----- Original Message ----- From: "Chris Lamb" skeezics@measurecast.com To: toasters@mathworks.com Sent: Sunday, October 08, 2000 10:38 AM Subject: Re: mixing 18GB and 36GB drives
If you have a raid group of 18GB drives, and add a 36GB drive, the 36GB drive becomes the new parity drive. The old 18GB parity drive becomes a data drive, giving you 18GB of space. After that, all 36GB drives you add give you the full 36GB of space.
The "problem" with this is that you end up with hot spots
I'm quite aware of the "hot spot" problem. The poster said there was a space issue:
"Seperating different disc sizes into different RAID groups avoids various sorts of disc space wastage in the short term. But it doesn't alter the fact that if you have a mixture of disc sizes within a volume, you are stuck with that state for as long as the volume exists: you can never expand a data plane to effectively use a larger disc."
There's no space wastage and no problem expanding the data plane.
Bruce