Method for raid striped I/O request generation using a shared scatter gather list
First Claim
Patent Images
1. A method for processing an I/O request, comprising steps of:
- receiving an I/O request from a host;
generating a scatter gather list according to parameters of the I/O request, the scatter gather list including a flag field for providing parameter information, the flag field being different and separate from either a length field or an address field;
dividing the I/O request from the host into a plurality of physical I/O requests; and
performing each of the plurality of physical I/O requests in conjunction with the scatter gather list,wherein data is transferable to and from a disk array,wherein the step of dividina the I/O recjuest is accomplished through parameters including a set of absolute start and absolute end addresses of contiguous memory.
7 Assignments
0 Petitions
Accused Products
Abstract
A code efficient transfer method in response to a single host I/O request generates a single scatter gather list. The disk array controller transforms the single host I/O request into multiple physical I/O requests. Each of these multiple physical I/O requests uses the single scatter gather list to perform the data transfer operation. Each physical I/O request corresponds to the data transfer of one data stripe. The data stripe is an initial or header stripe of about 0.5K or a stripe of at least 64K.
52 Citations
11 Claims
-
1. A method for processing an I/O request, comprising steps of:
-
receiving an I/O request from a host; generating a scatter gather list according to parameters of the I/O request, the scatter gather list including a flag field for providing parameter information, the flag field being different and separate from either a length field or an address field; dividing the I/O request from the host into a plurality of physical I/O requests; and performing each of the plurality of physical I/O requests in conjunction with the scatter gather list, wherein data is transferable to and from a disk array, wherein the step of dividina the I/O recjuest is accomplished through parameters including a set of absolute start and absolute end addresses of contiguous memory. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A system of data transfer in a redundant array of independent disks (RAID) system, comprising:
-
means for generating multiple physical I/O requests from a host I/O request via parameters, the parameters including a set of absolute start and absolute end addresses of contiguous memory; means for traversing a scatter gather list, the scatter gather list including a flag field for providing parameter information, the flag field being different and separate from either a length field or an address field; and means for transferring data between disk drives of the RAID system and the host using the means for traversing the scatter gather list and the means for generating multiple physical I/O requests in which each of the multiple physical I/O requests results in the transfer of data to or from a data stripe on one of the disk drives.
-
Specification