The only reason to look at symdisk output is if you want to include space that is completely unallocated which you could get just from the symdisk -list.  The symdev output shows usable space so you need to calculate the "raw space" which would include protection.  The simplest thing to do is then add up your mirrored devices and multiple the storage used by 2 (if you want raw capacity) and for Raid-5 (3+1) multiple each device.

To be 100% correct you should be using 1024 for MB/GB/TB conversions as well not 1000 since that can make a big difference as the numbers get big.

Hope this helps.

Thanks.  That's why I wanted the logic check.  1024 is what I should have been doing.  Typical brain dead mistake

I am trying to come up with total usable capacity.  Which means I need to figure in symdisk list (which is raw), then come up with the raid level considerations and add that number to the total from symdev list -noport -disk_group x.

The mirrored stuff is easy, as you mentioned.  Multiples of 2.  For raid-5 (3+1) I assume a 25% overhead (which I assume to be correct, maybe someone can verify it for me).

Maybe our term for usable is different - to me usable is what is available to a server when you present a device.

I think by usable you mean the raw storage capacity you could use to create devices.

If that is all you are after this is pretty simple - just use symdisk and add-up the column showing unallocated space.  However keep in mind this could be skewed because you may have like 1GB at the tail of a drive that is too small for you to use.

Yes for Raid-5 (3+1) it is very close to 25% overhead (you lose a full drive) so you multiple by 1.3333  (divide by 0.75) to get the raw number used.  In practice it is not an exact 75% (I believe you lose an extra track or 2 on for overhead) but close enough for what you probably want to see.

Ok, looks like my logic is fairly close.  Thanks for the help in going over it for me to double check me, I really appreciate it!

-Steve