HP MSA 1040 HP MSA 1040 CLI Reference Guide (762782-001, March 2014) - Page 340

trust Description Enables an offline vdisk to be brought online for emergency data recovery. This command must be enabled before each use. If used improperly this command can cause unstable operation and data loss; before use, carefully read the cautions and procedures below. The trust command provides an opportunity to recover data from a vdisk that has gone offline due to disk failure. The command forces a resynchronization of the metadata (as well as time and date stamps) that unifies members of a vdisk, and essentially puts the vdisk back into an accessible state. As long as the failed disks are operable, data can be read from the disks and restored to another location. From examining the state of the disks, if the command determines that the trust operation is unsafe-that it may result in an unstable vdisk with data corruption-the command will fail. You may then seek assistance from technical support or run the command with a special parameter to acknowledge the risk of proceeding. Otherwise, if the command determines the operation to be safe, the command will proceed. When the "trusted" vdisk is back online, back up its data and audit the data to make sure that it is intact. Then delete that vdisk, create a new vdisk, and restore data from the backup to the new vdisk. Using a trusted vdisk is only a disaster-recovery measure; the vdisk has no tolerance for any additional failures. The following procedure outlines the general steps for performing a trust operation, but the best procedure to follow for your situation may vary from this procedure. Before starting this procedure, consult the online troubleshooting guide at http://www.hp.com/support/msa2040/Troubleshooting to determine if the trust operation is applicable to your situation and for guidance to perform it. CAUTION: 1. Do not use the trust command when the storage system is unstable; for example, if there are many power or topology-change events. 2. The trust command cannot be run on a quarantined vdisk. In many cases the vdisk will be automatically dequarantined. If you cannot resolve the issue that caused the disk to become quarantined such that it is automatically dequarantined, and if the trust operation is applicable to your situation, dequarantine the vdisk, confirm it is in offline state by using the show vdisks command, and then proceed to trust. 3. Never update controller-module, expansion-module, or disk firmware when the vdisk is offline. 4. Never clear unwritten data cache when a vdisk is offline. 5. Do not use the trust command on a vdisk that went offline during vdisk expansion. 6. Do not use the trust command on a vdisk with status CRIT. Instead, add spares and let the system reconstruct the vdisk. The trust command must be used in CLI console mode. Steps for running the trust command 1. Disable background scrub of disks and vdisks to avoid running scrubs automatically. 2. Identify the cause for the vdisk going offline. 3. If an external issue (power, cabling, and so forth) caused the vdisk to go offline, fix the external issue before continuing to the next step. 4. Disable host access to the offline vdisk. In a single-controller configuration, disconnect the host-port cables. In a dual-controller configuration: a. Determine the owning controller of the offline vdisk. b. As a precautionary measure, remove the host-port cables of the owning controller of the offline vdisk. 340