STORAGE SYSTEM WITH VIRTUAL DISKS

摘要

An administrator provisions a virtual disk in a remote storage platform and defines policies for that virtual disk. A virtual machine writes to and reads from the storage platform using any storage protocol. Virtual disk data within a failed storage pool is migrated to different storage pools while still respecting the policies of each virtual disk. Snapshot and revert commands are given for a virtual disk at a particular point in time and overhead is minimal. A virtual disk is cloned utilizing snapshot information and no data need be copied. Any number of Zookeeper clusters are executing in a coordinated fashion within the storage platform, thus increasing overall throughput. A timestamp is generated that guarantees a monotonically increasing counter, even upon a crash of a virtual machine. Any virtual disk has a “hybrid cloud aware” policy in which one replica of the virtual disk is stored in a public cloud.

主权项

1. A method of generating a timestamp for a virtual disk that increases monotonically, said method comprising:
retrieving from memory of a computer server a generation number associated with said virtual disk; retrieving from said memory of said computer server a counter number associated with said virtual disk; combining said generation number and said counter number in order to generate a first timestamp for said virtual disk; upon detecting that said memory of said computer server has been lost, incrementing a persistent generation number in persistent storage of a remote storage platform, said persistent generation number being equivalent to said lost generation number before said incrementing; resetting said counter number in said memory of said computer; and combining said incremented generation number and said counter number in order to generate a second timestamp for said virtual disk whereby said first timestamp and said second timestamp are monotonically increasing values.