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845
EMC ScaleIO question / understanding about faulsets
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.
pawelw1
306 Posts
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November 23rd, 2016 06:00
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
cepheiden
2 Posts
0
November 23rd, 2016 07:00
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% ?
pawelw1
306 Posts
0
November 24th, 2016 06:00
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