3.9.3.2 Lock Volume Snapshots

A volume snapshot is a thinly-provisioned read-only point-in-time copy of a volume.

Starting with Oracle Exadata System Software release 26.1.0, you can lock a volume snapshot to prevent its deletion before a specified future date and time. You can also make the lock immutable, which prevents users from removing the lock or changing it to expire earlier.

To set or change a lock on a volume snapshot, use the chvolumesnapshot command and set the following attributes:

• lockExpiryTime: Specifies the lock expiry time. The value must be an ISO 8601-formatted future date and time.

• lockImmutable: Boolean value (true or false) indicating whether the lock is immutable:

  • A mutable (variable) lock (lockImmutable=false) prevents the volume snapshot from being deleted before the lock expiry time (lockExpiryTime).

  • An immutable lock (lockImmutable=true) prevents the volume snapshot from being deleted before the lock expiry time (lockExpiryTime), and also prevents users from removing the lock or changing it to expire earlier.

For example:

@> chvolumesnapshot vol0001_snap0001_50e52177583f4be4bad68ac20b65001e --attributes lockExpiryTime=2050-06-30T13:00:00,lockImmutable=false

In the example, the volume snapshot (vol0001_snap0001_50e52177583f4be4bad68ac20b65001e) is locked with a variable lock until 1PM on June 30, 2050.

After locking a volume snapshot:

• You can unlock a volume snapshot with a variable lock (lockImmutable=false) by setting the lockExpiryTime attribute to null.

  For example:

  @> chvolumesnapshot vol0001_snap0001_50e52177583f4be4bad68ac20b65001e --attributes lockExpiryTime=null

  Note:

  You cannot unlock a volume snapshot with an immutable lock (lockImmutable=true).

• You can convert a variable lock into an immutable lock by setting the lockImmutable attribute to true. You must also re-specify the lock expiry time (lockExpiryTime).

  For example:

  @> chvolumesnapshot vol0001_snap0001_50e52177583f4be4bad68ac20b65001e --attributes lockExpiryTime=2050-06-30T13:00:00,lockImmutable=true

• You can extend an immutable lock by setting the lockExpiryTime attribute to a later date and time. In the command, you must also include lockImmutable=true.

  For example:

  @> chvolumesnapshot vol0001_snap0001_50e52177583f4be4bad68ac20b65001e --attributes lockExpiryTime=2051-12-31T19:00:00,lockImmutable=true

To view the status of a locked volume snapshot, use the lsvolumesnapshot command and examine the lockExpiryTime, lockImmutable, and lockStatus attributes.

For example:

@> lsvolumesnapshot vol0001_snap0001_50e52177583f4be4bad68ac20b65001e --attributes lockExpiryTime,lockImmutable,lockStatus
lockExpiryTime                   2051-12-31T19:00:00+00:00
lockImmutable                    true
lockStatus                       locked

The lockExpiryTime, lockImmutable, and lockStatus attributes display only for volume snapshots with a lockExpiryTime setting.

The lockStatus attribute is a derived property that indicates the current status of the lock. The value is locked when the lock is active, or expired when the lock expiry time has passed.

Note:

At any time, an Exascale cluster administrator who has the cl_admin privilege can modify an immutable lock or delete a locked volume snapshot.