Patent ID: 9632701
Date: 2017-04-25
CPC Classifications: G06F

Claim:
1. A storage system comprising: a first storage apparatus and a second storage apparatus, each of which includes a plurality of storage devices and a controller being configured to provide a same virtual apparatus identifier and a respective logical volume, which is one volume of a high-availability (HA) pair of volumes, with a same virtual volume identifier to a computer which sends a write request or a read request, so that either of the first storage apparatus and the second storage apparatus receives an I/O request to a virtual volume composed of the HA pair from the computer, wherein the controller of the first storage apparatus is configured to provide the respective logical volume as a first logical volume of the HA pair to the computer, wherein the controller of the second storage apparatus is configured to provide the respective logical volume as a second logical volume of the HA pair to the computer, wherein, when either of the first storage apparatus and the second storage apparatus receives the write request to write data to the virtual volume, the controller of the first storage apparatus and the controller of the second storage apparatus are configured to write the write data of the write request to the second logical volume after the write data is written first to the first logical volume, wherein, when the write request to the virtual volume is received, the controller of the first storage apparatus is configured to manage an exclusive lock regarding the write request, wherein the controller of the first storage apparatus is configured to set the exclusive lock, prohibiting both writing to and reading from a storage area in the first logical volume before the write data of the write request is written to the first logical volume, wherein the controller of the first storage apparatus is configured to release the exclusive lock after the write data is written to both the first logical volume and the second logical volume, and wherein the controller of the second storage apparatus is not configured to set the exclusive lock regarding the write request, and accepts a read request to the second logical volume while the exclusive lock is set in the first storage apparatus.