IBM ESS Alert : Potential for SSD data loss after extended shutdown.

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There are considerations, which should be made if you are planning on shutting down an SSD based system for an extended period. The JEDEC spec for Enterprise SSD drives requires that the drives retain data for a minimum of 3 months at 40C. This means that after 3 months of a system being powered off in an environment that is at 40C or less, there is a potential of data loss and/or drive failures. This power off time limitation is due to the physical characteristics of flash SSD media's gradual loss of electrical charge over an extended power down period. There is a potential for data loss and/or flash cell characteristic shift, leading to drive failure.

Affected Products: 

IBM ESS 3000

IBM ESS 3200

IBM ESS 3500

IBM ESS GSxs model

IBM ESS GH model

IBM recommends the following: 

• Always perform regular backups and make sure you have recently backed your system up prior to extended shutdowns.  Using a flash-based storage system as a backup and then turning it off is not a best practice.

• A system (and its enclosed drives) should be powered up at least 2 weeks after 2 months of system power off.   If a drive has an error indicating it is at end-of-life, we recommend not powering off the system for extended periods of time.  Flash-based storage systems consume far less energy than rotating mechanical media so leaving it powered on is a viable option even in the most energy constrained data centers. 

• Proper environmental control procedures should be kept in place to ensure systems are experiencing less than 40C always, even if the systems are powered down.

If, after installation, the system has been powered off longer than 7 days, the system will automatically start an ESS background scrub routine designed to read the data and rewrite only if we find a problem.  An ESS system has strong end-to-end checksumming and RAID consistency checks to detect and fix errors within the data.