with the Grid name on the Multi-Grid Manager. It updates Grid name once in every hour.

Naming Format of a Snapshot File

The snapshot file name will be in the format <uuid><type><Grid>-<date>.tar where,

• uuid - unique ID to identify a Grid.
• type - attach (for attach snapshots), detach (for detach snapshots) and manual (for manual snapshots).
• Grid - Grid name at the time of capturing a snapshot. Any non ACII or printable character are replaced with an underscore. Spaces are replaced with an underscore. This value is constant and does not change when the Grid name is changed, either in Master Grid or on the Grid.
• Date - Timestamp of the snapshot operation in the YYYYMMDD-HHMMSS. Timestamp is UTC and it is the time at which the Multi-Grid Manager started the snapshot operation.

Note: The tar file becomes unusable if it is changed.

Configuring External Storage
Only superusers are able to configure an external storage server. All the configuration changes made to the external storage are logged in the audit log of the Multi-Grid Manager. You can modify the configuration only when the external storage server is disabled. The configured password is masked in the audit log entry.
The snapshots are not captured when:

• the external storage server is full.
• there is no connectivity between external storage server and Multi-Grid Manager.

You can view how much space is being used and how much free space you have on the external storage server through the Grid Connection Status widget on your Dashboard. For more information, see /wiki/spaces/mgmadminguide/pages/911180386. You can also view the space details using the Detailed Status icon. The external server space usage is not updated in the real time. Some of the operations might fail if the external storage space is full and Multi-Grid Manager might not have updated it. When the external storage server space reaches the maximum value, the snapshots are not captured and the connection status is updated accordingly. The Master Grid logs an entry to indicate that the snapshots are not captured because there was no space in the external storage server.
You can allocate space, define the maximum number of snapshots to be captured for the attach and detach operations, test the storage connection and disable the external storage server using the External Storage Editor wizard:
To configure an external storage server:

1. Log in to the Multi-Grid Master.
2. From the Master Grid tab, select the Members tab.
3. On the vertical toolbar, click External Storage.
4. In the Server Address text box, enter the FTP server IP address. This can be IPv4 or IPv6 address or FQDN.
5. In the Server Port text box, enter the port number of the FTP server.
6. In the Server Login text box, enter the login user name.
7. In the Server Password text box, enter the server password.
8. Do the following to define storage space:
   • In the Maximum Available Storage Space text box, enter the maximum available storage space. Select the unit of the storage space. You can select GB gigabyte or TB terabyte.
   • In the Maximum Snapshots per Grid text box, enter the maximum number of snapshots you want to store in the external space for a Grid. When you decrease the set value, the Multi-Grid Manager automatically deletes the excess snapshots. For example: If you specify 10, the system will capture 10 snapshots. After this number, Multi-Grid Manager deletes the first record and saves the 11th snapshot.
   • In the Maximum Detach Snapshots per Grid text box, enter the maximum number of detach snapshots you want to store in the external space for a grid. For example: If you specify 10, the system will capture 10 snapshots. After this number, Multi-Grid Manager deletes the first record and saves the 11th snapshot.
9. Optionally, you can click Test Storage Connection to test the server connection.
10. Click Save to save the configuration.

Testing External Storage Connection

It is a good practice to test the external storage server connection to ensure that the external storage is initialized. Infoblox recommends you to test whenever you modify the external storage configuration. The Grid Master logs all the test results in the syslog and also captures error in case of test failure.

1. Log in to the Multi-Grid Master.
2. From the Master Grid tab, select the Members tab
3. From the External Storage drop down list, click Test.
4. In the External Storage Test, do the following:
   • Server Address: Enter the IP address of the server.
   • In the Server Port text box, enter the port number of the server.
   • In the Server Login text box, enter the login user name.
   • In the Server Password text box, enter the server password.
5. Click Test to check the connection of the server. A message is displayed about the availability of the server.

You can also test the availability while configuring the server in the External Storage Editor using the Test Storage Connection option.

Disabling External Storage Sever

You can disable the connection between the external storage server and the Master Grid at any point of time. The snapshot is not captured when you disable the external storage server. An error message is displayed to indicate that the external storage server is not enabled. The Master Grid logs an entry to indicate that the snapshot is not captured because the external storage server was disabled. The snapshot is captured only when the external storage server is enabled and connection between the server and the Multi-Grid Manager is restored.
To disable the external storage server:

1. Log in to the Multi-Grid Master.
2. From the Master Grid tab, select the Members tab, and then click External Storage.
3. Select the Disable checkbox.
4. Click Save to save the configuration.

When you disable the external storage sever, you cannot do the following:

• Perform operation relying on the storage
• Retrieve or store data (snapshot or template)
• List data from the external storage
• Store file on Multi-Grid Manager
• Monitor the external storage
• Schedule any detach or attach operation

Multi-Grid Manager stops using the external storage server when it is disabled or reconfigured. However, files stored on the external storage server are preserved. Multi-Grid Manager uses the existing data when it is reconfigured to the external storage that has already been used.