Partition Failover in EV8?
Hello,
I have a question to clustering. The setup is an EV 8 server pointing to two storage devices. When the primary storage device fails, the second one should be used to continue writing data (without any service restart etc).
1.) I was wondering if I can simply set up two partitions, one as open and one as ready. When the first one fails it would go into ready state and the second one would go in the open state. Is something like this possible?
2.) Somebody told me about using Building Blocks, but from reading the Admin Guide this seems only a solution for when the EV server fails. We rather want to detect a storage failure and write to a different storage device in that case.
3.) Would it be possible to set up MS Clustert that way - e.g. it would detect that a storage device fails rather than EV server and then fail over the UNC Path? If so would this be possbile withouit any service restarts?
Thanks a lot for any hints in this direction,
bjorn
What you're looking to do *may* be possible but not advisable
However partition roll over is based on Date or Size restrictionsSo for instance on the date one, some people like to have partitions based on a particular year or quarter, so you could have 2011 Q1 that rolls over in march to 2011 Q2 etc
However there is no roll over based on whether the storage is available or not.
Another thing, is the storage going to be mirrored so the same data is available on both storage devices? because if it is, then the idea of the partition roll over isn't exactly necessary, but if it isn't then you would just be writing new data and your old data wouldn't be accessibleThe problem with the approach at that point would be that you have fragmented datasets that are out of sync, so what then happens if the primary storage becomes available again? all the data written to the fail-over storage would have to come across and is only really good if the storage is the exact same path.
Last but not least if you were going to try and test this and in the event of actual failovers also, you would end up with many small partitions, and also if the storage isn't mirrored or replicated then you would lose some form of SIS along the way, and having mentioned SIS, i'm not quite sure how EV would react if it believes that an attachment has already been stored and what will happen when it tries to verify it.For instance if you have E:\Vault Stores\Ptn1 and you have a document shared called myWordDoc.docx thats 1.2MB and then you fail over to E:\Vault Stores\Ptn2 and the same document comes in, EV would normally say this item is the same as an item already stored, so i'm going to share it
I don't know whether it would error because the item is not available, or whether it would simply just say "the items there, i'm not going to check whether its available" and then when you try to open the item again it errors out because the sis part isn't available.Either that or it may check for the existance and then it says not available so i'm going to share this as a new file, and now you have duplicated data in your storage
As for the cluster option, i believe you can have HA (High Availability) set for storage failures, however part of the cluster failover will be to stop services on one server and then start on the other server (if it can do it gracefully enough)
To be honest though, what you want to do with clustering and storage isn't advisable but what i would suggest is having a look in to the VMWare ESX fail over solutions that are a lot quicker and a lot more seamless and look at having replicated or mirrored storage, though i believe the cost for those would go up some.
Personally i would invest more in having the storage be more highly available and concentrate less on the EV servers
