Implementing large block random write hot spare SSD for SMR RAID

摘要

A method and a storage system are provided for implementing a sustained large block random write performance mechanism for shingled magnetic recording (SMR) drives in a redundant array of inexpensive disks (RAID). A Solid State Drive (SSD) is provided with the SMR drives in the RAID. The SSD is used in a hot spare mode, which is activated when a large block random-write event is identified for a SMR drive in the RAID. In the hot spare mode, the SSD temporarily receives new incoming writes for the identified SMR drive. Then the identified SMR drive is updated from the SSD to restore the state of the identified SMR drive, and operations continue with normal writing only using the SMR drives in the RAID.

主权项

1. A method for implementing a sustained large block random write performance mechanism for multiple shingled magnetic recording (SMR) drives in a redundant array of inexpensive disks (RAID) comprising:
providing a single Solid State Drive (SSD) with the multiple SMR drives in the RAID; using said SSD only in a hot spare mode with the multiple SMR drives, identifying a large block random write event for a SMR drive in the RAID; activating said SSD in said hot spare mode responsive to the identified large block random write event for the SMR drive; temporarily receiving new incoming writes for the identified SMR drive with said SSD preempting use of the identified SMR drive; ending the hot spare mode for said SSD and continuing with normal writing only using SMR drives in the RAID; and identifying a recovery mode for the identified SMR drive responsive to ending said hot spare mode, and moving data from said SSD to the identified SMR drive.