Signaling impending out of storage condition from a virtual tape drive

• US 9,552,370 B1
• Filed: 06/27/2013
• Issued: 01/24/2017
• Est. Priority Date: 06/27/2013
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: McCloskey, Larry W., Offhaus, Bruce F.
• Primary Examiner(s): Arjomandi, Noosha
• Application Number:
  US13/929,558
• Time in Patent Office: 1,307 Days
• Field of Search: 707/822
• US Class Current: 1/1
• CPC Class Codes: G06F 16/188 Virtual file systems

Abstract

In one embodiment, a method of informing a mainframe that a filesystem storing a plurality of virtual tapes is filled relative to a particular threshold includes returning, responsive to a write request to a virtual tape in the filesystem, a message indicating that the filesystem is filled relative to the particular threshold. The method can also include monitoring a plurality of filesystems for free space remaining on each of the plurality of filesystems. The method can additionally include indicating, in a data structure stored in a memory, a particular filesystem that is filled above the particular threshold. The data structure can be at least one of a table and a list. The method can further include mounting, responsive to a request to mount a particular virtual tape that is on a filesystem indicated in the data structure as being above the particular threshold, the particular virtual tape as read-only.

Claims

1. A method of informing a host system that a filesystem storing a plurality of virtual tapes is filled relative to a particular free space threshold, the method comprising:

writing data to the filesystem responsive to a write request from the host system, the writing causing the filesystem to be filled above the free space threshold, the free space threshold being less than a maximum capacity of the file system;

returning to the host system, responsive to the write request from the host system to a virtual tape stored by the filesystem, a message indicating that the filesystem has limited free space relative to the particular free space threshold;

monitoring a plurality of filesystems, each filesystem storing a plurality of virtual tapes, for free space remaining on each of the plurality of filesystems;

indicating, in a data structure stored in a memory, a particular filesystem that is filled above the particular threshold; and

mounting, responsive to a request to mount a particular virtual tape that is on a filesystem indicated in the data structure as being above the particular threshold, the particular virtual tape as read-only.

2. The method of claim 1, wherein the data structure is at least one of a table and a list.

3. The method of claim 1, further comprising, responsive to a request to initiate a scratch mount, directing the request to a filesystem that is filled below the particular threshold.

4. The method of claim 1, further comprising, responsive to a usage balancing move request, directing the request to a filesystem that is filled below the particular threshold.

5. The method of claim 1, further comprising configuring the particular threshold responsive to a user input.

6. The method of claim 1, wherein the message indicates that the system is filled above the particular threshold.

7. A system for informing a host system that a filesystem storing a plurality of virtual tapes is filled relative to a particular free space threshold, the system comprising:

a processor; and

a memory with computer code instructions stored thereon, the memory operatively coupled to the processor such that the computer code instructions cause the processor to implement;

a messaging module configured to return to the host system, responsive to a write request from the host system to a virtual tape stored by the filesystem, a message indicating that the filesystem has limited free space relative to the particular free space threshold;

a monitor module configured to monitor a plurality of filesystems, each filesystem storing a plurality of virtual tapes, for free space remaining on each of the plurality of filesystems;

a tracking module configured to indicate, in a data structure stored in a memory, a particular filesystem that is filled above the particular threshold; and

a request direction module configured to mount, responsive to a request to mount a particular virtual tape that is on a filesystem indicated in the data structure as being above the particular threshold, the particular virtual tape as read-only;

the filesystem configured to write data, responsive to a write request from the host system, the writing causing the filesystem to be filled above the free space threshold, the free space threshold being less than a maximum capacity of the file system.

8. The system of claim 7, wherein the data structure is at least one of a table and a list.

9. The system of claim 7, further comprising a request direction module configured to direct, responsive to a request to initiate a scratch mount, the request to a filesystem that is filled below the particular threshold.

10. The system of claim 7, further comprising a request direction module configured to direct, responsive to a usage balancing move request, the request to a filesystem that is filled below the particular threshold.

11. The system of claim 7, further comprising a settings module configured to set the particular threshold responsive to a user input.

12. The system of claim 7, wherein the message indicates that the system is filled above the particular threshold.

13. A non-transitory computer-readable medium configured to store instructions for informing a host system that a filesystem storing a plurality of virtual tapes is filled relative to a particular free space threshold, the instructions, when loaded and executed by a processor, cause the processor to:

write data to the filesystem responsive to a write request from the host system, the writing causing the filesystem to be filled above the free space threshold, the free space threshold being less than a maximum capacity of the file system;

return to the host system, responsive to a write request from the host system to a virtual tape stored by the filesystem, a message indicating that the filesystem has limited free space relative to the particular free space threshold;

monitor a plurality of filesystems, each filesystem storing a plurality of virtual tapes, for free space remaining on each of the plurality of filesystems;

indicate, in a data structure stored in a memory, a particular filesystem that is filled above the particular threshold; and

mount, responsive to a request to mount a particular virtual tape that is on a filesystem indicated in the data structure as being above the particular threshold, the particular virtual tape as read-only.

14. The non-transitory computer-readable medium of claim 13, wherein the message indicates that the system is filled above the particular threshold.