1. A method of detecting a watermark in a first signal, the method comprising the steps of:
receiving (601) the first signal potentially having a watermark embedded in an original signal;
receiving (603) a second signal corresponding to the original signal; segmenting (605) the signal into a plurality of segments each corresponding to a watermark symbol;
and for each of the segments performing the steps of:
determining (607) a first characteristic for a first section of the segment in response to a set of data values of the first signal in the first section and set of data values of the second signal in the first section, determining (609) a second characteristic for a second section of the segment in response to a set of data values of the first signal in the second section and set of data values of the second signal in the second section, and
determining (611) a watermark symbol estimate for the segment in response to the first characteristic and the second characteristic; and
determining (615) if a watermark is embedded by comparison of the watermark symbol estimates with a reference watermark symbol pattern.
2. A method as claimed in claim 1 wherein the step of determining (607) the first characteristic comprises determining an envelope characteristic of the first signal in the first section.
3. A method as claimed in claim 1 wherein the step of determining (607) the first characteristic comprises determining an envelope characteristic of the second signal in the first section.
4. A method as claimed in claim 1 wherein the step of determining (607) the first characteristic comprises determining the first characteristic as a first relationship between an envelope characteristic of the first signal in the first section and an envelope characteristic of the second signal in the first section.
5. A method as claimed in claim 4 wherein the first relationship is a ratio.
6. A method as claimed in claim 5 wherein the step of determining (609) the second characteristic comprises determining the second characteristic as a second ratio between an envelope characteristic of the first signal in the second section and an envelope characteristic of the second signal in the second section and the step (615) of determining a watermark symbol estimate comprises determining the watermark symbol estimate as a mathematical function of the first ratio and the second ratio.
7. A method as claimed in claim 6 wherein the mathematical relationship comprises a subtraction.
8. A method as claimed in claim 1 wherein a symbol shape of the watermark symbols is a substantially bi-phase window symbol shape.
9. A method as claimed in claim 1 further comprising the step of determining a property of the first characteristic in response to a symbol shape of the watermark symbols.
10. A method as claimed in claim 1 further comprising the step of extracting a first portion of the first signal and performing the segmentation and watermark symbol estimation by processing of the first portion only.
11. A method as claimed in claim 1 wherein the step of extracting the first portion comprises filtering the first signal.
12. A method as claimed in claim 1 wherein the watermark is a multiplicative watermark.
13. An apparatus for detecting a watermark in a first signal, the method comprising:
means (501) for receiving the first signal potentially having a watermark embedded in an original signal;
means (503) for receiving a second signal corresponding to the original signal;
means (505, 507) for segmenting the signal into a plurality of segments each corresponding to a watermark symbol;
and means (509, 511, 513) for, for each of the segments,
determining a first characteristic for a first section of the segment in response to a set of data values of the first signal in the first section and set of data values of the second signal in the first section,
determining a second characteristic for a second section of the segment in response to a set of data values of the first signal in the second section and set of data values of the second signal in the second section, and
determining a watermark symbol estimate for the segment in response to the first characteristic and the second characteristic; and
means (515) for determining if a watermark is embedded by comparison of the watermark symbol estimates with a reference watermark symbol pattern.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method comprising:
logically migrating a storage device out of a plurality of storage devices storing data in a storage system without physically decoupling the storage device from the storage system, said logically migrating the storage device comprising selecting the storage device based on a geometric configuration of the plurality of storage devices;
performing a maintenance operation on the storage device without interrupting storage service provided by the storage system;
returning the migrated storage device to the plurality of storage devices as a spare storage device in the storage system after performing the maintenance operation on the storage device if the storage device does not fail; and
notifying a user to remove the storage device from the storage system after performing the maintenance operation on the storage device if the storage device fails.
2. The method of claim 1, wherein the plurality of storage devices includes a Redundant Array of Independent Disks (RAID) group and a spare storage device.
3. The method of claim 2, wherein logically migrating the storage device comprises:
selecting the storage device out of the RAID group;
copying data from the selected storage device to the spare storage device; and
replacing the selected storage device with the spare storage device in the RAID group.
4. The method of claim 3, wherein selecting the storage device comprises selecting the storage device based on a speed of each of the plurality of the storage devices.
5. The method of claim 1, wherein the maintenance operation comprises:
checking firmware upgradability of the storage device; and
upgrading firmware of the storage device if an upgrade of the firmware is available.
6. The method of claim 1, wherein the maintenance operation comprises checking the storage device to confirm a reported error in the storage device.
7. The method of claim 6, wherein the error includes a media error.
8. The method of claim 6, wherein the error includes a hardware error.
9. The method of claim 1, wherein the maintenance operation comprises checking the storage device for failure information, which includes statistics on errors found in the storage device.
10. The method of claim 1, wherein the maintenance operation comprises causing the storage device to run a self-diagnostic routine.
11. The method of claim 1, wherein the maintenance operation comprises writing a plurality of data patterns on the storage device to sanitize the storage device.
12. A method comprising:
in response to an error report on a storage device, logically migrating the storage device out of a plurality of storage devices storing data in a storage system without physically decoupling the storage device from the storage system;
checking the migrated storage device to verify the error report without interrupting data service provided by the storage system;
returning the migrated storage device to the plurality of storage devices as a spare storage device in the storage system if the error report is not confirmed; and
notifying a user to remove the storage device from the storage system if the error report is confirmed.
13. The method of claim 12, wherein the error report indicates a media error in the storage device.
14. The method of claim 12, wherein the error report indicates a hardware error in the storage device.
15. A computer readable storage medium that stores instructions which, if executed by a processor, will cause the processor to perform operations comprising:
logically migrating a storage device out of a plurality of storage devices storing data in a storage system periodically without physically decoupling the storage device from the storage system;
performing a maintenance operation on the storage device without interrupting storage service provided by the storage system;
returning the storage device to the plurality of storage devices as a spare storage device in the storage system if the storage device has no error; and
notifying a user to remove the storage device from the storage system if an error is found in the storage device, wherein the error may include a media error or a hardware error in the storage device.
16. The computer readable storage medium of claim 15, wherein the maintenance operation comprises:
checking firmware upgradability of the storage device; and
upgrading firmware of the storage device if an upgrade of the firmware of the storage device is available.
17. The computer readable storage medium of claim 15, wherein the maintenance operation comprises checking the storage device for error.
18. The computer readable storage medium of claim 15, wherein logically migrating the storage device comprises writing a maintenance state label in a predetermined location on the storage device.
19. An apparatus comprising:
a storage adaptor;
a memory device to store a plurality of instructions; and
a processor, coupled to the memory device and the storage adaptor, to retrieve the plurality of instructions from the memory device and, in response to the plurality of instructions, to perform a plurality of operations comprising:
logically migrating a storage device out of a plurality of storage devices coupled to the storage adaptor to store data in a storage system without physically decoupling the storage device from the storage adaptor;
performing a maintenance operation on the storage device without interrupting storage service provided by the storage system;
returning the migrated storage device to the plurality of storage devices as a spare storage device in the storage system after performing the maintenance operation on the storage device if the maintenance operation is performed successfully; and
notifying a user to remove the storage device from the storage system after performing the maintenance operation on the storage device if a defect is found in the storage device.
20. The apparatus of claim 19, wherein the defect includes a media error on the storage device.
21. The apparatus of claim 19, wherein the defect includes a hardware error on the storage device.
22. The apparatus of claim 19, wherein the maintenance operation includes downloading updated firmware to the storage device.
23. The apparatus of claim 19, wherein the maintenance operation includes checking the storage device for defect.
24. The apparatus of claim 19, wherein the maintenance operation includes sanitizing the storage device.
25. The apparatus of claim 19, wherein the maintenance operation includes causing the storage device to run a self-diagnostic routine.
26. A storage system comprising:
a plurality of storage devices;
a storage server, coupled to the storage devices, to provide storage service, the storage server comprising:
a memory device to store a plurality of instructions; and
a processor, coupled to the memory device, to retrieve the plurality of instructions from the memory device and, in response to the plurality of instructions, to perform a plurality of operations comprising:
logically migrating a storage device out of the plurality of storage devices without physically decoupling the storage device from the storage server;
performing a maintenance operation on the storage device without interrupting the storage service provided;
logically returning the migrated storage device to the plurality of storage devices as a spare storage device after performing the maintenance operation on the storage device if the maintenance operation is performed successfully; and
notifying a user to physically remove the storage device after performing the maintenance operation on the storage device if a defect is found in the storage device.
27. The storage system of claim 26, wherein the plurality of storage devices includes a Redundant Array of Independent Disks (RAID) group and a spare storage device.
28. The storage system of claim 27, wherein the maintenance operation comprises:
selecting the storage device out of the RAID group based on a predetermined criterion;
copying data from the selected storage device to the spare storage device; and
making the spare storage device a member of the RAID group to replace the selected storage device.
29. A method comprising:
logically migrating a storage device out of a plurality of storage devices storing data in a storage system without physically decoupling the storage device from the storage system, the plurality of storage devices including a Redundant Array of Independent Disks (RAID) group and a spare storage device, wherein migrating the storage device comprises
selecting the storage device based on a predetermined criterion,
copying data from the selected storage device to the spare storage device, and
replacing the selected storage device with the spare storage device in RAID group;
performing a plurality of maintenance operations on the storage device without interrupting storage service provided by the storage system, wherein the plurality of maintenance operations comprise:
checking firmware upgradability of the storage device;
downloading updated firmware to the storage device if an upgrade of a firmware of the storage device is available,
checking the storage device to confirm a reported error in the storage device, wherein the reported error may include a hardware error or a media error in the storage device,
checking the storage device for failure information, which includes statistics on errors found in the storage device,
sanitizing the storage device, and
causing the storage device to run a self-diagnostic routine;
designating the storage device as spare and returning the storage device to the plurality of storage devices after performing the plurality of maintenance operations on the storage device if the storage device does not fail; and
notifying a user to remove the storage device from the storage system after performing the plurality of maintenance operations on the storage device if the storage device fails.
30. A method comprising:
means for logically migrating a storage device out of a plurality of storage devices storing data in a storage system without physically decoupling the storage device from the storage system;
means for performing a maintenance operation on the storage device without interrupting storage service provided by the storage system;
means for returning the migrated storage device to the plurality of storage devices as a spare storage device in the storage system after performing the maintenance operation on the storage device if the storage device does not fail; and
means for notifying a user to remove the storage device from the storage system after performing the maintenance operation on the storage device if the storage device fails.