Patent ID: 9632881
Date: 2017-04-25
CPC Classifications: G06F

Claim:
1. A method comprising: running a virtual machine (VM) at a first site; sending I/Os from the VM to a first virtual volume (VVol) at the first site; mirroring the first VVol with a second VVol at a second site; sending I/Os for the first VVol to a third VVol at a third site; detecting failure at the first site; running the VM at the second site; reading a second backlog, the second backlog being synchronized with a first backlog on the first site, the first backlog storing I/Os that have not been completed to the third VVol; adding the second backlog to a delta marker on the second site, the delta marker storing differences between the third VVol and the second VVol; replicating the second VVol to the third VVol after adding the second backlog to the delta marker; receiving a notification to select an erase point in the delta marker; receiving notification that latest I/O arrived at the third VVol; and erasing data in the delta marker up to the erase point.