What is hot spare in storage?
What is hot spare in storage?
Hot spare disks are preparatory disk drives that are kept on active standby for use when a disk drive fails. The Global Hot Spare function enables hot spare disks to be used for any RAID group. When a disk drive in a RAID group fails, data on the disk drive is rebuilt automatically on the hot spare disk in background.
What is a hot spare in RAID technology?
An extra disk drive in a RAID configuration that is ready and waiting to be put into action automatically when another drive fails. Using the RAID algorithms, the missing data from the faulty drive is reconstructed and written to the hot spare. When the bad drive is replaced, it then becomes the hot spare.
How many hot spares should I have?
For all other Data ONTAP disk types, you should have at least one matching or appropriate hot spare available for each kind of disk installed in your storage system. However, having two available hot spares for all disks provides the best protection against disk failure.
Does RAID 10 need hot spare?
A RAID 10 configuration requires two disks per RAID 1, and can have only one hot spare disk. A RAID 50 configuration requires three disks per RAID 5, and can have up to two hot spare disks.
How does RAID 5 hot spare work?
Hot spare is a drive that acts as a stand by drive in RAID 1, RAID 5 or RAID 6 volume. It is fully functional drive that contains no data and is not used during normal operation. If a drive from the volume fails, the controller reconstructs the data from the failed drive to the hot spare drive.
What is the purpose of a hot spare in a RAID array?
In storage, hot spares are used to replace failing or failed disks in a RAID configuration. Originally, a hot spare had to be included in the array being protected, but through advances in controller design and SAN architecture, several arrays on the same SAN can now share hot spares.
Do I need hot spare with RAID 5?
Hot spares provide protection from hardware failure because slices from RAID 1 or RAID 5 volumes are automatically replaced and resynchronized when they fail. The hot spare can be used temporarily until a failed submirror or RAID 5 volume slice can be either fixed or replaced.