CONTAP-471456：ASAr2 节点在接管后无法启动，因为它找不到 mroot 的 pool0

问题描述

• 启动时，ASAr2 节点显示错误：cannot import 'pool0': no such pool available
• 在 ASAr2 节点上运行 ONTAP Upgrade 时出现此问题，从任何 <9.16.1P3 到 9.16.1P3
• 被接管的节点无法启动，而是在串行控制台或 BMC 系统控制台上显示：
  WARNING: netapp_mount_mroot_early: Giving up waiting for mroot after 304 seconds.
=mroot_encryption: geli attach: start
=mroot_encryption: attempting to get default key; executing '/usr/sbin/cryptomod_mroot -d'
=mroot_encryption: key digest 54c0c4ff70881b4c305aae3f4f5a40a2475ac8a3de196846f746c392b36e5a3e
=mroot_encryption: geli attach(default)
=mroot_encryption: attempting to get normal key; executing '/usr/sbin/cryptomod_mroot'
=mroot_encryption: key digest 54c0c4ff70881b4c305aae3f4f5a40a2475ac8a3de196846f746c392b36e5a3e
=mroot_encryption: geli setkey(normal)
=Note, that the master key encrypted with old keys and/or passphrase may still exists in a metadata backup file.
=mroot_encryption: _cleanup: start
=mroot_encryption: key digest 54c0c4ff70881b4c305aae3f4f5a40a2475ac8a3de196846f746c392b36e5a3e
=mroot_encryption: geli attach: end
=cannot import 'pool0': no such pool available
...
=cannot import 'pool0': no such pool available
ERROR: Please communicate the above information to support.
ERROR: Mroot unavailable. Recovery may be required. Halting startup.
Halting system
  
• 从 9.16.1P3 之前的内核启动受影响的节点时（例如使用boot_backup从 LOADER 提示符开始）- 它正常启动并等待交还