From bee1df385fac40f9ea74c422adbecb236fe9917e Mon Sep 17 00:00:00 2001 From: Thomas Schmitt Date: Tue, 7 Jul 2020 15:57:09 +0000 Subject: [PATCH] --- QemuXorriso.md | 517 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 517 insertions(+) create mode 100644 QemuXorriso.md diff --git a/QemuXorriso.md b/QemuXorriso.md new file mode 100644 index 0000000..7544e69 --- /dev/null +++ b/QemuXorriso.md @@ -0,0 +1,517 @@ +This text describes how to set up a qemu virtual machine so that xorriso +on its guest GNU/Linux can operate a CD, DVD or BD recorder of the host +system. + +The options follow proposals of Paolo Bonzini on qemu-devel mailing list. +My compliments for his patient guidance. + +Basic knowledge about Debian and qemu was learned from +[GNU Hurd qemu page](http://www.gnu.org/s/hurd/hurd/running/qemu.html GNU Hurd qemu page). + +---------------------------------------------------------------------- +This start command works with `qemu-1.0-rc3`: + +``` + $ qemu \ + -enable-kvm \ + -nographic \ + -m 512 \ + -net nic,model=ne2k_pci \ + -net user,hostfwd=tcp::5557-:22 \ + -hda /dvdbuffer/i386-install.qemu \ + -drive file=/dev/sr0,if=none,id=scsicd,format=raw \ + -device virtio-blk-pci,drive=scsicd,logical_block_size=2048,physical_block_size=2048 \ + -cdrom .../some_image.iso +``` + +This start command works with `qemu-2.1.2`: + +``` + $ qemu \ + -enable-kvm \ + -nographic \ + -m 512 \ + -net nic,model=ne2k_pci \ + -net user,hostfwd=tcp::5557-:22 \ + -hda /dvdbuffer/i386-install.qemu \ + -cdrom .../some_image.iso \ + -drive file=/dev/sr0,index=2,if=virtio +``` + +With these setups of `-drive` and `-device` it is necessary to have a +medium in the drive, when qemu gets started. Else it will refuse. + +The guest system is accessible via ssh and scp at port 5557 of the +host system. + +`/dev/sr0` is the address of the DVD drive which is handed over to the +guest system. + +`.../some_image.iso` may be any readable file which shall serve as +virtual DVD-ROM. qemu is not happy without such a thing. + +`/dvdbuffer/i386-install.qemu` is the disk image, where the guest operating +system was installed by: +``` + $ qemu-img create /dvdbuffer/i386-install.qemu 8G + $ qemu \ + -enable-kvm \ + -m 512 \ + -net nic,model=ne2k_pci \ + -hda /dvdbuffer/i386-install.qemu \ + -cdrom debian-6.0.3-i386-netinst.iso \ + -boot d +``` + +Host system of my `qemu-1.0-rc3` test is Debian GNU/Linux 6.0.2 amd64. +With `qemu-2.1.2` it is Debian 8.1 amd64. +Both had access to the Internet when the guest was installed. + +---------------------------------------------------------------------- + +Preparations on guest system Debian GNU/Linux 6.0.3 i386 + +There appears no `/dev/sr` for the passthrough drive. Thus libburn will not +list it by its drive search function. One may use it nevertheless. But +xorriso will only do so if prefix "mmc:" is used with the address: +``` + -dev mmc:/dev/vda +``` +The drive will be listed by libburn if there is a symbolic link `/dev/sr*` +pointing to it. On Debian 6, this link persists only if it is created +by an udev rule. + +In `/lib/udev/rules.d/50-udev-default.rules`: +``` + KERNEL=="vda", SYMLINK+="sr1" +``` + +libburn on Linux needs rw-permission for the drive's device node. +The virtual device `/dev/vda` is in group "disk". Usual for CD drives is +group "cdrom", to which i (or the Debian installer ?) have added my +normal user when i installed the guest system. +Like with the symbolic link, such a change persists on Debian 6 only as +udev rule. + +In `/lib/udev/rules.d/91-permissions.rules`: +``` + KERNEL=="vda", GROUP="cdrom" +``` + +This should yield +``` + lrwxrwxrwx 1 root root 3 Nov 8 11:19 /dev/sr1 -> vda + brw-rw---- 1 root cdrom 254, 0 Nov 8 11:19 /dev/vda +``` + +xorriso version must be >= 1.1.8 +``` + $ xorriso -version +``` +tells the versions of its components on stdout: +``` + ... + xorriso version : 1.1.8 + ... +``` + +If your distro's xorriso is too old, consider to get and build GNU xorriso. +``` + http://ftpmirror.gnu.org/xorriso/xorriso-1.1.8.tar.gz +``` +Do +``` + $ tar xzf xorriso-1.1.8.tar.gz + $ cd xorriso-1.1.8 + $ ./configure && make +``` +Either do as superuser +``` + # make install +``` +or execute it where it was built as +``` + $ ./xorriso/xorriso ...arguments... +``` +After compilation, this binary does not depend on files in the build +directory. You may move it to any other location. + +For details about the following xorriso commands, read +``` + man xorriso + man ./xorriso/xorriso.1 +``` +or with the same content +``` + info xorriso + info ./xorriso/xorriso.info +``` +Or read the [online man page of xorriso](http://scdbackup.sourceforge.net/man_1_xorriso_devel.html). + + +Note that the sequence of xorriso arguments matters. They are commands +which get performed one after the other. +This differs from the behavior of mkisofs, cdrecord, et.al., +which parse all arguments and then perform actions in a hardcoded +sequence. + +Writing happens automatically if ISO filetree changes are pending +at the end of the program run. This is like with other burn tools. +(There is a command `-commit` for intermediate writing e.g. in dialog +mode.) + +---------------------------------------------------------------------- + +Listing accessible drives: +``` + $ xorriso -devices +``` +shows on stdout: +``` + 0 -dev '/dev/sr0' rwrw-- : 'QEMU ' 'QEMU DVD-ROM' + 1 -dev '/dev/sr1' rwrw-- : 'Optiarc ' 'BD RW BD-5300S' +``` + +---------------------------------------------------------------------- + +The burn tests are presented here for unformatted DVD-RW media. +The xorriso commands apply also to other types of optical media. +See "Other applicable media types:" further below. + +---------------------------------------------------------------------- + +Inspecting drive and medium: +``` + $ xorriso -outdev /dev/sr1 -toc +``` +should show on stdout something like +``` + Drive current: -dev '/dev/sr1' + Drive type : vendor 'Optiarc' product 'BD RW BD-5300S' revision '1.04' + Media current: DVD-RW sequential recording + Media product: RITEKW04 , Ritek Corp + Media status : is written , is closed + Media blocks : 306592 readable , 0 writable , 2298496 overall + TOC layout : Idx , sbsector , Size , Volume Id + ISO session : 1 , 0 , 106696s , ISOIMAGE + ISO session : 2 , 135536 , 108385s , ISOIMAGE + ISO session : 3 , 250240 , 56202s , ISOIMAGE + Media summary: 3 sessions, 271744 data blocks, 531m data, 0 free +``` + +---------------------------------------------------------------------- + +Blanking to single session capability: + +This medium has to be blanked before further writing. For the DAO +test, one can save time by fast blanking, which xorriso normally +dislikes because the result is not capable of multi-session: +``` + $ xorriso -outdev /dev/sr1 -blank deformat_quickest +``` +should report on stderr +``` + ... + xorriso : UPDATE : Blanking ( 1.0% done in 2 seconds ) + ... + xorriso : UPDATE : Blanking ( 95.4% done in 36 seconds ) + xorriso : UPDATE : Blanking ( 99.0% done in 37 seconds ) + ... + Media current: DVD-RW sequential recording + Media status : is blank + Media summary: 0 sessions, 0 data blocks, 0 data, 4489m free +``` +Do not worry if the pacifier messages show no neat percentage progress. +Some drives report "1.0%" until they are done. Some report "1.0%" +after "99%". + +---------------------------------------------------------------------- + +Writing a DAO session: + +Use one or more moderately sized directories as input. Here: `/usr/bin`. +Terminate the list of `-add` arguments by argument `--`. +It is important to have command `-close on` among the arguments. +``` + $ xorriso -md5 on -outdev /dev/sr1 -close on -add /usr/bin -- +``` +should report on stderr +``` + ... + xorriso : UPDATE : 594 files added in 1 seconds + ... + xorriso : UPDATE : Thank you for being patient. Working since 2 seconds. + xorriso : UPDATE : Writing: 32s 0.1% fifo 100% buf 0% 0.1xD + ... + xorriso : UPDATE : Writing: 2704s 5.1% fifo 11% buf 0% 3.9xD + ... + xorriso : UPDATE : Writing: 20208s 38.2% fifo 52% buf 99% 4.0xD + ... + xorriso : UPDATE : Writing: 52885s 100.0% fifo 0% buf 99% 0.0xD + ISO image produced: 52735 sectors + Written to media : 52885 sectors at LBA 0 + Writing to '/dev/sr1' completed successfully. +``` +Do not worry if there is no progress to see for a few dozen seconds +at the beginning. +The run will last at least as long as writing of 1 GB would need. +If you write less data, then there will be a lot of zero progress +messages at the end of writing. + +---------------------------------------------------------------------- + +Checkreading the result: +``` + $ xorriso -md5 on -indev /dev/sr1 -check_md5_r sorry / -- +``` +The word "sorry" sets the severity class of the event message, which is +emitted in case of MD5 mismatch. (See man xorriso, "Exception processing".) + +This should report on stderr +``` + ... + Drive current: -indev '/dev/sr1' + Media current: DVD-RW sequential recording + Media status : is written , is closed + Media summary: 1 session, 52885 data blocks, 103m data, 0 free + Volume id : 'ISOIMAGE' + xorriso : UPDATE : 568079 content bytes read in 5 seconds + xorriso : UPDATE : 17074k content bytes read in 10 seconds + ... + xorriso : UPDATE : 103.7m content bytes read in 35 seconds + File contents and their MD5 checksums match. +``` +and the exit value should be 0, if no mismatch was reported. + +A mismatch message would look like +``` + ... + MD5 MISMATCH: '/usr/bin/ncursesw5-config' + ... + Mismatch detected between file contents and MD5 checksums. + xorriso : SORRY : Event triggered by MD5 comparison mismatch + xorriso : NOTE : Tolerated problem event of severity 'SORRY' + xorriso : NOTE : -return_with SORRY 32 triggered by problem severity SORRY +``` +and the exit value would be non-zero. + +---------------------------------------------------------------------- + +Blanking to multi-session capability: +``` + $ xorriso -outdev /dev/sr1 -blank as_needed +``` +This will need as long as writing the DVD-RW up to its end. +Blanking option `as_needed` lets xorriso decide what to do in order +to make the medium writable from scratch. With DVD-RW it will decide for +`-blank all`. + +The report on stderr should end by +``` + ... + xorriso : UPDATE : Blanking ( 98.9% done in 902 seconds ) + xorriso : UPDATE : Blanking ( 99.0% done in 903 seconds ) + xorriso : UPDATE : Blanking ( 99.0% done in 904 seconds ) + Blanking done + xorriso : NOTE : Re-assessing -outdev '/dev/sr1' + Drive current: -outdev '/dev/sr1' + Media current: DVD-RW sequential recording + Media status : is blank + Media summary: 0 sessions, 0 data blocks, 0 data, 4489m free +``` + +---------------------------------------------------------------------- + +Writing multiple sessions (DVD-RW write type Incremental): + +This time do not perform command `-close on`, so that the medium +stays writable: +``` + $ xorriso -md5 on -dev /dev/sr1 -add /usr/lib -- + ... + xorriso : UPDATE : Writing: 105280s 98.6% fifo 0% buf 77% 3.5xD + xorriso : UPDATE : Writing: 106796s 100.0% fifo 0% buf 62% 2.2xD + xorriso : UPDATE : Closing track/session. Working since 44 seconds + ... + xorriso : UPDATE : Closing track/session. Working since 77 seconds + ISO image produced: 106646 sectors + Written to media : 106800 sectors at LBA 0 + Writing to '/dev/sr1' completed successfully. +``` +Checkread like after the DAO test: +``` + $ xorriso -md5 on -indev /dev/sr1 -check_md5_r sorry / -- + ... + xorriso : UPDATE : 204.0m content bytes read in 63 seconds + File contents and their MD5 checksums match. +``` +Writing the second session looks like the first one. Just use another +set of input files to get a visible change in the ISO 9660 file tree: +``` + $ xorriso -md5 on -dev /dev/sr1 -add /usr/bin -- + ... + Written to media : 53408 sectors at LBA 135488 + Writing to '/dev/sr1' completed successfully. +``` +And checkread the whole tree of files (i.e. both sessions): +``` + $ xorriso -md5 on -indev /dev/sr1 -check_md5_r sorry / -- + ... + xorriso : UPDATE : 307.8m content bytes read in 89 seconds + File contents and their MD5 checksums match. +``` +At the end of writing a final session, the medium can be closed. +It will not take more writing unless it gets blanked or formatted. +So use command `-close on` to demand closing after writing. +``` + $ xorriso -md5 on -dev /dev/sr1 -close on -add /usr/sbin -- + ... + Written to media : 16160 sectors at LBA 195056 + Writing to '/dev/sr1' completed successfully. +``` +Checkread +``` + $ xorriso -md5 on -indev /dev/sr1 -check_md5_r sorry / -- + ... + Media current: DVD-RW sequential recording + Media status : is written , is closed + Media summary: 3 sessions, 176368 data blocks, 344m data, 4064m free + ... + xorriso : UPDATE : 337.7m content bytes read in 97 seconds + File contents and their MD5 checksums match. +``` + +----------------------------------------------------------------------------- + +If the drive tray can move by itself, you may now eject the medium: +``` + $ xorriso -outdev /dev/sr1 -eject all +``` + +----------------------------------------------------------------------------- + +Other applicable media types: + +These test runs for sequential DVD-RW may be performed on CD-RW with the +same xorriso arguments. Be aware that `/usr/lib` will hardly fit on a CD. +So choose smaller directories for CD. + +`-blank deformat_quickest` addresses a peculiarity of DVD-RW. +It will work on other media like `-blank fast`. + +Except the blanking runs, the tests may also be performed on BD-R, DVD-R, +DVD+R, and CD-R. But you would waste two media by this. + +The first session on CD will always be written with write type SAO, +further sessions will be written with TAO. + +CD-R and DVD-R have a simulation mode. It can be enabled by xorriso +command `-dummy on`, but of course it will not produce readable results. +So this simulation is usable only for first sessions on blank media. + +----------------------------------------------------------------------------- + +Now for formatted overwritable media: + +All blank, write and check runs of above tests "Writing multiple sessions" +may also be performed with DVD+RW, DVD-RAM, formatted DVD-RW, and BD-RE. +There is no way to close formatted media. The command `-close on` +gets silently ignored. + +The write methods and states of formatted media differ from those of +sequential media. But xorriso presents to the user a unified +multi-session usage model, under the assumption that all emulated +sessions contain ISO 9660 filesystem images, which successively +build on each other. + +So from the view of xorriso commands, the only task which makes +them differ from sequential media, is to apply optional formatting +or re-formatting. +A special case are BD-R, which xorriso may format but will not bring +into (pseudo-) overwritable state. Formatted BD-R perform Defect +Management by default, which checkreads during writing and replaces +bad block. + +The mandatory formatting of unused DVD+RW and BD-RE is done by xorriso +automatically. Just start a normal write run. DVD-RAM are sold formatted. + +xorriso treats overwritable media with a valid ISO 9660 filesystem as +appendable media. To make then writable from scratch, apply +`-blank as_needed`, which will actually write a few bytes into the PVD +(superblock) of the ISO filesystem to invalidate it. + +De-formatting is only possible with DVD-RW. E.g. by `-blank deformat`. + +----------------------------------------------------------------------------- + +Format DVD-RW for overwriting without intermediate blanking, +or format BD-R for Defect Management: +``` + $ xorriso -outdev /dev/sr1 -format as_needed +``` +should report on stderr +``` + ... + xorriso : UPDATE : Formatting ( 99.0% done in 912 seconds ) + Formatting done + xorriso : NOTE : Re-assessing -outdev '/dev/sr1' + Drive current: -outdev '/dev/sr1' + Media current: DVD-RW restricted overwrite + Media status : is blank + Media summary: 0 sessions, 0 data blocks, 0 data, 4488m free +``` +As with blanking, one should not worry if the progress messages show +unplausible percentages. Some drives are more equal than others. + +Formatting is said to be much stress to the medium. `-format` option +`as_needed` applies it only to yet unformatted media. + +When performing above write tests, take care to use `-blank as_needed` +rather than `-blank deformat_quickest`. Else you will get a sequential +unformatted DVD-RW rather than a formatted DVD-RW which xorriso is +willing to write from scratch. +There is no use in a separate "DAO" test on overwritable media anyway. + +----------------------------------------------------------------------------- + +Change the formatted size of a BD-RE: + +First learn about formatted size and proposals of other sizes. +(One can issue own wishes, too. See in man xorriso, command `-format`.) +``` + $ xorriso -outdev /dev/sr1 -list_formats +``` +should tell on stdout +``` + ... + Format status: formatted, with 23610.0 MiB + BD Spare Area: 0 blocks consumed, 131072 blocks available + Format idx 0 : 00h , 11826176s , 23098.0 MiB + Format idx 1 : 01h , 11564032s , 22586.0 MiB + Format idx 2 : 30h , 11826176s , 23098.0 MiB + Format idx 3 : 30h , 11564032s , 22586.0 MiB + Format idx 4 : 30h , 12088320s , 23610.0 MiB + Format idx 5 : 31h , 12219392s , 23866.0 MiB +``` +So lets go back from 23610.0 MiB to the default size of 23098.0 MiB +``` + $ xorriso -outdev /dev/sr1 -format by_index_2 -blank as_needed + ... + Media summary: 2 sessions, 105470 data blocks, 206m data, 22.4g free +``` +Although the heads of the old sessions might remain readable after +`-format`, better do not rely on this and a append `-blank as_needed` to +avoid any data corruption. +If you want to keep the data, then make at least a checkread run. + +Check whether the size has changed: +``` + $ xorriso -outdev /dev/sr1 -list_formats +``` +should tell on stdout +``` + ... + Format status: formatted, with 23098.0 MiB + BD Spare Area: 0 blocks consumed, 393216 blocks available + ... +```