JP2000260128A - Recorder and disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk device capable of making access time definite redardlessly of a seek distance. SOLUTION: This disk device resets a track skew TrkSkew and a cylinder skew CylSkew for the unit of three tracks and in the head of a cylinder CYL for each unit of three tracks, the track skew TrkSkew and the cylinder skew CylSkew do not exist. Thus, a disk is formatted so that the physical leading position of CHUNK (block) can be equal on all disk surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus and a disk apparatus using a randomly accessible disk medium such as a hard disk (HDD), and more particularly to an improvement in a format of a disk medium on which data is to be recorded. is there.

[0002]

2. Description of the Related Art For example, in an editing site such as a broadcasting station, recently, in order to further improve editing efficiency,
As a medium for recording video data, a random accessible disk medium such as a hard disk (HDD) has been used instead of using a magnetic tape. In order to further improve access performance, not only one hard disk is used as a recording medium for performing so-called non-linear editing,
A disk array device configured by connecting D in an array is used.

As shown in FIGS. 7A and 7B, a hard disk used in an editing device or the like is constituted by a plurality of disk media DK arranged coaxially. Each disk medium DK has a plurality of tracks TRK.
Are formed. Each of these tracks TRK is divided into a plurality of sectors SCT. Each sector SC
The size of T is set to 512 bytes as an example. An area constituted by tracks located at the same diameter from the center of each disk medium DK is called a cylinder CYL. The cylinder CYL is sequentially numbered sequentially from the outer circumference toward the inner circumference. This cylinder number is used as a cylinder address. For example,
When 6000 tracks TRK from 0 to 5999 are formed on each disk medium, the cylinder number is:
CYL0 to CYL5999 are set.

[0004] When such a hard disk is applied to an editing device in a broadcasting station or the like as described above, the hard disk has A (Audio) / V (Video).
Data is recorded and read. In an A / V application (random real-time access) server using a hard disk, it is desirable that reading (reading) / writing (writing) to the hard disk can be completed in a predictable time. Further, in this type of server, for example, a unit for performing one read / write is determined by using a plurality of continuous sectors SCT over one track or over a plurality of tracks as one block, and access control to a disk medium is performed. ing. In addition, one block data (data to be recorded or data to be reproduced)
Is, for example, video data of one frame (image of a predetermined size).

FIG. 8 is a diagram showing an example of a format of a normal disk medium accessed in block units. This example shows a case where the number of read / write heads (hereinafter, simply referred to as heads) is 20, and the number of sectors per track at the position of the cylinder CYL0 is 199.
In this example, one block = 480 sectors, but one block extends over three tracks.

This disk medium has a track skew TrkSkew, which is a skew time in consideration of a moving time when a head switches, and a seek (SEEK) in consideration of a moving time when a cylinder is moved, mainly for so-called sequential reading. It is formatted in consideration of the cylinder skew CylSkew, which is the time, and the skew θskew which represents the offset between the head addresses of the tracks by an angle.

[0007]

However, as described above, in the normal format, sequential read is the main purpose, and therefore, a gap exists due to the track skew TrkSkew when the head switches and the cylinder skew CylSkew when the cylinder switches. Then, as shown in FIG. 8, the logical blocks are arranged, and as shown in FIG. 9, since the head of each track is shifted on a spiral, the disk medium of the above-mentioned normal format is used. In the disk device used, a rotation wait occurs when the head moves. Note that FIG.
The skew θskew refers to the angle difference between the heads of adjacent blocks on the disk medium DK in the circumferential direction as viewed from the center of the disk.

[0008] Actually, since the disk surfaces are further shifted relative to each other, the chunk (CHUNK) of the disk surface is selected depending on the selected chunk (CHUNK).
Completely changes the start position. Note that CHUNK is equivalent to a block, and is a unit for one read / write. For example, when 1 CHUNK = 480 sectors, one read / write command reads / writes data for 480 sectors. Means to do.

Hereinafter, the rotation waiting in the disk device will be considered in more detail with reference to the drawings.

As described above, in an A / V application (random real-time access) server using a hard disk, it is desirable that read / write to the hard disk be completed in a predictable time. However, in an actual hard disk, when data at a certain address is read, an error corresponding to the maximum Trot time (rotation waiting) occurs every time depending on the position of the immediately preceding head and the physical location of the disk. For example, if you want to perform a continuous read,
After the transfer of the first read data is completed, a seek operation is performed to execute a second read command that has been queued in advance, and a target sector is reached. In other words, whether it is in time or not is a matter of probability, and it is impossible with current methods to control it.

When a continuous read command is issued, the hard disk can express the time TI / O from the start of command execution to the end of transfer by the following equation.
However, this is a case where a logical address that sequentially moves from the outer circumference to the inner circumference is given so that the back seek does not occur.

[0012]

## EQU1 ## TI / O = Tseek + Trot + Tread

[0013] Here, Tseek is the time to seek to a certain point, and Trot is the head chunk (CH) after seeking.
The rotation waiting time (0 to 1 rotation time) until the data reaches UNK), and Tread represents the time during which data is transferred from the disk to the internal buffer.

FIG. 10 shows the difference between the command immediately before the data transfer completion time after issuing a command when a continuous read is performed at a fixed number of blocks (eg, 480 sectors) in one read. Is the Y-axis, the physical cylinder position difference between the two commands (SEEK
LENGTH) on the X axis. FIG. 11 shows a result similar to that of FIG. 10 except that, in one read operation, random continuous read operation is performed with a variable number of blocks that keeps the time Tread constant. Further, 1 CHUNK = 2.8 rounds in FIG. 11 indicates the number of sectors / track TRK * determined for each certain zone.
This means that the number of sectors corresponding to 2.8 times is specified.

In other words, FIGS. 10 and 11 show a case where a group of logical addresses arranged in ascending order (approximately 14) is issued continuously to the hard disk so as not to cause a back seek. And the time from when the hard disk receives the processing of the command until the transfer is completed (Y-axis: ms). Actually, the difference between the data transfer completion times is measured. The X axis represents the difference between the physical cylinder positions of two consecutive commands.

That is, if a seek time (Tseek) for moving to the next point is added, a time depending on the seek distance occurs in addition to a time (Tread) for transferring data from the disk. The two solid lines indicated by and in the figure are the theoretical formula (lower side) and the rotation waiting time Trot (Worst = 8.3) when 1 CHUNK = 2.8 rounds is fixed.
3 ms (in the case of this disc). In the drawing, the back seek portion is omitted.

As is well known, the hard disk differs in the number of sectors per track between the outer circumference and the inner circumference. Therefore, when 1CHUNK = 480 sectors is specified, the recording time is longer at the inner circumference because the recording density is low at the inner circumference, during which data is transferred from the internal disk.
On the other hand, on the outer circumference, the time Tread becomes small, and depending on the place where the data is read, the time from issuing the command to ending the transfer may vary due to factors other than the rotation wait. The variation in FIG. 10 means that phenomenon.

When 1 CHUNK = 2.8 turns, the transfer time Tread is constant. Since the time Tread is fixed for both the inner circumference and the outer circumference, it is natural that
The transfer amount differs between the inner and outer circumferences.

In this case, variation occurs in the range of Trot. However, for an access time of 30 to 40 ms, the error of 8.33 ms (20 to 25%) is large.

Therefore, in the normal format, as described above, the sequential read is the main purpose.
Track skew TrkSk when head switches
ew and cylinder skew C when the cylinder is switched
Since a gap exists due to ylSkew, in a disk device using a disk medium of a normal format, a rotation wait occurs when the head is moved, and the access time is determined by the next access location or the current position of the head. Affected, it is not possible to accurately predict the time to complete the data transfer when reading. As a result, variations occur, and when the average data transfer rate of the disk is to be utilized to the maximum, performance is significantly reduced. As a result, it is necessary to take measures to increase the number of disks or increase the data transfer speed.

FIG. 12 is a histogram showing the time from issuing a command at the time of reading data at random with the data size to be read at one time being constant until the completion of data transfer. As can be seen from FIG. 12, there is variation in the time from issuing a command at the time of reading data at a fixed data size to completion of data transfer.

As described above, the hard disk is a disk having many unstable elements, and it is difficult to operate it as theoretically. As shown in FIG. 10, the rotation waiting time T
It is considered sufficient to have a margin of about rot, but for example, if data is transferred within 32 to 40 ms after issuing a command, there will be an error of as much as 20%. It is good if this is one, but usually it is necessary to issue commands continuously in order to obtain performance.
The error is too large to predict the transfer end time of the 0th command. In other words, in order to absorb this error, some other means, such as preparing an extra buffer (memory), increasing the number of disks, or using compressed video data to lower the transfer rate, is required. This leads to higher costs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a recording apparatus and a disk apparatus capable of keeping an access time constant regardless of a seek distance.

[0024]

In order to achieve the above object, the present invention provides a disk medium in which tracks on which data is recorded are arranged coaxially, rotated at a predetermined number of revolutions, and A recording apparatus in which data to be accessed at a time is performed in a block unit having a predetermined amount over one or a plurality of tracks. The format is such that the proper start positions are substantially the same on each disk surface.

According to the present invention, in each block, when a track is switched, a track skew corresponding to a delay time when the track is switched is shifted from a physical head position of the block by an amount corresponding to the number of tracks to be switched. The continuous data is recorded at the position where the track skew is reset and the head position of the switching block is located at the position where the track skew is reset every time the block is switched.

In the present invention, the track of each disk medium is divided into a plurality of sectors, and the block is constituted by a plurality of continuous sectors capable of suppressing occurrence of a rotation wait.

In the present invention, the block size is set according to the number of tracks in the cylinder.
Alternatively, the block size is set according to the number of tracks and the number of sectors in the cylinder.

According to the present invention, there is also provided a disk apparatus in which data to be accessed at one time is performed in a block unit having a predetermined amount over one or a plurality of tracks, wherein a track on which data is recorded is formed. Disk media are arranged coaxially and rotated at a predetermined number of revolutions, each disk media spans a track in which blocks are continuous, and
A disk assembly portion in which the physical head positions of the blocks are formatted so as to be substantially the same on each disk surface, and a plurality of disk assembly portions provided respectively corresponding to the track forming surfaces of each disk medium of the disk assembly portion. A head assembly unit having a head, a head drive system for controlling the movement of each head of the head assembly unit in the radial direction of each disk medium of the disk assembly unit and positioning the head at a desired position, and data addressed by the addressed head. And a circuit for reading data from a predetermined track by a head that has written or addressed a predetermined track.

According to the present invention, since the physical head position of a block is the same on all disk surfaces, if the cylinder position is determined, the access time can be predicted. In addition, by setting the block within a predetermined number of tracks and selecting the number of sectors where rotation wait does not occur, from the end of the block, which was impossible with the normal format,
At the distance of the beginning of the next block of points, it can be predicted whether a rotation wait will occur. Therefore, there is no time uncertainty in the access to the disk medium, and the access time is constant and the response time is constant in a certain range regardless of the seek distance.

[0030]

FIG. 1 is a system configuration diagram of a hard disk drive to which a recording apparatus according to the present invention is applied.

As shown in FIG. 1, the present hard disk drive 10 includes a disk assembly unit 11, a head assembly unit 12, a spindle motor 13, a spindle motor driver 14, a voice coil motor (VCM) 15,
CM driver 16, digital / analog converter (DAC) 17, read / write (R / W) circuit 18,
An AGC (Auto Gain Control) amplifier 19, a signal detection circuit 20, a level detection circuit 21, an analog / digital converter (ADC) 22, a controller 23, and an interface S with a host computer (not shown).
It is constituted by a CSI (ANSI Small Computer System Interface) 24.

In the disk assembly section 11, ten disk media DK1 to DK10 are coaxially arranged at predetermined intervals. Each disk medium DK1 to DK10
Are formed with a plurality of tracks TRK. Each of these tracks TRK is divided into a plurality of sectors SCT. The size of each sector SCT is set to 512 bytes. Then, each of the disk media DK1 to DK
An area constituted by tracks located at the same diameter from the center of the cylinder 10 is a cylinder CYL. This cylinder CYL
Are sequentially numbered sequentially from the outer circumference toward the inner circumference. This cylinder number is used as a cylinder address. For example, each disk medium DK1-D
When 6000 tracks TRK from 0 to 5999 are formed in K10, the cylinder number is CYL0.
To CYL5999. The disk assembly unit 11 is rotated at a rotation speed of, for example, 7200 rpm by a spindle motor 13 driven by a spindle motor driver 14 receiving a control signal from the controller 23.

Then, in the head assembly 12, data reading from the track TRK or the track T on each surface is performed corresponding to the upper and lower surfaces of the ten disk media DK1 to DK10 of the disk assembly 11 respectively.
Heads (read / write heads) HD0 to HD19 for writing data to the RK are provided, respectively.
The movement of the head assembly 12 is controlled by a head drive system. Specifically, the disk medium DK is driven by the VCM 15 driven by the VCM driver 16 which has received a control signal from the controller 23 via the DAC 17.
1 to DK10 in the radial direction, and the head HD0 is controlled.
~ HD19 is a predetermined track TRK based on address specification
Will be positioned.

The upper surface of the disk medium DK1 is the head HD0
Access (including read / write seek operation)
The lower surface is accessed by the head HD1. Similarly, the upper surface of the disk medium DK2 is accessed by the head HD2, the lower surface is accessed by the head HD3, the upper surface of the disk medium DK3 is accessed by the head HD4, and the lower surface is accessed by the head HD5.
The upper surface of the disk medium DK4 is accessed by the head HD6, the lower surface is accessed by the head HD7, the upper surface of the disk medium DK5 is accessed by the head HD8, the lower surface is accessed by the head HD9, and the upper surface of the disk medium DK6 is accessed by the head HD10. The lower surface is accessed by the head HD11, the upper surface of the disk medium DK7 is accessed by the head HD12, the lower surface is accessed by the head HD13, the upper surface of the disk medium DK8 is accessed by the head HD14, and the lower surface is accessed by the head HD15. The upper surface of the disk medium DK9 is accessed by the head HD16, the lower surface is accessed by the head HD17, the upper surface of the disk medium DK10 is accessed by the head HD18, and the lower surface is the head. It is accessed by the D19.

As described above, each of the disk media DK1 to DK1 of the disk assembly unit 11 accessed by each of the heads HD0 to HD19 of the head assembly unit 12.
0 is formatted as shown in FIG. 2 to enable random access in block units.

That is, the block size for A / V use is random access, and is basically a fixed block size. Track skew TrkSkew for each track that uses this fixed block size as one unit
Formatted to reset The present embodiment shows a case where the number of sectors per track at the position of the cylinder CYL0 is 199, and is an example where 1 block = 480 sectors. In this case, one block extends over three tracks. Therefore, in the format shown in FIG. 2, the track skew T
Reset rkSkew.

That is, the physical head position of the CHUNK (block) is formatted so as to be the same on all disk surfaces.

It is needless to say that the block size may be changed to a block size corresponding to the number of sectors / tracks in the inner and outer zones because the number of sectors / tracks is different.

In order to realize the format structure as shown in FIG. 2, it is necessary to specially format the hard disk. Although it cannot be realized by a normal format command or the like, it can be realized by changing the physical format structure by firmware. The side controlling this, that is, the host computer (not shown),
If only the management of the head address of the HUNK and the number of sectors are considered, the others can be used in almost the same manner as usual. Translate logical addresses from physical addresses on the disk and use them.

In the hard disk device 10 shown in FIG. 1, write data sent from the host computer is input to the controller 23 via the SCSI 24, and the write current is supplied by the R / W circuit 18 to a desired position by the VCM 15 or the like. Is supplied to a desired head positioned at the position, and is written to a predetermined track. The read data read by the head is input to the R / W circuit 18, the level is adjusted by the AGC amplifier 19, detected by the signal detection circuit 20, and read by the controller 23, SC
The data is sent to the host computer through the SI 24.

Next, the disc format shown in FIG. 2 according to the present embodiment will be considered in relation to the formulas and drawings while comparing with the normal format shown in FIG.

The calculation formula for the format will be described below. Each item is defined as follows. Number of sectors per track (minimum): Smin Number of divisions of video data: Div Number of video data of one frame (sector): Vdata Number of video data per disk: Vdata / Div, and INT (n) is a decimal point If you truncate,
Number of used tracks per block / disk Vtra
ck is given by the following equation.

[0043]

## EQU2 ## Vtrack = ((INT) (Vdata / D
iv) / Smin) +1

Number of heads: HeadNum Delay time when moving cylinder: CylSkew Delay time when switching heads: TrkSkew Further, the minimum sector of each track is based on the head of the minimum sector number of CYL = 0, HD = 0. Assuming that the delay time of the position of the number: TrackOffset, the head position of each track in the disk format of FIG. 2, that is, the TrackO of each track
The ffset is as shown in FIG. FIG. 4 shows the head position of each track in the disk format of FIG. 8 as a comparison target.

Here, the remainder of dividing M by N is mod
When represented by (M, N), TrackOffset in the disc format of FIG. 2 is represented by the following equation.

[0046]

## EQU3 ## TrackOffset (cyl, head)
= TrkSkew * mod ((cyl * HeadNum
+ Head), Vtrack)

However, in the case of a block straddling a cylinder, the TrackOffset after straddling is 1 Trk.
It is replaced with 1 CylSkew instead of Skew. For example, after straddling the cylinder, mod (cy
TrackOffset is expressed by the following formula in a range before 1 * HeadNum + head, Vtrack) becomes zero.

[0048]

## EQU4 ## TrackOffset (cyl, head)
= TrkSkew * mod (cyl * HeadNum +
head, Vtrack) + CylSkew−TrkS
kew

On the other hand, TrackOffset in the normal disk format shown in FIG. 8 is expressed by the following equation.

[0050]

## EQU5 ## TrackOffset (cyl, head)
= TrkSkew * ((HeadNum-1) * cyl
+ Head) + CylSkew * cyl

The above equation is a general (approximate) equation.
In practice, more complex delay timings may occur. In addition, one frame of video data includes parity for error correction and RAID (Redundant Arrays of Ine
xpensive Disks).

As can be seen from FIGS. 3 and 4, and equations 3 and 4, the present disk format has CYL = 0 and HD = 0 compared to the normal disk format.
Of the minimum sector number of each track with reference to the head of the minimum sector number
t is greatly reduced. In addition, since the physical head position of CHUNK is the same on all disk surfaces, if the cylinder position is determined, the access time can be predicted.

In the present embodiment, the skew is reset every three tracks.
By setting the HUNK within 3 tracks and selecting the number of sectors in which the rotation wait does not occur, whether the rotation wait occurs at the distance from the end of the CHUNK to the start of the next point of the CHUNK, which was impossible with the normal format. You can predict whether.

Also, by specifying a block having a size such that rotation wait does not occur when seeking for each zone (constant time Tread), when continuous reading is performed, a fixed access time is set as shown in FIG. Can be realized. FIG. 6 shows this as a histogram graph.

If a command for continuously reading at a time is executed, the access interval (SEEK) is consequently obtained.
LENGTH), and the access time becomes almost constant. Furthermore, in order to sort commands to be executed successively, there is a method of moving from outside to inside like scanning, but in a normal format, a back seek occurs in the gap. Compared to this, the bidirectional scanning has the advantage that the performance does not change (no backseek occurs) even when moving from inside to outside, and the average transfer rate Can be raised.

Here, the performance of access to the disk will be considered. If random continuous read is to be performed, the time for one rotation of the disk: Trot The time to read one block: Tread seek time: Tseek Rotation wait: Twait From the end of reading the previous block to the end of reading the next block Time: Tdur In the case of a normal format, the time is expressed by the following equation as described above.

[0057]

Tdur = Tseek + Twait + Tread

In this case, the rotation waiting time Twait is 0
To Trot, and varies as shown in FIGS.

On the other hand, in the case of this format, if the rotation (constant) between the start position of the next block from the place where one block is continued is Tgap, Tseek <Tgap
Then, it becomes as follows.

[0060]

(7) Tdur = Tgap + Tread

When Tseek ≧ Tgap, the following is obtained.

[0062]

[Mathematical formula-see original document] Tdur = INT ((Tseek-Tgap)
/ Trot + 1) + Tread

However, mod ((Tseek-Tga
When p), Trot) is 0, Tdur = INT ((Tseek−Tgap) / Tro
t) + Tread, and a certain access is possible as shown in FIG.

As described above, according to the present embodiment, the track skew TrkSkew is reset every three tracks, and the time is negligible even if the cylinder skew CylSkew, which is a delay time during cylinder movement, occurs. Even if one block straddles two cylinders, the disk is formatted so that the physical head position of the CHUNK (block) is the same on all disk surfaces. Not only the access time is determined, but also the response time becomes constant, and an optimal hard disk drive for an A / V server can be realized.

In the above description, reading (reading) is described as an example, but it goes without saying that the present invention can be similarly applied to writing (writing). In this example, the track skew and the cylinder skew are reset to 0 every three tracks. However, it goes without saying that the present invention can be applied to each track or in other cases.

[0066]

As described above, according to the present invention,
Not only is the access time determined for the seek distance,
There is an advantage that the response time is constant. Therefore, read / write with a fixed access time like a memory is realized,
The worst value can be guaranteed without considering the rotation wait and the like.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a hard disk device to which a recording device according to the present invention is applied.

FIG. 2 is a diagram showing a disk format according to the present invention.

FIG. 3 shows a CYL =
0, HD = 0 Delay time Trac at the position of the minimum sector number for each track with reference to the head of the minimum sector number
It is a figure showing kOffset.

FIG. 4 shows a normal disk format CYL = 0, H
The delay time TrackOf of the position of the minimum sector number for each track with reference to the head of the minimum sector number of D = 0
It is a figure showing fset.

FIG. 5 shows a command immediately before the data transfer completion time after issuing a command when random continuous reading is performed with a fixed number of blocks in one reading for a disk having a format according to the present invention. FIG. 7 is a diagram showing a time difference between the two commands as a Y axis and a physical cylinder position difference (SEEK LENGTH) between two commands as an X axis.

FIG. 6 is a histogram showing the time from the issuance of a command at the time of random read to the completion of data transfer with the data size to be read at one time fixed for a disk of the format according to the present invention. FIG.

FIG. 7 is a diagram for explaining the relationship between cylinders, tracks, and sectors.

FIG. 8 is a diagram showing a format example of a normal disk medium accessed in block units.

FIG. 9 is a diagram for explaining a gap θgap and a skew θskew.

FIG. 10 shows 1 for a normal format disc.
In the first read, the number of blocks is fixed, and the time difference from the command immediately before the data transfer completion time after issuing the command at the time of performing the continuous read randomly is set as the Y axis,
Physical cylinder position difference between two commands (S
EEK LENGTH) on the X axis.

FIG. 11 shows an example of a normal format disc.
In the read times, the time difference from the command immediately before the data transfer completion time after issuing a command at the time of performing a continuous read at random with a variable number of blocks that keeps the time Tread constant is taken as the Y axis, Physical cylinder position difference between two commands (SEEK LENGT
It is the figure which expressed H) on the X-axis.

FIG. 12 is a diagram showing a histogram representing a time period from issuing a command at the time of reading data at random with a fixed data size to be read at a time until transfer of data is completed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Hard disk drive, 11 ... Disk assembly part, 12 ... Head assembly part, 13 ... Spindle motor, 14 ... Spindle motor driver, 15 ... Voice coil motor (VCM), 16 ... VCM driver, 1
7 Digital-to-analog converter (DAC), 18
... read / write (R / W) circuit, 19 ... AGC amplifier, 20 ... signal detection circuit, 21 ... level detection circuit, 22
... Analog to Digital Converter (ADC), 23 ...
Controller, 24 ... SCSI.

Claims (10)

[Claims] 1. A disk medium having tracks on which data is recorded is arranged coaxially, rotated at a predetermined rotation speed, and data to be accessed at one time extends over one or a plurality of tracks. A recording apparatus performed in units of blocks having a predetermined amount, wherein each of the disk media covers a track in which blocks are continuous, and a physical head position of each block is substantially the same on each disk surface. A recording device that has been formatted. 2. In each block, when a track is switched, a track skew corresponding to a delay time when the track is switched is shifted from a physical head position of the block by an amount corresponding to the number of tracks to be switched. 2. The recording apparatus according to claim 1, wherein continuous data is recorded, and each time a block is switched, the recording apparatus is formatted such that the head position of the switched block is located at a position where the track skew is reset. 3. The recording apparatus according to claim 1, wherein the track of each of the disk media is divided into a plurality of sectors, and the block is composed of a plurality of continuous sectors capable of suppressing occurrence of rotation waiting. 4. The recording apparatus according to claim 2, wherein the track of each of the disk media is divided into a plurality of sectors, and the block is composed of a plurality of continuous sectors capable of suppressing occurrence of a rotation wait. 5. The recording apparatus according to claim 1, wherein the block size is set according to the number of tracks in a cylinder. 6. The recording apparatus according to claim 2, wherein said block size is set according to the number of tracks in a cylinder. 7. The recording apparatus according to claim 1, wherein the block size is set according to the number of tracks and the number of sectors in a cylinder. 8. The recording apparatus according to claim 2, wherein said block size is set according to the number of tracks and the number of sectors in a cylinder. 9. A disk device in which data to be accessed at one time is performed in units of a block having a predetermined amount over one or a plurality of tracks, wherein a disk medium on which tracks on which data is recorded is formed is provided. Arranged on the same axis, rotated at a predetermined rotation speed,
A disk assembly section in which each disk medium is formatted so as to extend over a track in which blocks are continuous and the physical head position of each block is substantially the same on each disk surface; and each disk of the disk assembly section A head assembly section having a plurality of heads provided respectively corresponding to the track forming surfaces of the medium; and a desired position by controlling the movement of each head of the head assembly section in the radial direction of each disk medium of the disk assembly section. A disk drive, comprising: a head drive system for positioning a head; and a circuit for writing data to a predetermined track by an addressed head or reading data from a predetermined track by an addressed head. 10. In the disk assembly unit, in each block, when a track is switched, a track skew corresponding to a delay time when the track is switched is changed by a physical head position of the block by an amount corresponding to the number of tracks to be switched. 10. The recording apparatus according to claim 9, wherein the continuous data is recorded at a position shifted from the recording block, and the recording block is formatted such that, each time a block is switched, the head position of the switching block is located at a position where the track skew is reset.