The important differences between these 2 methods are as follows:
1. vol copy only copies entire volumes, ndmpcopy can copy at any level (even down to a single file). 2. vol copy is a level 0 copy only. Ndmpcopy can do file-level incrementals 3. vol copy is a physical copy, ndmpcopy is logical. Where this can matter is that vol copy doesn't care what your file layou is because it doesn't have to walk the directories. Ndmpcopy's performance can be affected by the data layout (e.g. lots of small files will perform worse than a few large ones, etc.). It also means that vol copy brings over all of the snapshots in one pass. Ndmpcopy doesn't do this.
In general vol copy is probably faster, or at least not slower than ndmpcopy in the worst case. But it's probably good to know the differences in how they work.
-- Adam Fox adamfox@netapp.com
-----Original Message----- From: David McWilliams [mailto:davidkmcw@gmail.com] Sent: Wednesday, August 20, 2008 1:09 PM To: toasters@mathworks.com Subject: Ndmpcopy v vol copy
We are adding a shelf of faster disks onto our existing FAS270C. We want to copy our Oracle database volume from the existing disk to the new shelf. We have considered usig either ndmpcopy or vol copy. Is there a performance Enhancement of one over the other, or is there a better method?
Thanks, David