1. A piezoceramic material having a composition represented by Pbm{Zr1-x-y-zTixSny(Sb1-nNbn)z}O3 where 1.000\u2266m\u22661.075, 0.470\u2266x<0.490, 0.020\u2266y\u22660.040, 0<n<1.000 and 0<z\u22660.025 and a crystallite size of 30 to 39 nm.
2. A piezoceramic material according to claim 1, wherein the piezoceramic material has a piezoelectric constant d33 of 340 pCN or larger.
3. A piezoelectric element comprising an element body formed of a piezoceramic material according to claim 1.
4. A non-resonance knock sensor, comprising:
a piezoelectric element having an element body formed of a piezoceramic material according to claim 1 and at least one pair of electrodes arranged on the element body;
a support member having a support portion to support the piezoelectric element;
a weighting member disposed on the piezoelectric element to press the piezoelectric element against the support portion; and
a resin molded part covering the piezoelectric element and the weighting member from the outside of the support member.
5. A non-resonance knock sensor, comprising:
a piezoelectric element having an element body formed of a piezoceramic material according to claim 1 and a pair of first and second electrodes arranged on the element body;
a support member having a support portion to support the piezoelectric element; and
a weighting member disposed on the piezoelectric element to press the piezoelectric element against the support portion,
wherein at least part of a surface of the first electrode faces a bottom surface of the weighting member when the piezoelectric element and the weighting member are projected in a thickness direction of the piezoelectric element; and the ratio of an area of said at least part of the surface of the first electrode to an area of the bottom surface of the weighting member is 45% or higher.
6. A piezoceramic material having a composition represented by Pbm{Zr1-x-y-zTixSny(Sb1-nNbn)z}O3 where 1.000\u2266m\u22661.075, 0.470\u2266x<0.490, 0.020\u2266y\u22660.040, 0<n<1.000 and 0<z\u22660.025 and a piezoelectric constant d33 of 340 pCN or larger.
7. A piezoelectric element comprising an element body formed of a piezoceramic material according to claim 6.
8. A piezoelectric sensor, comprising:
a piezoelectric element having an element body formed of a piezoceramic material according to claim 6 and at least one pair of electrodes arranged on the element body;
a support member having a support portion to support the piezoelectric element;
a weighting member disposed on the piezoelectric element to press the piezoelectric element against the support portion; and
a resin molded part covering the piezoelectric element and the weighting member from the outside of the support member.
9. A piezoelectric sensor comprising:
a piezoelectric element having an element body formed of a piezoceramic material according to claim 6 and a pair of first and second electrodes arranged on the element body;
a support member having a support portion to support the piezoelectric element; and
a weighting member disposed on the piezoelectric element to press the piezoelectric element against the support portion,
wherein at least part of a surface of the first electrode faces a bottom surface of the weighting member when the piezoelectric element and the weighting member are projected in a thickness direction of the piezoelectric element; and the ratio of an area of said at least part of the surface of the first electrode to an area of the bottom surface of the weighting member is 45% or higher.
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 of operating a data management system, comprising:
selecting a virtual disk file;
identifying unused portions of the virtual disk file; and
writing metadata for the virtual disk file in the unused portions of the virtual disk file.
2. The method of claim 1, wherein the virtual disk file is stored on a data storage volume and further comprising, after writing the metadata, storing the virtual disk file in a second data storage volume.
3. The method of claim 2, wherein identifying the unused portions of the virtual disk file comprises analyzing a bitmap of the data storage volume.
4. The method of claim 1, wherein identifying the unused portions of the virtual disk file stops once enough unused portions have been identified to hold all of the metadata.
5. The method of claim 1, wherein the unused portions of the virtual disk file comprise unallocated blocks of data that comprise the virtual disk file.
6. The method of claim 1, wherein the virtual disk file is a Virtual Machine Disk (VMDK) file format.
7. A data management system, comprising:
a processor configured to:
select a virtual disk file;
identify unused portions of the virtual disk file; and
write metadata for the virtual disk file in the unused portions of the virtual disk file.
8. The system of claim 7, further comprising:
a data storage volume configured to store the virtual disk file;
a second data storage volume configured to store the virtual disk file after the metadata is written.
9. The system of claim 7, wherein the processor is configured to identify the unused portions of the virtual disk file by analyzing a bitmap of the data storage volume.
10. The system of claim 7, wherein the processor is configured to stop identifying the unused portions of the virtual disk file once enough unused portions have been identified to hold all of the metadata.
11. The system of claim 7, wherein the unused portions of the virtual disk file comprise unallocated blocks of data that comprise the virtual disk file.
12. The system of claim 7, wherein the virtual disk file is a Virtual Machine Disk (VMDK) file format.
13. A computer readable medium having instructions stored thereon for operating a data management system, wherein the instructions, when executed by the data management system, instruct the data management system to:
select a virtual disk file;
identify unused portions of the virtual disk file; and
write metadata for the virtual disk file in the unused portions of the virtual disk file.
14. The computer readable medium of claim 13, wherein the virtual disk file is stored on a storage volume and wherein the instructions further direct the data management system to store the virtual disk file in a second data storage volume after the metadata is written.
15. The computer readable medium of claim 14, wherein the instructions further direct the data management system to identify the unused portions of the virtual disk file by analyzing a bitmap of the data storage volume.
16. The computer readable medium of claim 13, wherein the instructions further direct the data management system to stop identifying the unused portions of the virtual disk file once enough unused portions have been identified to hold all of the metadata.
17. The computer readable medium of claim 13, wherein the unused portions of the virtual disk file comprise unallocated blocks of data that comprise the virtual disk file.
18. The computer readable medium of claim 13, wherein the virtual disk file is a Virtual Machine Disk (VMDK) file format.