What is the purpose of a hot spare in a RAID array?
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.
Is a hot spare worth it?
As is said in almost every theory, using a hot spare disk with ZFS, Solaris FMA or in any other data storage environment is a good solution as it will automatically react to damage in a Redundant Array of Independent Disks (RAID) array and a hot spare disk indeed helps to minimize the duration of a degraded array state …
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.
What is dedicated hot spare in RAID?
A dedicated hot spare is a hot spare disk that can only be used for one redundant virtual disk. It is also possible to assign a dedicated hot spare reserve to protect more than one logical drive; this is called a pool reserve.
Does RAID 6 need hot spare?
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.
Can RAID 10 have a 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.
What is the difference between global hot spare and dedicated hot spare?
Unlike “Global Hot Spare” which can be used with any RAID groups, Dedicated Hot Spare can only be used with a specific RAID group. When a disk drive fails in the RAID group with a Dedicated Hot Spare is pre-set, data on the disk drive is rebuild automatically on the dedicated hot spare disk.
What is a global hot spare?
A global hot spare is an unused backup disk that is part of the disk group. Hot spares remain in standby mode. When a hard drive that is used in a virtual disk fails, the assigned hot spare is activated to replace the failed hard drive without interrupting the system or requiring your intervention.
What are the hot spares for RAID 6?
RE: Hot spares for RAID 6. Also, note the following from the support matrix: SAS and SATA disks cannot be mixed in a disk group. A hot spare for a disk group must be a physical disk of equal or greater size than any of the member disks. The hot spare for a disk group with SAS physical disks must be a SAS disk.
Is RAID 5 worth it with a hot spare?
RAID 5 should never exist with a hot spare (warm spare.) RAID 6 is always a better use of the same drive count. There is no space/capacity advantage or cost advantage to the RAID 5 solution (but some small performance advantage) but it does a ton for mitigating things like URE risk.
How to deal with failed drives in RAID 6?
You of course should have time to replace a single failed drive with RAID 6 but I always try to put a hot spare per enclosure if I can and then just mark the replaced drive as a HS for the enclosure when it is replaced. This of course works best if all the drives are the same size in a given enclosure.
What is a hot spare for a disk group?
A hot spare for a disk group must be a physical disk of equal or greater size than any of the member disks. 02-11-2010 10:18 AM You of course should have time to replace a single failed drive with RAID 6 but I always try to put a hot spare per enclosure if I can and then just mark the replaced drive as a HS for the enclosure when it is replaced.