cryptsetup-luksSuspend - suspends an active device and wipes the key
Suspends an active device (all IO operations will block and accesses to the device will wait indefinitely) and wipes the encryption key from kernel memory. Needs kernel 2.6.19 or later.
While the luksSuspend operation wipes encryption keys from memory, it does not remove possible plaintext data in various caches or in-kernel metadata for mounted filesystems.
After this operation, you have to use luksResume to reinstate the encryption key and unblock the device or close to remove the mapped device.
<options> can be [--header, --disable-locks].
WARNING: Never suspend the device on which the cryptsetup binary resides.