Guys,
We're getting ready to do a DC move, so I'm working to setup all my SnapMirror relationships to hopefully mirror all my data between my two pairs (all in one cluster right now). The idea being that if one pair doesn't make the move, we have our data elsewhere. No, we don't have any swing gear, the system is out of Netapp support, and we do have alot of spare space to mirror with. Whew. :-)
So I found the Netapp documents on "SVM Root Volume Protection Express Guide" from 2016 and I've started to implement it here, because if the worse case happens and one pair doesn't make it through the move due to damage or loss or catastrophe, I need to be able to bring up as much data as possible, as quickly as possible.
https://library.netapp.com/ecm/ecm_download_file/ECMLP2496241
I do have some questions for you all, to see what other people are doing, and what are current best practices and real life issues to watch out for.
First, I did change my setup so that I mirror every 5 minutes, instead of hourly as given in the quick guide. Since we use Netbackup to make clones of volumes to backup, that should hopefully work ok, but I worry that now I need to add in a:
snapmirror update-ls-set -source-vserver <vs> -source-volume rootvol
after I create a new clone, to make sure that the backup server will see this clone volume and junction path. Has anyone run into this issue and is your workaround to just do the update by hand, or do you just wait for the change to replicate?
Second, this document recommends one LS mirror per-head in a cluster. With a four node cluster, this seems a little crazy, especially since I've never had any problems when doing failovers during upgrades in the past. My main goal is to just have the mirrors on seperate pairs. What do people think? Is one rootvol and one rootvol_m1 mirror per VServer enough?
Third, if I go with just one LS mirror per-pair, I think it looks like I really need to make two mirrors, one for the source pair, and one for the opposite pair. Which seems like a pain to manage, increases the number of volumes and SM relationships to manage, etc. Since my main focus is NOT performance, since it's been working just fine without LS mirrors in the past, is just having one LS mirror good enough?
Cheers, John