"external array with two contollers" what do you mean with this? my english is not that good 🙂 do you mean the powervault md1000 ?
That is correct; either a PERC6E with dual connections to an MD1000, an MD1000 connected to an MD3000/i or for when you put the drive directly into an MD3000/i (or MD3200/3600).
Member since 2003
Yes like that. MD3000 and greater. MD1000 and greater. EMC Storage etc. These systems have 2 contollers for redundancy and also other things like load balancing. A SAS disk can connect to both controllers but only 1 is active. If a contoller fails the disk will use the other connection(port) to continue working. A SATA disk is single port so can only physically connect to one controller. If that controller fails then the disk will go offline. The Interposer contains logic(chips) that turn the single port into dual port so it will function like a SAS disk. The interposer does other stuff as well not sure what though. On EMC arrays it fools the bus into thinking the disk has a 4gb interface not 3gb.
Very good answer. I called dell support to explain the purpose of interposers and the guy from dell just kept aaaa aaaa well... well... :)) no clean answer...