view Documentation/cdrom/packet-writing.txt @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
line source
1 Getting started quick
2 ---------------------
4 - Select packet support in the block device section and UDF support in
5 the file system section.
7 - Compile and install kernel and modules, reboot.
9 - You need the udftools package (pktsetup, mkudffs, cdrwtool).
10 Download from http://sourceforge.net/projects/linux-udf/
12 - Grab a new CD-RW disc and format it (assuming CD-RW is hdc, substitute
13 as appropriate):
14 # cdrwtool -d /dev/hdc -q
16 - Setup your writer
17 # pktsetup dev_name /dev/hdc
19 - Now you can mount /dev/pktcdvd/dev_name and copy files to it. Enjoy!
20 # mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime
23 Packet writing for DVD-RW media
24 -------------------------------
26 DVD-RW discs can be written to much like CD-RW discs if they are in
27 the so called "restricted overwrite" mode. To put a disc in restricted
28 overwrite mode, run:
30 # dvd+rw-format /dev/hdc
32 You can then use the disc the same way you would use a CD-RW disc:
34 # pktsetup dev_name /dev/hdc
35 # mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime
38 Packet writing for DVD+RW media
39 -------------------------------
41 According to the DVD+RW specification, a drive supporting DVD+RW discs
42 shall implement "true random writes with 2KB granularity", which means
43 that it should be possible to put any filesystem with a block size >=
44 2KB on such a disc. For example, it should be possible to do:
46 # dvd+rw-format /dev/hdc (only needed if the disc has never
47 been formatted)
48 # mkudffs /dev/hdc
49 # mount /dev/hdc /cdrom -t udf -o rw,noatime
51 However, some drives don't follow the specification and expect the
52 host to perform aligned writes at 32KB boundaries. Other drives do
53 follow the specification, but suffer bad performance problems if the
54 writes are not 32KB aligned.
56 Both problems can be solved by using the pktcdvd driver, which always
57 generates aligned writes.
59 # dvd+rw-format /dev/hdc
60 # pktsetup dev_name /dev/hdc
61 # mkudffs /dev/pktcdvd/dev_name
62 # mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime
65 Packet writing for DVD-RAM media
66 --------------------------------
68 DVD-RAM discs are random writable, so using the pktcdvd driver is not
69 necessary. However, using the pktcdvd driver can improve performance
70 in the same way it does for DVD+RW media.
73 Notes
74 -----
76 - CD-RW media can usually not be overwritten more than about 1000
77 times, so to avoid unnecessary wear on the media, you should always
78 use the noatime mount option.
80 - Defect management (ie automatic remapping of bad sectors) has not
81 been implemented yet, so you are likely to get at least some
82 filesystem corruption if the disc wears out.
84 - Since the pktcdvd driver makes the disc appear as a regular block
85 device with a 2KB block size, you can put any filesystem you like on
86 the disc. For example, run:
88 # /sbin/mke2fs /dev/pktcdvd/dev_name
90 to create an ext2 filesystem on the disc.
93 Links
94 -----
96 See http://fy.chalmers.se/~appro/linux/DVD+RW/ for more information
97 about DVD writing.