Handling sector edges
AssigneeEMC Corporation
InventorsRobert P. Foley, Ronald D. Proulx, Adi Ofer
Life of this patent
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Abstract
A method is used in handling sector edges. Input/output (I/O) requests to a storage device are handled. The I/O requests use a different sector size format than that of the storage device. An I/O request is received for a write operation at a logical address of a virtual device. The write operation specifies new data to be written to the virtual device. A logical sector associated with the logical address is determined. The logical sector is mapped to a portion of a physical sector of the storage device. The sector edge of the physical sector is read into a RAID-protected memory. The read sector edge is written together with the new data to the storage device.
Claims8
A method for use in handling sector edges, the method comprising:
- handling input/output (I/O) requests to a storage device, wherein the I/O requests use a different sector size format than that of the storage device;
- receiving an I/O request for a write operation at a logical address of a virtual device, the write operation specifying new data to be written to the virtual device;
- determining that the I/O request for the write operation is not aligned to an optimum block size;
- determining a logical sector associated with the logical address;
- mapping the logical sector to one or more physical sectors of the storage device;
- performing a pre-read of the determined logical sector and logical sectors in any portion of the one or more physical sectors that will not be updated;
- checking the consistency of the pre-read data at a RAID level;
- and
- issuing a write from the RAID level to a different level combining the pre-read data and new data.
A system for use in handling sector edges, the system comprising:
- first logic handling input/output (I/O) requests to a storage device, wherein the I/O requests use a different sector size format than that of the storage device;
- second logic receiving an I/O request for a write operation at a logical address of a virtual device, the write operation specifying new data to be written to the virtual device;
- third logic determining that the I/O request for the write operation is not aligned to an optimum block size;
- fourth logic determining a logical sector associated with the logical address;
- fifth logic mapping the logical sector to one or more physical sectors of the storage device;
- sixth logic performing a pre-read of the determined logical sector and logical sectors in any portion of the one or more physical sectors that will not be updated;
- seventh logic checking the consistency of the pre-read data at a RAID level;
- and
- eighth logic issuing a write from the RAID level to a different level combining the pre-read data and new data.
Dependencies are inferred from the claim text.