Hot spare
Hot spares are redundant system components that are permanently installed as replacements in computer systems and to which, in the event of an error, are automatically switched over using auto swap. These hot spare components are also called hot standby components. Such hot standby components can be hard disk drives , tape drives or controllers , for example .
Hot spare hard drives
A hot spare disk is a (in a system in reserve save ) held (usually unused) hard drive . If another disk fails, the hot spare disk is automatically integrated in place of the defective disk during operation ( hot ). The hard disk is switched off in error-free operation and is only switched on by the software when required. This serves to protect the mechanical components of the hard disk. This is particularly useful in a RAID , in which the data on the defective hard drive can be automatically reconstructed (rebuild).
During the rebuild on the hot spare disk, the performance of the RAID drops significantly. With RAID-1, the rebuild takes less time than with RAID-5, since with RAID-5 additional parity information has to be reconstructed. The more hard disks there are in a RAID 5 array, the longer the rebuild will take and the worse the performance if a hard disk is defective.
Individual evidence
- ↑ Hotspare , itwissen.de
- ↑ Rolf Dietze, Tatjana Heuser, Jörg Schilling: OpenSolaris for users, administrators and data centers: From the first steps to productive operation on Sparc, PC and PowerPC-based platforms, Springer Science & Business Media, 2006, p. 256 [1]
- ↑ EMC Education Services: Information Storage and Management: Storing, Managing, and Protecting Digital Information, John Wiley & Sons, 2010, p. 68 [2]