A CDE Definition
(1) (Hierarchical Storage Management) The automatic movement of files from hard disk to slower, less-expensive storage media. The typical hierarchy is from magnetic disk to optical disc to tape, or from magnetic disk to tape. HSM software constantly monitors hard disk capacity and moves data from one storage level to the next based on age, category and other criteria as specified by the network or system administrator. HSM often includes a system for routine backup as well.
When a file is moved off the hard disk, it is replaced with a small stub file that indicates where the backup file is located.
Tier 0 Storage
Increasingly, solid state drives (SSDs) are used to hold data that are most frequently accessed and are a level higher than the hard disks. Consequently, data may migrate back and forth between the hard disk and SSD before being stored on optical and tape drives. See tape backup, active archiving, demigration and solid state drive.
(2) (Hardware Security Module) A device that provides strong security for storing root keys for PKI, blockchain and other cryptographic functions. See PKI and cold wallet.
A Very Safe Place
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Click any of the following categories for a list of fundamental terms.