March 9, 2017 at 7:25 am
Morning All,
Can a single File Share Witness (about 10GB in size) be used to provide quorum for multiple clusters.
I have Location 3 a FSW
I have 3 clusters both split over location1 and location2
Can the single Location3 FSW support 3 independent clusters?
Cheers
Alex
March 9, 2017 at 11:30 am
I am sure you can, however I would create a folder for each cluster and separate the actual FSW paths from each other.
Since it's only a file share, the Cluster won't take ownership of it as it would with a shared disk.
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This thing is addressing problems that dont exist. Its solution-ism at its worst. We are dumbing down machines that are inherently superior. - Gilfoyle
March 9, 2017 at 12:30 pm
alex.sqldba - Thursday, March 9, 2017 7:25 AMMorning All,Can a single File Share Witness (about 10GB in size) be used to provide quorum for multiple clusters.
I have Location 3 a FSW
I have 3 clusters both split over location1 and location2
Can the single Location3 FSW support 3 independent clusters?Cheers
Alex
Yes, in fact the fileshare witness for each cluster just needs to sit on a well connected server, under a dedicated fileshare to ensure security
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"Ya can't make an omelette without breaking just a few eggs" 😉
March 13, 2017 at 1:53 am
Cheers Perry. That makes life easier 🙂
March 13, 2017 at 5:10 am
alex.sqldba - Monday, March 13, 2017 1:53 AMCheers Perry. That makes life easier 🙂
Note also the fileshare witness should be a separate site to the actual nodes to provide true witness capability
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"Ya can't make an omelette without breaking just a few eggs" 😉
March 13, 2017 at 5:13 am
Yes, we have 3 locations and the FSW is sited at location #3
Cheers!
March 14, 2017 at 1:55 am
Whilst on this subject, is there benefit to having a FSW in location #3 when you have a 3 node cluster split over two other locations?
I understand that will create 4 even votes -- but I read somewhere as a passing statement (online, of which I cannot find now) that they create a FSW and give it an extra vote to provide 5 votes. I am wondering what the benefit is?
I also have here a 3 node AlwaysOn type cluster and no FSW in a third location but one can be fairly easily added, I just can't quite see what it would do?
Any thoughts, or a link to a good explanation of when to and when not to creat fileshare or disk witnesses.
Cheers
Alex
March 14, 2017 at 4:27 am
alex.sqldba - Tuesday, March 14, 2017 1:55 AMWhilst on this subject, is there benefit to having a FSW in location #3 when you have a 3 node cluster split over two other locations?I understand that will create 4 even votes -- but I read somewhere as a passing statement (online, of which I cannot find now) that they create a FSW and give it an extra vote to provide 5 votes. I am wondering what the benefit is?
I also have here a 3 node AlwaysOn type cluster and no FSW in a third location but one can be fairly easily added, I just can't quite see what it would do?
Any thoughts, or a link to a good explanation of when to and when not to creat fileshare or disk witnesses.
Cheers
Alex
if you have a 3 node cluster you do not need a witness (disk or fileshare), you use Majority Node Set as your quorum model
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"Ya can't make an omelette without breaking just a few eggs" 😉
March 14, 2017 at 4:33 am
Yup that was how I understood it but this comment somewhere else (still searching) described a peculiar scenario in which he/she needed a witness with increased voting weight.
Hmmm, never mind... If I find it, ill post a link.
Cheers!
March 14, 2017 at 7:53 am
alex.sqldba - Tuesday, March 14, 2017 4:33 AMYup that was how I understood it but this comment somewhere else (still searching) described a peculiar scenario in which he/she needed a witness with increased voting weight.Hmmm, never mind... If I find it, ill post a link.
Cheers!
The cluster should always have an odd number of voting participants, there are times when you may have an odd number of nodes but need to introduce a witness, if for instance you do not want a DR node having a vote in the cluster.
In this case, when you add the witness you also remove a vote from one of the voting members to maintain the odd vote count
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"Ya can't make an omelette without breaking just a few eggs" 😉
March 14, 2017 at 8:56 am
Interesting part for me is why you'd not want the DR node to have a vote? When would this situation likely arise?
March 14, 2017 at 9:01 am
if the cluster is not designed correctly and worst case scenario.
Llets say you had 1 primary node in main site and 2 dr nodes in dr site and all have a vote, 3 nodes in all.
Any problems in the cluster and the 2 DR outweigh the primary and your primary site is offline
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"Ya can't make an omelette without breaking just a few eggs" 😉
March 14, 2017 at 9:03 am
Ahhhhh! Right.
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