File access method, system, and host

A system comprising:

• a distributed storage system comprising a management node, multiple storage nodes, and a network device, wherein local virtual address space of each storage node in the distributed storage system is corresponding to a part of a global virtual address space of the distributed storage system;
• and
• a host comprising a processor, a memory storing a program to be executed by the processor, the program comprising instructions for:
• obtaining information of a first virtual space of a to-be-accessed target file, wherein the first virtual space is space allocated in the global virtual address space by the management node to the to-be-accessed target file;
• allocating, in a local virtual address space of the host, second virtual space to the to-be-accessed target file according to the information of the first virtual space;
• converting, according to a correspondence between the first virtual space and the second virtual space, a second access request of accessing the second virtual space into a first access request of accessing the first virtual space, wherein the first access request comprises an address of the first virtual space, and the address of the first virtual space comprises device information of a first storage node, and the first storage node is a storage node that is in the multiple storage nodes and stores the to-be-accessed target file, and wherein a bit quantity of the address of the first virtual space is 2N, and N is a bit quantity of an address of local virtual address space of the first storage node, and N most significant bits of the address of the first virtual space comprise the device information of the first storage node, and N least significant bits of the address of the first virtual space are the address of the local virtual address space that is in the first storage node and that is used to store the to-be-accessed target file;
• and
• sending the first access request to the network device, causing the network device to route the first access request to the first storage node according to the device information of the first storage node in the address of the first virtual space.

A host comprising:

• a processor;
• a memory storing a program to be executed by the processor, the program comprising instructions for:
• obtaining information of a first virtual space of a to-be-accessed target file, wherein the first virtual space is space allocated in a global virtual address space of a distributed storage system by a management node in the distributed storage system to the to-be-accessed target file, and local virtual address space of each storage node in the distributed storage system is corresponding to a part of the global virtual address space;
• allocating, in a local virtual address space of the host, second virtual space to the to-be-accessed target file according to the information of the first virtual space;
• and
• converting, according to a correspondence between the first virtual space and the second virtual space, a second access request of accessing the second virtual space into a first access request of accessing the first virtual space, wherein the first access request comprises an address of the first virtual space, the address of the first virtual space comprises device information of a first storage node, and the first storage node is a storage node that is in multiple storage nodes and stores the to-be-accessed target file, and wherein a bit quantity of the address of the first virtual space is 2N, and N is a bit quantity of an address of local virtual address space of the first storage node, and N most significant bits of the address of the first virtual space comprise the device information of the first storage node, and N least significant bits of the address of the first virtual space are the address of the local virtual address space that is in the first storage node and that is used to store the to-be-accessed target file;
• and
• a network interface, coupled to the processor and configured to send the first access request to a network device in the distributed storage system, wherein the network device routes the first access request to the first storage node according to the device information of the first storage node in the address of the first virtual space.