cepheiden
1 Copper

EMC ScaleIO question / understanding about faulsets

Jump to solution

Hi there,

i am a little bit confused. maybe someone have some tipps.

I have 4 nodes. Two of them in one Rack/Room and the other two of them also in one Rack/Room.

----------------------------------------------

-- node1     |       node3  --

-- node2     |       node4 --

-----------------------------------------------

how i have to configure the FaultSets/SDS/Pools/Protected Domains to get a catched up a location failover (two nodes on one side) so that i have no risk of a downtime.

any ideas ?

Thx.

Tags (2)
0 Kudos
1 Solution

Accepted Solutions
pawelw1
2 Iron

Re: EMC ScaleIO question / understanding about faulsets

Jump to solution

Hi,

You need a third element in this equation - you can think of a FaultSet as of a 'big SDS' - in order to form a cluster, you need 3 SDS, or, in this case, 3 FS. You can mix them, so for example you can have 2 FS and a single SDS, 1FS and 2 SDS, 3 FS etc., but in general FS acts as a single cluster member, so you need at least three.

In this case, I would suggest you to move one machine to a third rack or add another 1-2 nodes and create third FaultSet.

Please check out ScaleIO User Guide, under 'Fault Sets' sections there's much more details about the FS.

Hope that helps!

Cheers,

Pawel

0 Kudos
3 Replies
pawelw1
2 Iron

Re: EMC ScaleIO question / understanding about faulsets

Jump to solution

Hi,

You need a third element in this equation - you can think of a FaultSet as of a 'big SDS' - in order to form a cluster, you need 3 SDS, or, in this case, 3 FS. You can mix them, so for example you can have 2 FS and a single SDS, 1FS and 2 SDS, 3 FS etc., but in general FS acts as a single cluster member, so you need at least three.

In this case, I would suggest you to move one machine to a third rack or add another 1-2 nodes and create third FaultSet.

Please check out ScaleIO User Guide, under 'Fault Sets' sections there's much more details about the FS.

Hope that helps!

Cheers,

Pawel

0 Kudos
Highlighted
cepheiden
1 Copper

Re: EMC ScaleIO question / understanding about faulsets

Jump to solution

I think i got that.

on the other hand , what i have to do to get an 2 node Fail protection ? (if they are located in one Rack / Room)

it is enough to set the spare capacity to 51% ?

0 Kudos
pawelw1
2 Iron

Re: EMC ScaleIO question / understanding about faulsets

Jump to solution

Hi,

In such a small environment losing two nodes would have quite an impact.You can try to set spare capacity to 51%, but that will seriously limit your capacity. In general, ScaleIO allows losing a single SDS at a time in a Protection Domain - how losing more affects you greatly depends on the configuration, load, used capacity etc.

Best regards,

Pawel

0 Kudos