Method and apparatus for managing device reservation

• US 7,587,530 B2
• Filed: 08/20/2003
• Issued: 09/08/2009
• Est. Priority Date: 08/20/2003
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: McCarthy, John G.
• Primary Examiner(s): Patel; Niketa I
• Application Number:
  US10/645,721
• Publication Number:
  US 20050044281A1
• Time in Patent Office: 2,211 Days
• Field of Search: 710/6, 710/36, 710/45, 710/38, 710/46, 710/40, 710/200, 710/244, 709/228
• US Class Current: 710/36
• CPC Class Codes: G06F 13/372 using a time-dependent priority, e.g. individually loaded time counters or time slot
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0682 Tape device

Abstract

Methods and apparatus are disclosed for managing device reservation. In one embodiment, upon receiving a device command from a first host, a device targeted by the device command is reserved for the first host and a reservation time period for expiration of the reservation status is set.

Claims

1. A method comprising:

upon receiving a device command from a first host for a data transfer operation to a storage device,

i) reserving for the first host the storage device targeted by the device command;

ii) setting a reservation time period for expiration of a reservation of the storage device, the reservation time period being determined based on a command type of the device command, wherein the device command comprises one of a write command, a rewind command, a read command, a load command, an unload command, and a seek command; and

iii) preventing other hosts from interfering with the data transfer operation between the first host and the storage device during the reservation time period.

2. The method of claim 1, further comprising upon receiving a second device command from the first host, resetting the reservation time period.

3. The method of claim 1, further comprising:

upon receiving a device command targeted to the device from a second host,

determining if the device is reserved; and

if the device is reserved to a host other than the second host, denying the device command from the second host.

4. The method of claim 3, wherein determining if the device is reserved comprises determining if the reservation time period has expired.

5. The method of claim 3, further comprising if the device is not reserved, executing the device command from the second host.

6. The method of claim 3, wherein the device command from the second host comprises a clear command.

7. The method of claim 1, wherein the device command comprises a tape device command.

8. The method of claim 1, wherein the device command comprises a disk device command.

9. The method of claim 1, wherein the device command comprises a Small Computer System Interface (SCSI) command.