Spare Disks

[AsifGanai]

Hi,

We have FAS 2750 system running in HA with 1 external DS224C attached(only 12 drives are populated and 12 are free). 2 data aggregates are running on Raid DP, one on each controller. Aggregate 1 has 1 Raid Group, Aggregate 2 has 2 Raid Groups out of which 1 Raid Group has no spare drives. Both Aggregates have dedicated spare drives though.

Now my concern is what will happen if a disk failure will occur in the Raid Group with no Spares? Will it still continue working considering the fact Aggregate has spare drives.

I was looking at ONTAP Documentation which says, "A Single Spare Disk can serve as a hot spare for multiple Raid Groups". I would appreciate if someone can explain and clear my doubts. Attached image from ONTAP Documentation Center.

Regards

Asif Ali

[Ontapforrum]

In FAS, A hot spare disk is a disk that is assigned to a storage system and is ready for use, but is not in use by a RAID group and does not hold any data.

https://docs.netapp.com/ontap-9/index.jsp?topic=%2Fcom.netapp.doc.dot-cm-psmg%2FGUID-117C7EB9-F2D5-4403-9AF1-4F2618C25CA9.html

In short: Hotspare is not assigned to RAID_GROUPs/Aggregates, rather it is assigned to a storage system (Physical Node). It is available to be used/picked-up by any raid-groups (When a disk in that RG fails) as long as there is a matching spare type available on the Node where the Aggr(raidgroups) exits.

[AsifGanai]

Hi,

So does that mean if I have enough spares on a Node, I can breathe easy.

It doesn't matter if a Raid Group exists without any dedicated spares. As long as there are spares on a Node, life is good.

Please correct me if i am wrong.

Regards

Asif Ali

[Ontapforrum]

Yes, your understanding is correct. As long as there are online good spares of the matching disk type on the Node, you can breath easy 🙂

[AsifGanai]

Thank You

[liuh]

hi

If a hard disk is faulty, the system may break down within 24 hours. The faulty disk cannot be written to the system, resulting in data loss. The backup drive is used to replace a failed disk in the aggregation, not directly for data protection