Work with accounts using CHAP

09/16/2024 Contributors

In SolidFire storage systems, tenants can use accounts to enable clients to connect to volumes on a cluster. An account contains the Challenge-Handshake Authentication Protocol (CHAP) authentication required to access the volumes assigned to it. When you create a volume, it is assigned to a specific account.

An account can have up to two-thousand volumes assigned to it, but a volume can belong to only one account.

CHAP algorithms

Beginning with Element 12.7, secure FIPS compliant CHAP algorithms SHA1, SHA-256, and SHA3-256 are supported. With Element 12.7, when a host iSCSI initiator is creating an iSCSI session with an Element iSCSI target, it requests a list of CHAP algorithms to use. The Element iSCSI target chooses the first algorithm that it supports from the list requested by the host iSCSI initiator. To confirm that the Element iSCSI target chooses the most secure algorithm, you must configure the host iSCSI initiator to send a list of algorithms ordered from most secure, for example, SHA3-256, to least secure, for example, SHA1 or MD5. When SHA algorithms are not requested by the host iSCSI initiator, the Element iSCSI target chooses MD5, assuming the proposed algorithm list from the host contains MD5. You might need to update the host iSCSI initiator configuration to enable support for the secure algorithms.

During an Element 12.7 upgrade, if you have already updated the host iSCSI initiator configuration to send a session request with a list that includes SHA algorithms, as the storage nodes reboot, the new secure algorithms are activated and new or reconnected iSCSI sessions are established using the most secure protocol. All existing iSCSI sessions transition from MD5 to SHA during the upgrade. If you do not update the host iSCSI initiator configuration to request SHA, the existing iSCSI sessions will continue to use MD5. At a later date, after you update the host iSCSI initiator CHAP algorithms, the iSCSI sessions should transition gradually from MD5 to SHA over time based on maintenance activities that result in iSCSI session reconnects.

For example, the default host iSCSI initiator in Red Hat Enterprise Linux (RHEL) 8.3 has the node.session.auth.chap_algs = SHA3-256,SHA256,SHA1,MD5 setting commented out which results in the iSCSI initiator only using MD5. Uncommenting this setting on the host and restarting the iSCSI initiator triggers iSCSI sessions from that host to start using SHA3-256.

If required, you can use the ListISCSISessions API method to see the CHAP algorithms being used for each session.

Create an account

You can create an account to allow access to volumes.

Each account name in the system must be unique.

Select Management > Accounts.
Click Create Account.
Enter a Username.
In the CHAP Settings section, enter the following information:

Leave the credential fields blank to auto-generate either password.
- Initiator Secret for CHAP node session authentication.
- Target Secret for CHAP node session authentication.
Click Create Account.

View account details

You can view performance activity for individual accounts in a graphical format.

The graph information provides I/O and throughput information for the account. The Average and Peak activity levels are shown in increments of 10-second reporting periods. These statistics include activity for all volumes assigned to the account.

Select Management > Accounts.
Click the Actions icon for an account.
Click View Details.

Here are some of the details:

Status: The status of the account. Possible values:
- active: An active account.
- locked: A locked account.
- removed: An account that has been deleted and purged.
Active Volumes: The number of active volumes assigned to the account.
Compression: The compression efficiency score for the volumes assigned to the account.
Deduplication: The deduplication efficiency score for the volumes assigned to the account.
Thin Provisioning: The thin provisioning efficiency score for the volumes assigned to the account.
Overall Efficiency: The overall efficiency score for the volumes assigned to the account.

Edit an account

You can edit an account to change the status, change the CHAP secrets, or modify the account name.

Modifying CHAP settings in an account or removing initiators or volumes from an access group can cause initiators to lose access to volumes unexpectedly. To verify that volume access will not be lost unexpectedly, always log out iSCSI sessions that will be affected by an account or access group change, and verify that initiators can reconnect to volumes after any changes to initiator settings and cluster settings have been completed.

Persistent volumes that are associated with management services are assigned to a new account that is created during installation or upgrade. If you are using persistent volumes, do not modify or delete their associated account.

Select Management > Accounts.
Click the Actions icon for an account.
In the resulting menu, select Edit.
Optional: Edit the Username.

Optional: Click the Status drop-down list and select a different status.

Changing the status to locked terminates all iSCSI connections to the account, and the account is no longer accessible. Volumes associated with the account are maintained; however, the volumes are not iSCSI discoverable.

Optional: Under CHAP Settings, edit the Initiator Secret and Target Secret credentials used for node session authentication.

If you do not change the CHAP Settings credentials, they remain the same. If you make the credentials fields blank, the system generates new passwords.
Click Save Changes.

Delete an account

You can delete an account when it is no longer needed.

Delete and purge any volumes associated with the account before you delete the account.

Select Management > Accounts.
Click the Actions icon for the account you want to delete.
In the resulting menu, select Delete.
Confirm the action.