Multiple luns in Disk group
HI ,
When ever we want a file system to be extended we are addign a new LUN to the diskgroup .In this way we are adding multiple disks in a diskgroup
My question what is the best method to get th...
From a volume manager point of view the
- Disadvantage of adding a new LUN is that it will take longer to import and deport the diskgroups with more VM disks, but we are talking fractions of a second, so you would have to add several LUNs to be able to notice any difference.
- Advanage of adding a new LUN is that there is more flexability in the volume layout so if the volume was originally created on one LUN, if you add a new LUN to extend then you could convert layout to a stripe in VM over the 2 LUNs which will improve I/O throughput, but generally this extra throughput is not required for most applications. So for example suppose using one LUN you can acheive 100Mb/s, then if you only ever write at a max of 40Mb/s, then increasing 100Mb/s throughput is not of any use.
There also maybe Pros and Cons from an array point of view.
Mike
- Disadvantage of adding a new LUN is that it will take longer to import and deport the diskgroups with more VM disks, but we are talking fractions of a second, so you would have to add several LUNs to be able to notice any difference.
