during normal BCV establish, M2 of the mirrored BCV is fixed and only the M1 "joins" the STD device and becomes M3. As soon as it's split, it "goes" back to the fixed M2 and syncs it up. During protected establish BCV's M1 and M2 both move and join the STD device, thus become M3 and M4. If i understand description of concurrent BCV establish, you can not use protected establish in conjunction with concurrent as there are only 4 mirror positions to fill. All of these applies to your standard BCVs, STD ..TimeFinder emulation functions differently.

I was writing a longer post but my PC died ... :-/

However I can only add that you need -protbcvest option when you establish a protected BCV and want to establish both M1 and M2 .. But this feature requires 5670 code or later.
Obviously you also need a couple of free mirror position ...

Concurrent BCV's is when two seperate BCV's are established to a standard device, one would occupy the M3 position and the other would occupy the M4 position.

As for using mirrored BCV's, Dynamox is correct in that it is the M1 that gets established. The only time that the M2 would get established would be if there was a drive failure on the M1.

MikeMac,

is it a true statement that you can not establish two 2-way mirror BCVs concurrently (with protected establish) because you only have 4 mirror positions.

Thanks

Periya, for your first part of the question, I am currently looking into it.

Dynomax, if I am reading this right, you are correct. In order to have a Protected BCV Establish you need to have two available mirror positions. Also, in order to have concurrent BCV's you need to have two available mirror positions. So, with only four mirror positions per device and a typical device is using two of the mirror positions (mirrored, RAID, ect.) you can not concurrent protected BCV's established.

I checked with our configuration specialists and there are no flag settings for concurrent BCV's.

Ok Thank you.That M3 position is actual volume space of BCV M1 that will be modified by the enginuity code as M3. Am I right? So far I thought there is some equal space of hyper (as M3) in STD volume side ll be created and mirrored to establish the BCV M1

Dynamox by default when you establish a 2-way-mir BCV only the M1 will be moved to the STD device. Thus you CAN establish 2 different 2-way-mir BCV concurrently.
If you want to establish both mirrors of your BCV you need the very special option I mentioned above.

When you split a "default established" 2-way-mir BCV the M2 will sync from M1.
When you split a "-protbcvest" 2-way-mir BCV both M1 and M2 (actually M3 and M4 of your STD) will split at the same time.

What is a BCV ??
A BCV is a very special volume whose mirrors can be moved dynamically and attached as additional mirror protection to other (STD) devices.

When you establish a BCV, the M1 position of the BCV will be removed from the BCV itself and attached as M3 or M4 to the STD device. That's why a BCV goes NR. If you have an unprotected BCV and you remove its M1 (the only mirror position usually used) you obviously can't either read or write from the BCV itself .. that's why your BCVs goes NR when you establish them. Obviously it isn't really true for protected BCVs but to keep things consistent (and since the code is writing data in your devices) they are kept NR too.