CANCELLATION OF INDIVIDUAL LOGICAL VOLUMES IN PREMIGRATION CHAINS

• US 20090083501A1
• Filed: 09/24/2007
• Published: 03/26/2009
• Est. Priority Date: 09/24/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kishi, Gregory Tad, Kibuse, Yuuji, Masuda, Koichi, Friauf, Cheryl Marie, Iwasaki, Norie
• Granted Patent: US 7,882,328 B2
• Time in Patent Office: Days
• US Class Current: 711/158
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2212/213 Tape storage
• CPC Class Codes: G06F 2212/224 Disk storage
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox

Abstract

Provided are techniques for cancellation of premigration of a member in a chain. A set of premigration messages are received, wherein a separate premigration message is received for each logical volume in a chain of logical volumes. While processing the premigration messages in order of receipt of each of the premigration messages, a cancel message indicating that premigration of a logical volume in the chain is to be cancelled is received. In response to determining that the logical volume whose premigration is to be cancelled has not already been transferred to physical storage media, premigration of the logical volume is cancelled by removing a premigration message for that logical volume from the set of premigration messages and premigration of each other logical volume in the chain of logical volumes is continued in order of receipt.

Claims

1. A computer-implemented method, comprising:

receiving a set of premigration messages, wherein a separate premigration message is received for each logical volume in a chain of logical volumes;

while processing the premigration messages in order of receipt of each of the premigration messages,

receiving a cancel message indicating that premigration of a logical volume in the chain is to be cancelled;

in response to determining that the logical volume whose premigration is to be cancelled has not already been transferred to physical storage media,

cancelling premigration of the logical volume by removing a premigration message for that logical volume from the set of premigration messages; and

continuing to premigrate each other logical volume in the chain of logical volumes in order of receipt.

2. The method of claim 1, wherein each of the premigration messages includes a unique message identifier shared by the premigration messages in the chain, a chain member identifier, a total number of members in the chain, a logical volume identifier, and premigration indicators.

3. The method of claim 1, further comprising:

under control of a data cancel thread executing at a data mover,

monitoring for cancel messages;

recognizing that a cancel message has been received; and

issuing the cancel message to a data move thread executing at the data mover.

4. The method of claim 1, wherein processing the premigration messages in order of receipt further comprises:

for each of the premigration messages,

attempting to transfer a logical volume identified in the premigration message from cache to the physical storage media; and

returning a status message indicating whether the premigration was successful.

5. The method of claim 4, wherein the status message indicates that the premigration was successful even though the cancel message was received.

6. The method of claim 4, wherein the status message indicates that the premigration failed because the cancel message was received.

7. The method of claim 1, wherein each of the premigration messages indicates that a logical volume in the chain is to be transferred from cache to physical storage media.