CN103827837A

CN103827837A - Method, device and system for accessing solid state disk space

Info

Publication number: CN103827837A
Application number: CN201280002464.5A
Authority: CN
Inventors: 许保亮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2012-08-22
Filing date: 2012-08-22
Publication date: 2014-05-28
Anticipated expiration: 2032-08-22
Also published as: CN103827837B; WO2014029087A1

Abstract

A method, device and system for accessing a solid state disk space. The solid state disk (SSD) space comprises at least two subgroups, and each subgroup is a subgroup obtained by equally dividing several block SETs contained in the SSD space; wherein the SETs in each of the subgroups have the same index number, and the SETs having the same offset in at least two subgroups belong to the same logic subgroup. The method comprises: mapping a block request for accessing the disk space to a first logic subgroup in the SSD space; acquiring the index number of the first SET mapped from the block request in the first logic subgroup by means of the mapping function; and writing the block request into the first SET. The embodiments of the present invention group the SSD space, thereby mapping the block request to a certain logic subgroup divided. Because each logic subgroup comprises a number of SETs identical to the number of the subgroups, uniform access to the SSD space is achieved, and the caching efficiency and the use efficiency of the SSD are improved.

Description

Method, device and system for accessing solid state disk space

Access method, the apparatus and system in solid state hard disc space

Technical field more particularly to accesses method, the apparatus and system in solid state hard disc space the present invention relates to technical field of memory.Background technology

Data center is generally made up of server, network and the part of storage device three.Solid state hard disc is progressively used in the prior art（Sol id State Disk, SSD traditional magnetic disk) is substituted as storage device, and SSD is the hard disk being made of solid-state electronic chip array, is made up of control unit and memory cell two parts, wherein memory cell is responsible for data storage, and control unit is responsible for reading, writes data.Because SSD does not include mechanical part, therefore operation need not be sought, with good random read-write performance.But, because SSD prices are higher than traditional magnetic disk, thus generally using SSD as traditional magnetic disk caching, to accelerate user to the access speed of disk.Due to SSD finite capacities, the generally capacity than disk is small, it is therefore desirable to periodically by temporarily no data write disk in SSD.

In the prior art when realizing the mapping between disk and SSD, disk space is generally divided into M parts according to SSD capacity（M is natural number）Disk subspace, SSD spaces are divided into N, and (N is natural number）Individual SET (set of blocks）, N number of SET is accordingly divided into according to the dividing mode in SSD spaces for each disk subspace.After being divided in the manner described above to disk space and SSD spaces, i-th of SET on direct mapping mode, i.e., each disk subspace is used to both map on i-th of the SET of SSD spatially between disk and SSD（I span is 1 to N), due to having M disk subspace, therefore equivalent to the SET of M SET correspondences SSD spatially on disk subspace.

In the prior art, because some data on disk space can be accessed often, these data storages correspond to fixed SET in the position of disk space, it can be seen from the mapping relations between SET on disk space and SSD spatially SET, the some SET of SSD spatially will be accessed frequently, and carry out the read-write and erasing of data；For example, it is assumed that in M disk subspace, first SET on each disk subspace is often accessed, then corresponds to SSD spaces, first SET of the SSD spatially will be accessed frequently, and thus reduce SSD buffer efficiency and service efficiency.The content of the invention

The embodiment of the present invention provides a kind of method for accessing solid state hard disc space, apparatus and system, the problem of to solve SSD buffer efficiency in the prior art and not high service efficiency.

In order to solve the above-mentioned technical problem, the embodiment of the invention discloses following technical scheme： On the one hand, a kind of method for accessing solid state hard disc space is provided, the solid-state hard disk SSD space includes at least two packets, it is each to be grouped into the obtained packet of some set of blocks SET included in the SSD spaces progress etc. point, SET in wherein described each packet has identical call number, the SET with same offset belongs to same logic groups at least two packet, and methods described includes：

The block conducted interviews to disk space request is mapped to the first logic groups of the SSD spatially；The call number for the first SET that described piece of request is mapped in first logic groups is obtained by mapping function；

Described piece of request is write into the first SET.

It is described that the block conducted interviews to disk space request is mapped to the first logic groups of the SSD spatially in the first possible implementation with reference to one side face, including：

Obtain the block conducted interviews to the disk space and ask the start offset on the disk space；The SET that described piece of request corresponding 2nd SET on the disk space is calculated according to the start offset is numbered；

The packet number of the first logic groups of the SET quantity that each packet in being grouped according to described at least two is included and the SSD that SET numberings described piece of request of calculating of the 2nd SET is mapped spatially.

With reference to one side face, and/or the first possible implementation, in second of possible implementation, the call number that the first SET that described piece of request is mapped in first logic groups is obtained by mapping function, including：

According to start offset of the described piece of request on the disk space, the input value of the mapping function is obtained；By the input value to parameter preset modulus, the call number for the first SET that described piece of request is mapped in first logic groups is obtained.

With reference to one side face, and/or the first possible implementation, and/or second of possible implementation, it is described that described piece of request is write into the first SET in the third possible implementation, including：

According to the packet number of first logic groups and the call number of the first SET, SET numberings of the first SET in the SSD spaces is determined；

According to SET numberings of the first SET in the SSD spaces, described piece of request is write described first

SET。

On the other hand there is provided a kind of device for accessing solid state hard disc space, described device includes：

Division unit, for the solid-state hard disk SSD space comprising some set of blocks SET to be carried out into decile, obtain at least two to be grouped, wherein there is the SET in each packet the SET with same offset in identical call number, at least two packet to belong to same logic groups； Map unit, for asking to be mapped to the first logic groups of the SSD that the division unit divided spatially by the block conducted interviews to disk space；

Acquiring unit, the call number for obtaining the first SET that described piece of request is mapped in the first logic groups that the map unit is mapped by mapping function；

Writing unit, for described piece of request to be write into first SET corresponding with the call number acquired in the acquiring unit.

With reference to above-mentioned another aspect, in the first possible implementation, the map unit includes：Start offset obtains subelement, and the block conducted interviews for obtaining to the disk space asks the start offset on the disk space；

SET numbering computation subunits, the SET that described piece of request corresponding 2nd SET on the disk space is calculated for obtaining the start offset that subelement is obtained according to the start offset is numbered；

Packet number computation subunit, for being grouped according to described at least two in the 2nd SET SET numberings that are calculated of the SET quantity that is included of each packet and the SET numberings computation subunit calculate the packet numbers of the first logic groups of the SSD that described piece of request mapped spatially.

With reference to above-mentioned another aspect, and/or the first possible implementation, in second of possible implementation, the acquiring unit includes：

Input value obtains subelement, for the start offset according to described piece of request on the disk space, obtains the input value of the mapping function；

Call number obtains subelement, and the input value for obtaining subelement acquisition by the input value obtains the call number for the first SET that described piece of request is mapped in first logic groups to parameter preset modulus.

With reference to above-mentioned another aspect, and/or the first possible implementation, and/or second of possible implementation, in the third possible implementation, said write unit includes：

SET numbering determination subelements, for the packet number according to first logic groups and the call number of the first SET, determine SET numberings of the first SET in the SSD spaces；

Block request write-in subelement, for the SET numberings according to the first SET determined by the SET numberings determination subelement, the first SET is write by described piece of request.

Another aspect includes there is provided a kind of system for accessing solid state hard disc space, the system：Disk, solid-state hard disk SSD and controller,

The controller, for the SSD spaces comprising some SET to be carried out into decile, at least two are obtained to be grouped, SET in wherein each packet has identical call number, the SET with same offset belongs to same logic groups at least two packet,, will be described when receiving the block conducted interviews to the disk space of the disk request Block request is mapped to the first logic groups of the SSD of the SSD spatially, the call number for the first SET that described piece of request is mapped in first logic groups is obtained by mapping function, and described piece of request is write into the first SET.

With reference to above-mentioned another aspect, in the first possible implementation, the controller, the block conducted interviews specifically for obtaining to the disk space asks the start offset on the disk space, described piece of request corresponding 2nd SET on disk space SET numberings are calculated according to the start offset, the SET quantity and the SET numberings of the 2nd SET that each packet in being grouped according to described at least two is included calculate the packet number of the first logic groups of the SSD that described piece of request mapped spatially.

With reference to above-mentioned another aspect, and/or the first possible implementation, in second of possible implementation, the controller, specifically for the start offset according to described piece of request on the disk space, the input value of the mapping function is obtained, by the input value to parameter preset modulus, the call number for the first SET that described piece of request is mapped in first logic groups is obtained.

With reference to above-mentioned another aspect, and/or the first possible implementation, and/or second of possible implementation, in the third possible implementation, the controller, specifically for the packet number according to first logic groups and the call number of the first SET, determines SET numberings of the first SET in the SSD spaces, numbered according to the SET of the first SET, described piece of request is write into the first SET.

In the embodiment of the present invention, SSD spaces comprising some SET are subjected to decile, at least two are obtained to be grouped, SET in wherein each packet has identical call number, the SET with same offset belongs to same logic groups at least two packets, when receiving the block conducted interviews to disk space request, block request is mapped to the first logic groups of SSD spatially, the call number for the first SET that block request is mapped in the first logic groups is obtained by mapping function, by the first SET of block request write-in.SSD spaces are grouped by the embodiment of the present invention, so as to which block request is mapped in some logic groups after dividing, due to including the SET consistent with the quantity of packet in each logic groups, the uniform access in SSD spaces is thus achieved, SSD buffer efficiency and service efficiency is improved.Brief description of the drawings is in order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, the required accompanying drawing used in embodiment or description of the prior art will be briefly described below, apparently, drawings in the following description are only some embodiments of the present invention, for those of ordinary skill in the art, without having to pay creative labor, other accompanying drawings can also be obtained according to these accompanying drawings.

Figure 1A accesses one embodiment flow chart of the method in solid state hard disc space for the present invention；

Figure 1B is mapping relations schematic diagram in the prior art between disk and SSD； Fig. 1 C are the schematic diagram that is grouped to SSD spaces in the embodiment of the present invention；

Fig. 2A accesses another embodiment flow chart of the method in solid state hard disc space for the present invention；

Fig. 2 B are an application example schematic diagram for combining Fig. 2A embodiments；

Fig. 3 accesses the embodiment block diagram of the device in solid state hard disc space for the present invention；

Fig. 4 accesses the embodiment block diagram of the system in solid state hard disc space for the present invention.Embodiment following examples of the present invention provide the method for accessing solid state hard disc space, apparatus and system.

In order that those skilled in the art more fully understand the technical scheme in the embodiment of the present invention, and enable the above-mentioned purpose of the embodiment of the present invention, feature and advantage more obvious understandable, technical scheme in the embodiment of the present invention is described in further detail below in conjunction with the accompanying drawings.

It is one embodiment flow chart for the method that the present invention accesses solid state hard disc space referring to Figure 1A：Step 101:The block conducted interviews to disk space request is mapped to the first logic groups of SSD spatially.The characteristics of according to disk and solid-state hard disk SSD each, the space of disk is typically larger than SSD, and SSD has a good access performance, thus can using SSD as disk caching, to accelerate user to the access speed of disk.In the present embodiment before SSD spaces are accessed, SSD spaces comprising some set of blocks SET can be subjected to decile, at least two are obtained to be grouped, there is SET in wherein each packet the SET with same offset in identical call number, at least two packets to belong to same logic groups.It should be noted that, it is above-mentioned that SSD spaces divide without being carried out when accessing SSD spaces each time, it can be performed once only at initial access SSD spaces, division result when subsequently access SSD spaces can be based on initial access each time is conducted interviews, and this present embodiment is not limited.

It is the mapping relations schematic diagram in the prior art between disk and SSD referring to Figure 1B：

Disk space is divided into M according to SSD capacity（M is natural number）Disk subspace, SSD spaces are divided into N, and (N is natural number）Individual SET, N number of SET is accordingly divided into for each disk subspace according to the dividing mode in SSD spaces.As schemed shown in IB, the numbering that the numbering for N number of SET that wherein SSD is included is the N X M SET from 0 to N-l, included on disk is from 0 to N X (M-1).Wherein, i-th of SET on direct mapping mode, i.e., each disk subspace is used to both map on i-th of the SET of SSD spatially between disk and SSD（I span is 1 to N), due to having M disk subspace, therefore equivalent to the SET of M SET correspondences SSD spatially on disk subspace.

It is the schematic diagram being grouped to SSD spaces in the embodiment of the present invention referring to Fig. 1 C：

In the embodiment of the present invention, N number of SET in SSD spaces is subjected to K deciles, K packet, Mei Gefen is obtained Comprising N/K SET in group, wherein N/K SET in each packet has identical call number, as shown in Figure 1 C, the call number of K packet is respectively 0 to K-1;Wherein, the SET for having same offset in K packet belongs to same logic groups, and as shown in Figure 1 C, the packet number of logic groups is respectively 0 to N/K-l.

In this step, optionally, obtain the block conducted interviews to disk space and ask the start offset on disk space, block request the 2nd SET corresponding on disk space SET numberings are calculated according to start offset, SET quantity and the 2nd SET SET numberings calculation block that each packet in being grouped according at least two is included ask the packet number of the first logic groups of mapped SSD spatially.

Step 102:The call number for the first SET that block request is mapped in the first logic groups is obtained by mapping function.

Optionally, the start offset on disk space is asked according to block, obtains the input value of mapping function, by the input value to parameter preset modulus, obtain the call number for the first SET that block request is mapped in the first logic groups.

Optionally, mapping function can be specially hash function；Now, input value can include：Block asks the start offset on disk space, or, the random value for asking block the start offset on disk space to use pseudo-random function to generate.

Step 103:By the first SET of block request write-in.

Optionally, according to the packet number of the first logic groups and the first SET call number, SET numberings of the first SET in SSD spaces is determined, is numbered according to SETs of the first SET in SSD spaces, by the first SET of block request write-in.

As seen from the above-described embodiment, SSD spaces are grouped by the embodiment, so that block request is mapped in some logic groups after dividing, due to including the SET consistent with the quantity of packet in each logic groups, are thus achieved

The uniform access in SSD spaces, improves SSD buffer efficiency and service efficiency.It is another embodiment flow chart for the method that the present invention accesses solid state hard disc space referring to Fig. 2A, the embodiment is described with reference to a specific application example：

Step 201:Obtain the block conducted interviews to disk space and ask the start offset on disk space.

The characteristics of according to disk and solid-state hard disk SSD each, the space of disk is typically larger than SSD, and SSD has a good access performance, thus can using SSD as disk caching, to accelerate user to the access speed of disk.In the present embodiment before access SSD spaces are performed, SSD spaces comprising some set of blocks SET can be subjected to decile, at least two are obtained to be grouped, there is SET in wherein each packet the SET with same offset in identical call number, at least two packets to belong to same logic groups.It should be noted that above-mentioned carry out dividing without being carried out when accessing SSD spaces each time to SSD spaces, it can be performed once only at initial access SSD spaces, it is follow-up every Division result when once access SSD spaces can be based on initial access is conducted interviews, and this present embodiment is not limited.

In the present embodiment, the mapping relations between disk and SSD, and the description being grouped to SSD spaces are consistent with the description of the embodiment shown in earlier figures 1, will not be repeated here.

In the present embodiment, a kind of application example schematic diagram with reference to shown in Fig. 2 B, it is assumed that disk space is 40G, SSD spaces are that each SET in 10G, and SSD spaces is made up of 512 blocks, and each block size is 4KB.It is then corresponding, disk space is divided into M=40G/10G=4 disk subspace according to the size in SSD spaces, each SET sizes are 512 X 4KB=2M again, shellfish U SSD spaces are divided into N=10G/2M=5000 SET, and disk space is accordingly divided into 40G/2M=20000 SET.In the present embodiment, it is assumed that SSD spaces are carried out into five deciles, obtain five and be grouped, be i.e. K=5, then the size that the actual mapping space comprising Ν/Κ=5000/5=1000 SET, i.e. SSD is 1000 SET in each packet.Wherein, the call number of five packets is followed successively by 0,1,2,3,4；The packet number of 1000 logic groups is followed successively by 0 to 999.

The block generally conducted interviews to disk space asks the start offset on disk space to be indicated with the skew of its initial sector.In this step, as previously described, it is assumed that each SET size is 2M, and the size of each sector is 512Kb, then each SET includes 2M/512KB=4096 sector.Assuming that the initial sector skew of the block request conducted interviews to disk space is respectively 12288,12296,12304.

Step 202:The 2nd SET SET numberings according to corresponding to asking on disk space start offset calculation block.The SET on disk space after initial sector skew of the block request on disk space is obtained, it is necessary to according to belonging to asking the initial sector calculations of offset block.

Because each SET includes 4096 sectors, therefore the SET on the corresponding disk space of each block request is respectively, 12288/4096=3,12296/4096=3,12304/4096=3, wherein, "/" represents to remove and rounded, the 3rd SET belonged on disk space, the SET numberings on disk space are 2 accordingly.

Step 203:SET quantity and the 2nd SET SET numberings calculation block that each packet in being grouped according at least two is included ask the packet number of the first logic groups of mapped SSD spatially.

It is 2 according to SET numbering of the obtained three blocks request on disk space is calculated in step 203 comprising 1000 SET because SSD is each grouped interior, therefore the packet number of correspondence SSD logic groups（Base) it is：2%1000=2 (% is represented except taking the remainder）, i.e., three blocks requests are same to correspond to SSD spatially packet numbers（Base the SET in the) logic groups for being 2, i.e. the 3rd logic groups of SSD spatially.

Step 204:Start offset on disk space is asked according to block, the input value of mapping function is obtained.The mapping function used is assumed in the present embodiment for hash function, and the input value of hash function asks the initial sector skew on disk space using block, i.e., the input value of three block requests is respectively 12288,12296 and 12304. Step 205:By input value to parameter preset modulus, the call number for the first SET that block request is mapped in the first logic groups is obtained.

In the present embodiment, the decile number of times modulus according to SSD spaces is offset to initial sector of each piece of request on disk space using hash function, is used as this block to ask the call number in the logic groups belonging to it.

With reference to Fig. 2 B, with initial sector skew 12288,12296 and 12304 of three block requests on disk space respectively to 5 modulus, correspondence packet number is respectively for the call number (index) in 2 logical groups：12288%5- 1=2, the block request of 12296%5-1=0,12304%5-1=3, i.e., three is respectively mapped to packet number（Base) in the logic groups for being 2, call number（Index) be respectively 2,0 and 3 SET on.

Step 206:According to the packet number of the first logic groups and the first SET call number, SET numberings of the first SET in SSD spaces is determined.

According to abovementioned steps, the packet number of each piece of the mapped logic groups of request is obtained（), and the call number in each logic groups base（), index numbering of three block requests in the whole SSD SET spatially mapped is now calculated according to equation below（Real set ):

Real set=index X N/K+base, wherein, K=5, N=5000, base=2_;

For first block request, according to above-mentioned formula, its SET numbering spatially mapped in whole SSD（Real set) be： 2 X 5000/5+2=2000+2=2002;

Similarly, asked for second block, its SET numbering spatially mapped in whole SSD（Real set) be： 0 X 5000/5+2=2；For the 3rd block request, its SET numbering spatially mapped in whole SSD（Real set) be： 3 X 5000/5+2=3002;

It follows that three block requests will be mapped to SSD spatially to number the SET for being 2 simultaneously according to prior art

On 3；And according to the embodiment of the present invention, then ask above three block to be respectively mapped on 3 SET that SET numberings are 2002,2 and 3002.Therefore, using the embodiment of the present invention, when occurring data hot spot region on disk, then being mapped to the block request in the whole spaces of SSD will tend to be balanced.

Step 207:According to SET numberings of the first SET in SSD spaces, by the first SET of block request write-in.As seen from the above-described embodiment, SSD spaces are grouped by the embodiment, so as to which block request is mapped in some logic groups after dividing, due to including the SET consistent with the quantity of packet in each logic groups, the uniform access in SSD spaces is thus achieved, SSD buffer efficiency and service efficiency is improved.Corresponding with the embodiment of the method that the present invention accesses solid state hard disc space, present invention also offers the embodiment for the apparatus and system for accessing solid state hard disc space.

It is the embodiment block diagram for the device that the present invention accesses solid state hard disc space referring to Fig. 3： The device includes：Division unit 310, map unit 320, acquiring unit 330 and writing unit 340.Wherein, division unit 310, for the solid-state hard disk SSD space comprising some set of blocks SET to be carried out into decile, at least two are obtained to be grouped, there is SET in wherein described each packet the SET with same offset in identical call number, at least two packet to belong to same logic groups；

Map unit 320, for asking to be mapped to the first logic groups of the SSD that the division unit 310 divided spatially by the block conducted interviews to disk space；

Acquiring unit 330, the call number for obtaining the first SET that described piece of request is mapped in the first logic groups that the map unit 320 is mapped by mapping function；

Writing unit 340, for described piece of request to be write into first SET corresponding with the call number acquired in the acquiring unit 330.

Optionally, the map unit 320 can include（Not shown in Fig. 3）：

Start offset obtains subelement, and the block conducted interviews for obtaining to the disk space asks the start offset on the disk space；

Optionally, the acquiring unit 330 can include（Not shown in Fig. 7）：

Input value obtains subelement, for the start offset according to described piece of request on the disk space, obtains the input value of the mapping function；Optionally, the mapping function can be specially hash function；The input value can include：Start offset of the described piece of request on the disk space, or, the random value that pseudo-random function is generated is used to start offset of the described piece of request on the disk space；

Optionally, said write unit 340 can include（Not shown in Fig. 3）：

Block request write-in subelement, for the SET numberings according to the first SET determined by the SET numberings determination subelement, the first SET is write by described piece of request. It is the embodiment block diagram for the system that the present invention accesses solid state hard disc space referring to Fig. 4：

The system includes：Disk 410, solid-state hard disk SSD 420 and controller 430.

Wherein, the controller 410, for the SSD spaces comprising some set of blocks SET to be carried out into decile, at least two are obtained to be grouped, SET in wherein described each packet has identical call number, the SET with same offset belongs to same logic groups at least two packet, when receiving the block conducted interviews to the disk space of the disk request, described piece of request is mapped to the first logic groups of the SSD of the SSD spatially, the call number for the first SET that described piece of request is mapped in first logic groups is obtained by mapping function, and described piece of request is write into the first SET.

Optionally, the controller 430, the start offset on the disk space can be asked specifically for obtaining the block conducted interviews to the disk space, described piece of request corresponding 2nd SET on disk space SET numberings are calculated according to the start offset, the SET quantity and the SET numberings of the 2nd SET that each packet in being grouped according to described at least two is included calculate the packet number of the first logic groups of the SSD that described piece of request mapped spatially.

Optionally, the controller 430, can be specifically for the start offset according to described piece of request on the disk space, obtain the input value of the mapping function, by the input value to parameter preset modulus, the call number for the first SET that described piece of request is mapped in first logic groups is obtained.

Optionally, the controller 430, can be specifically for the packet number according to first logic groups and the call number of the first SET, determine SET numberings of the first SET in the SSD spaces, numbered according to the SET of the first SET, described piece of request is write into the first SET.As seen from the above-described embodiment, SSD spaces comprising some SET are subjected to decile, at least two are obtained to be grouped, SET in wherein each packet has identical call number, the SET with same offset belongs to same logic groups at least two packet, when receiving the block conducted interviews to disk space request, block request is mapped to the first logic groups of SSD spatially, the call number for the first SET that block request is mapped in the first logic groups is obtained by mapping function, by the first SET of block request write-in.SSD spaces are grouped by the embodiment of the present invention, so as to which block request is mapped in some logic groups after dividing, due to including the SET consistent with the quantity of packet in each logic groups, the uniform access in SSD spaces is thus achieved, SSD buffer efficiency and service efficiency is improved.

Those skilled in the art can be understood that the technology in the embodiment of the present invention can add the mode of required general hardware platform to realize by software.Understood based on such, the part that technical scheme in the embodiment of the present invention substantially contributes to prior art in other words can be embodied in the form of software product, the computer software product can be stored in storage medium, such as R0M/RAM, magnetic disc, CD, including some instructions are to cause one Computer equipment（Can be personal computer, server, or network equipment etc.）Perform the method described in some parts of each embodiment of the invention or embodiment.

Each embodiment in this specification is described by the way of progressive, and identical similar part is mutually referring to what each embodiment was stressed is the difference with other embodiment between each embodiment.For system embodiment, because it is substantially similar to embodiment of the method, so description is fairly simple, the relevent part can refer to the partial explaination of embodiments of method.

The embodiments of the present invention described above are not intended to limit the scope of the present invention.Any modifications, equivalent substitutions and improvements made within the spirit and principles in the present invention etc., should be included in the scope of the protection.

Claims

Claim

1st, a kind of method for accessing solid state hard disc space, it is characterized in that, the solid-state hard disk SSD space includes at least two packets, it is each to be grouped into the obtained packet of some set of blocks SET included in the SSD spaces progress etc. point, SET in wherein described each packet has identical call number, the SET with same offset belongs to same logic groups at least two packet, and methods described includes：

The block conducted interviews to disk space request is mapped to the first logic groups of the SSD spatially；The call number for the first SET that described piece of request is mapped in first logic groups is obtained by mapping function；

Described piece of request is write into the first SET.

2nd, according to the method described in claim 1, it is characterised in that it is described by the block conducted interviews to disk space request be mapped to the first logic groups of the SSD spatially, including：

Obtain the block conducted interviews to the disk space and ask the start offset on the disk space；The SET that described piece of request corresponding 2nd SET on the disk space is calculated according to the start offset is numbered；

The packet number of the first logic groups of the SET quantity that each packet in being grouped according to described at least two is included and the SSD that SET numberings described piece of request of calculating of the 2nd SET is mapped spatially.

3rd, method according to claim 1 or 2, it is characterised in that the call number that the first SET that described piece of request is mapped in first logic groups is obtained by mapping function, including：

According to start offset of the described piece of request on the disk space, the input value of the mapping function is obtained；

By the input value to parameter preset modulus, the call number for the first SET that described piece of request is mapped in first logic groups is obtained.

4th, method according to claim 3, it is characterised in that the mapping function is specially hash function；

The input value includes：Start offset of the described piece of request on the disk space, or, the random value that pseudo-random function is generated is used to start offset of the described piece of request on the disk space.

5th, the method according to Claims 1-4 any one, it is characterised in that described by described piece Request write-in the first SET, including：

According to the packet number of first logic groups and the call number of the first SET, SET numberings of the first SET in the SSD spaces is determined；

According to SET numberings of the first SET in the SSD spaces, described piece of request is write into the first SET.

6th, a kind of device for accessing solid state hard disc space, it is characterised in that described device includes：Division unit, for the solid-state hard disk SSD space comprising some set of blocks SET to be carried out into decile, obtain at least two to be grouped, wherein there is the SET in each packet the SET with same offset in identical call number, at least two packet to belong to same logic groups；

Map unit, for asking to be mapped to the first logic groups of the SSD that the division unit divided spatially by the block conducted interviews to disk space；

Acquiring unit, the call number for obtaining the first SET that described piece of request is mapped in the first logic groups that the map unit is mapped by mapping function；

Writing unit, for described piece of request to be write into first SET corresponding with the call number acquired in the acquiring unit.

7th, device according to claim 6, it is characterised in that the map unit includes：Start offset obtains subelement, and the block conducted interviews for obtaining to the disk space asks the start offset on the disk space；

SET numbering computation subunits, the SET that described piece of request corresponding 2nd SET on the disk space is calculated for obtaining the start offset that subelement is obtained according to the start offset is numbered；

Packet number computation subunit, for being grouped according to described at least two in the 2nd SET SET numberings that are calculated of the SET quantity that is included of each packet and the SET numberings computation subunit calculate the packet numbers of the first logic groups of the SSD that described piece of request mapped spatially.

8th, the device according to claim 6 or 7, it is characterised in that the acquiring unit includes：Input value obtains subelement, for the start offset according to described piece of request on the disk space, obtains the input value of the mapping function；

Call number obtains subelement, and the input value for obtaining subelement acquisition by the input value obtains the call number for the first SET that described piece of request is mapped in first logic groups to parameter preset modulus. 9th, device according to claim 8, it is characterised in that the mapping function is specially hash function；

The input value includes：Start offset of the described piece of request on the disk space, or, the random value that pseudo-random function is generated is used to start offset of the described piece of request on the disk space.

10th, the device according to claim 6 to 9 any one, it is characterised in that said write unit includes：

SET numbering determination subelements, for the packet number according to first logic groups and the call number of the first SET, determine SET numberings of the first SET in the SSD spaces；

Block request write-in subelement, for according to the first SET determined by the SET numberings determination subelement

SET is numbered, and described piece of request is write into the first SET.

11st, a kind of system for accessing solid state hard disc space, it is characterised in that the system includes：Disk, solid-state hard disk SSD and controller,

The controller, for the SSD spaces comprising some set of blocks SET to be carried out into decile, at least two are obtained to be grouped, SET in wherein described each packet has identical call number, the SET with same offset belongs to same logic groups at least two packet, when receiving the block conducted interviews to the disk space of the disk request, described piece of request is mapped to the first logic groups of the SSD of the SSD spatially, the call number for the first SET that described piece of request is mapped in first logic groups is obtained by mapping function, and described piece of request is write into the first SET.

12nd, system according to claim 11, it is characterised in that

The controller, the block conducted interviews specifically for obtaining to the disk space asks the start offset on the disk space, described piece of request corresponding 2nd SET on disk space SET numberings are calculated according to the start offset, the SET quantity and the SET numberings of the 2nd SET that each packet in being grouped according to described at least two is included calculate the packet number of the first logic groups of the SSD that described piece of request mapped spatially.

13rd, the system according to claim 11 or 12, it is characterised in that

The controller, specifically for the start offset according to described piece of request on the disk space, the input value of the mapping function is obtained, by the input value to parameter preset modulus, the call number for the first SET that described piece of request is mapped in first logic groups is obtained. 14th, the system according to claim 11 to 13 any one, it is characterized in that, the controller, specifically for the packet number according to first logic groups and the call number of the first SET, SET numberings of the first SET in the SSD spaces is determined, according to the first SET's

SET is numbered, and described piece of request is write into the first SET.