Multipath storage system and method of operating thereof

摘要

There is provided a method of operating a multipath storage system, the method comprises: identifying a primary storage control port configured to be responsible for a given LBA range and a secondary storage control port configured to have secondary responsibility for the given LBA range; reducing, in a manner unaffecting respective inbound I/O operation, outbound I/O operation related to the given LBA range and occurring at the primary storage control port, thereby causing a situation requiring switching all respective I/O requests to an alternating path; analyzing responsive changes in outbound I/O operation related to the given LBA range and occurring at the secondary storage control port, and verifying operability of switching to the alternating path in accordance with the obtained results. Outbound I/O operation can be reduced with the help of a routine configured to identify inbound I/O requests directed to the given LBA range and to put these requests on hold for a delay period, thus giving rise to delayed I/O requests, wherein the delay period is configured to be long enough to enable switching to an alternating path.

主权项

1. A method of operating a multipath storage system, the method comprising:
identifying a primary storage control port configured for providing a primary path to a given logical block address (LBA) range and a secondary storage control port configured for providing an alternate path to the given LBA range; reducing an outbound I/O operation related to the given LBA range and occurring at the primary storage control port, thereby causing a situation requiring switching all I/O requests directed to the given LBA range to the alternate path; wherein the reducing comprises:
(a) identifying all the I/O requests directed to the given LBA range, and(b) putting all the I/O requests directed to the given LBA range on hold for a delay period, thus giving rise to delayed I/O requests; wherein the delay period exceeds a time of an I/O delay required to enable switching of all the I/O requests directed to the given LBA range to the alternate path; and analyzing responsive changes in the outbound I/O operation related to the given LBA range and occurring at the secondary storage control port, and verifying operability of switching of all the I/O requests directed to the given LBA range to the alternate path in accordance with results obtained from the analyzing.