EV vault store partition disk size recommendation

Size recommendations would usually come down to how to most efficiently back up your EV stores But by partitions I'm guessing you are meaning physical disk partitions as opposed to the logical EV partitions correct? For instance a physical partition would be like \\mySANServer\myShare -> G:\ Where as EV partitions may be G:\Enterprise Vault Stores\Vault Store 1\Ptn1\ G:\Enterprise Vault Stores\Vault Store 1\Ptn2\ G:\Enterprise Vault Stores\Vault Store 1\Ptn3\ The reason you would create multiple partitions is for backup purposes, generally when a partition is closed, no new data will be added (unless you use collections, which is a whole different story) So rather than having a huge 1TB partition that is active and you continually backup full, you might close and open a new partition every year, like G:\Enterprise Vault Stores\Vault Store 1\Ptn1\ <-- 250gb (closed 2009) G:\Enterprise Vault Stores\Vault Store 1\Ptn2\ <-- 250gb (closed 2010) G:\Enterprise Vault Stores\Vault Store 1\Ptn3\ <-- 100GB (open since 2011) This way you might only do a full back up every month for PTN1 and PTN2. PTN3 which is actively being written to would be backed up fully as frequently as possible But because we're closing the partitions frequently, we are not taking more time than we need to on backups But when it comes to physical partitions and LUN's, I'm not sure there is any correct answer just whatever you're comfortable with, obviously the more data you put to a single location, the more you lose if that area fails Also there's some fairly sketchy ideas as to how windows performs when the file system has millions upon millions of folders and files, this could also have a negative impact again on backup speeds and DVSVR storage integrity checking speeds And finally on backups, outside of device snapshots, one of the fastest backups you can do is Flash Backups, but flash doesn't just back up the existing files, it does a block by block backup of that partition So if you have a 9TB partition and only use 200GB of it, regular backup would just get the files but flash backup would get all 9TB worth of blocks So the recommendation is to make the part to a certain size, and start the partition off small and the. Grow as you need to until you've hit that max size, then create a new partition to store data to and backup So for instance, create a 100GB LUN and backup with flash backup, when you hit 80GB, grow it some more so you don't run out of space, then when it hits say 800-900GB in size, close the partition and start writing to a new physical location