Root-data-data spare partitions

[LORENZO_CONTI]

Hello,

could someone please help clarify if that documentation applies to root-data-data partitioning?
Do I have to leave 2 different ssd with 2 spare partitions (root+data) for the HA pair?

Here's what i have on one of our AFF 

cluster::> storage aggregate show-spare-disks

Original Owner: cluster-01
 Pool0
  Root-Data1-Data2 Partitioned Spares
                                                              Local    Local
                                                               Data     Root Physical
 Disk             Type   Class          RPM Checksum         Usable   Usable     Size Status
 ---------------- ------ ----------- ------ -------------- -------- -------- -------- --------
 1.0.7            SSD    solid-state      - block                0B  37.42GB   3.49TB zeroed
 1.0.19           SSD    solid-state      - block            1.73TB       0B   3.49TB zeroed

Original Owner: cluster-02
 Pool0
  Root-Data1-Data2 Partitioned Spares
                                                              Local    Local
                                                               Data     Root Physical
 Disk             Type   Class          RPM Checksum         Usable   Usable     Size Status
 ---------------- ------ ----------- ------ -------------- -------- -------- -------- --------
 1.0.19           SSD    solid-state      - block            1.73TB  37.42GB   3.49TB zeroed
3 entries were displayed.

Thank you 

Lorenzo 

[TMACMD · Accepted solution]

If all your drives are RD2 (Root-Data-Data) partitioned, then they all show as "shared".

Technically speaking one drive on either controller can be used as a spare on both. Why?

If Any drive fails, it fails on both nodes. This causes a reconstruction on both nodes since the drive is partitioned between both. If there is a WHOLE (unpartitioned) drive, it is automatically partitioned to match what is there and reconstruction occurs on all three partitions (Root/Data/Data).

If you have a mix of RD2 and whole SSDs (unpartitioned), then you should leave at least one unpartitioned drive per controller.

[LORENZO_CONTI]

Sorry, 

maybe I have not explained very well...

In my example, do is better to align spare partitions in order to have all spares on 1.0.19? (of course better to have 2 full expensive spare drives) 🙂

[LORENZO_CONTI]

It's now clear that the mentioned doc applies to root-data and not to root-data-data partitioning.

Thanks a lot