dvd+rw求教

mrkissinger

根据Linux 2.6.11.6的文档（Documentation/cdrom/packet-writing.txt），DVD+RW应该可以当作一个普通的磁盘来用。

Packet writing for DVD+RW media
-------------------------------

According to the DVD+RW specification, a drive supporting DVD+RW discs
shall implement "true random writes with 2KB granularity", which means
that it should be possible to put any filesystem with a block size >=
2KB on such a disc. For example, it should be possible to do:

        # dvd+rw-format /dev/hdc   (only needed if the disc has never
                                    been formatted)
        # mkudffs /dev/hdc
        # mount /dev/hdc /cdrom -t udf -o rw,noatime

However, some drives don't follow the specification and expect the
host to perform aligned writes at 32KB boundaries. Other drives do
follow the specification, but suffer bad performance problems if the
writes are not 32KB aligned.

Both problems can be solved by using the pktcdvd driver, which always
generates aligned writes.

        # dvd+rw-format /dev/hdc
        # pktsetup dev_name /dev/hdc
        # mkudffs /dev/pktcdvd/dev_name
        # mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime

我在debian下用dvd+rw-format格式化后，光盘信息是这样。

Solomon:~# dvd+rw-mediainfo /dev/dvd
INQUIRY:                [BENQ    ][DVD DD DW1620   ][B7U9]
GET [CURRENT] CONFIGURATION:
Mounted Media:         1Ah, DVD+RW
Current Write Speed:   4.0x1385=5540KB/s
Write Speed #0:        4.0x1385=5540KB/s
Write Speed #1:        2.4x1385=3324KB/s
GET [CURRENT] PERFORMANCE:
Write Performance:     4.0x1385=5540KB/s@[0 -> 264671]
Speed Descriptor#0:    00/264671 R@1.7x1385=2394KB/s W@4.0x1385=5540KB/s
Speed Descriptor#1:    00/264671 R@1.7x1385=2394KB/s W@2.4x1385=3324KB/s
READ DVD STRUCTURE[#0h]:
Media Book Type:       01h, DVD-ROM book [revision 1]
Media ID:              INFODISC/A10
Legacy lead-out at:    264672*2KB=542048256
READ DISC INFORMATION:
Disc status:           complete
Number of Sessions:    1
State of Last Session: complete
Number of Tracks:      1
BG Format Status:      suspended
READ TRACK INFORMATION[#1]:
Track State:           complete
Track Start Address:   0*2KB
Free Blocks:           0*2KB
Track Size:            264672*2KB
FABRICATED TOC:
Track#1  :             17@0
Track#AA :             17@264672
Multi-session Info:    #1@0
READ CAPACITY:          2295104*2048=4700372992
Solomon:~#

但是当我mkfs的时候，无论是mkudffs还是直接mkfs.ext3，都只使用了信息中的lead-out部分，共500多M。

不知道怎么才能将剩余的4.2G用上？
请大虾指教。