Basically, with two SDS going down at the same time, you are facing a DU situation. It applies to a single Protection Domain, so if you have more than one, you can survive single SDS failure in each PD at a time.
When one SDS is in the maintenance mode (and the rebuild has finished), you can disable another SDS in the PD, but please remember that you might run out of space if you shut down too many of them simultaneously, so just keep that in mind.
Hope that helps - let me know if you have any other questions!
ok i have been doing maintenace recently and when i put the sds into maintenance mode the rebuild doesnt happen until the sds is taken back out of m-mode
DU = Data Unavailability; basically you might not be able to access some of your data.
Fault Sets logically group SDS that have a high chance of failing at the same time - typically, SDS located in the same physical rack (there's a chance that all of them will go down together due to power failure etc.) - so ScaleIO knows not to put both copies of the data in the same Fault Set.
Please check out "Fault Sets" section in ScaleIO UserGuide for more details on these.
Well, in theory there shouldn't be any rebuld when entering the maintenance mode, but basically every time you do something with the SDS it's better to have a look at the GUI and make sure there's no rebuild/rebalance going on, just to be on the safe side.
pawelw1
306 Posts
1
November 18th, 2016 00:00
Hi Mick,
Basically, with two SDS going down at the same time, you are facing a DU situation. It applies to a single Protection Domain, so if you have more than one, you can survive single SDS failure in each PD at a time.
When one SDS is in the maintenance mode (and the rebuild has finished), you can disable another SDS in the PD, but please remember that you might run out of space if you shut down too many of them simultaneously, so just keep that in mind.
Hope that helps - let me know if you have any other questions!
Pawel
mickhooly
23 Posts
0
November 18th, 2016 02:00
ok i have been doing maintenace recently and when i put the sds into maintenance mode the rebuild doesnt happen until the sds is taken back out of m-mode
pawelw1
306 Posts
1
November 18th, 2016 02:00
DU = Data Unavailability; basically you might not be able to access some of your data.
Fault Sets logically group SDS that have a high chance of failing at the same time - typically, SDS located in the same physical rack (there's a chance that all of them will go down together due to power failure etc.) - so ScaleIO knows not to put both copies of the data in the same Fault Set.
Please check out "Fault Sets" section in ScaleIO UserGuide for more details on these.
Cheers,
Pawel
mickhooly
23 Posts
0
November 18th, 2016 02:00
sorry, DU?
And what is the purpose of fault sets ?
pawelw1
306 Posts
0
November 18th, 2016 03:00
Well, in theory there shouldn't be any rebuld when entering the maintenance mode, but basically every time you do something with the SDS it's better to have a look at the GUI and make sure there's no rebuild/rebalance going on, just to be on the safe side.