I heard that it's not a good idea to create 1 volume from 2 different SATA controllers. For example, if I have (2) 4-port SATA controllers, it's better to create (2) different volumes, (1) on each controller. Is that correct or has anyone tried creating 1 volume so they can have a big 16TB array if using 2TB drives.
it's quite the opposite. the more controllers, generally the better it will perform. it's all about bandwidth. if you constrain your pool to a single adapter, you're constrained to the bandwidth of that single device. if you have more than one, you can get the bandwidth of all of them. for example. if you have a 4 port PCI-e 1x card, you have 2 gb/s of bandwidth. but if you have 2, 2 port PCI-e cards, you'll have 2 gb/s per card, for a total of 4 gb/s.
the only reason to Not use a controler is if it has poor performance. for example, a PCI cardthe entire PCI bus is 1 gb/s if you combined a high end PCI-e 4x card with a PCI card, you're going to limit your speed.
there is no real hard and fast rule, you need to think about your situation and how the disks are allowed to be accessed by the hardware you have. for example, multiple PCI-e devices can communicate simultaneously (or at least close) where as PCI devices have to trade off. so having 2 PCI controllers in the same pool (worse yet same vdev) would impact performance. but having multiple PCI-e cards would be a good thing.
