And as long as your system isn't hammered, you have the magical thing called write cache
If you read the virtual copy whitepaper (
https://h20195.www2.hpe.com/v2/GetPDF.a ... 486ENW.pdf) it states pretty early in the text:
Quote:
HPE 3PAR Virtual Copy implements an
efficient variant of copy-on-write (COW) and redirect-on-write (ROW) methodologies. For COW, the HPE 3PAR OS uses a delayed copy-onwrite (DCOW) process that eliminates any performance impact to host I/O. DCOW is used for snapshots of fully provisioned and thinly
provisioned volumes. DCOW relegates the reading of the original data, updating of the base volume with the new data, and the copying of
the original data to a background process after the write update has been acknowledged by the host.
So what I'm reading is that it may impact the overall maximum "performance capacity" of the 3PAR as is has to do some background IOs but the host performance (as in latency) shouldn't be affected. So if you're running your array at 90% of it's performance capacity it might be a really bad idea to start doing snapshots but if it is just lurking along at 25% you shouldn't notice any difference.