Difference between revisions of "Downloading FAQ"

From Knoppix Documentation Wiki
Jump to: navigation, search
(Q: My computer won't boot from CD. What should I do?)
(Added Line 6 MD5 Checksum Utility link)
Line 44: Line 44:
* [http://md5summer.org/download.html MD5summer]
* [http://md5summer.org/download.html MD5summer]
* [http://www.slavasoft.com/hashcalc/  SlavaSoft HashCalc]
* [http://www.slavasoft.com/hashcalc/  SlavaSoft HashCalc]
* [http://www.line6.com/software/?hardware=All&name=MD5+Checksum+Utility&os=All&submit=Show%3A Line 6 MD5 Checksum Utility] -  Very simple account creation required for download.

Revision as of 15:39, 19 July 2005

This FAQ is comprised of both downloading & burning questions.

Return to Knoppix FAQ

Tip: Use CD-RWs instead of CD-Rs every time you can - save your budget and our environment!


Q: How do I get the CD/current beta?

A: Several possibilities:

  • Download
    • Download with Bittorrent from The Unix-AG BitTorrent Tracker. Get BitTorrent (if you need it) from http://www.bittorrent.com/. Be sure you set up your firewall setting properly. Properly configured BitTorrent will usually download Knoppix much faster than getting it from the mirrors.
    • Download from one of the mirrors listed at The Knoppix Download Page . Try to choose the mirror nearest you for best results.
    • If you download the ISO image file from a mirror, then also download the accompanying MD5 file too. If you download by BitTorrent then you will also get an md5 file automatically, although BitTorrent has it's own checks and the md5 is only a second recheck of a good download.
  • Order a CD
    • If a 700Mb download is too much for your bandwidth capabilities, you can order the newest CD from a retailer on The Knoppix Order Page

Q: Can you download Knoppix in parts if you have a low bandwith (28.8 Kbps) such a pausing the download and continue it another day?

A: Yes, Bittorrent supports resume, and so do many ftp clients such as wget ( use wget -c ) or ncftp. You can use other download managers too.

Q: What are these strange MD5 files that accompany the ISO CD images?

A: The files with the .md5 extension contain checksums for the actual CD ISO images. A MD5 checksum is a way of fingerprinting files. Just like a real fingerprint identifies a single person, a MD5 checksum is unique and matches exactly one file. It is used to verify that the file downloaded matches the original all the way down to the smallest details. In the case of downloading a Knoppix ISO image, the MD5 checksum is used in order to verify that the file downloaded is perfect and not corrupt.

Many file corruption problems have been observed when downloading from the mirrors. It is very important to check the md5 checksum if you use a mirror rather than BitTorrent.

This discussion is about a separate md5 file that you can download from the mirror that you got the Knoppix ISO from, or that comes down as an individual file in the package of files that you get in the package when you download with BitTorrent. DO NOT extract any md5 file from inside the ISO. The ISO does contain an MD5 file that is used by the testCD command, but this is not the file that is discussed here and should not be used to test the ISO download.

When you download both the ISO image for the CD, you also must download it's corresponding .md5 file. The .md5 file is a plain-text file and can be viewed in a text editor or web browser. You can verify that your download was perfect and that the ISO's contents are unchanged by typing "md5sum -c filename.md5" under Linux/Unix.

Further information about MD5 and programs for various OS's can be found at LinuxISO.org and The MD5 Protocol Documentation. Here is a small list of MD5 checksum calculators for Windows™ but note that the methods to verify the checksum & make sure you have a perfect ISO file vary between programs.

Q: What are these strange ASC files that accompany the ISO CD images?

A: Most users can ignore the .asc files. If there is ever an uncertainty as whether or not the ISO image file and it's accompanying MD5 file are originals & untampered, then the .asc files are important. The .asc files are digital signature messages. Digital signatures are a method of authenticating digital information similar to ordinary physical signatures on paper, but implemented using techniques from the field of cryptography. With this you can be sure the ISO image and accompanying MD5 file are genuine, because the .asc file containing the MD5 is signed with Klaus Knopper's PGP key. To verify the file, you need to import PGP key ID 0xBA8F038D from your favorite keyserver, then in Linux you can type "gpg --verify KNOPPIX_Vxxxxxxxxxxxxxxxxx.iso.md5.asc". Then you must check that the MD5 checksum in the .asc file is the same that the MD5 checksum in the .md5 file.

To download the keys, type:

gpg --keyserver pgp.mit.edu --recv-keys BA8F038D

If you want to verify the signed md5 file and the ISO file in one step, you can type:

gpg --decrypt  KNOPPIX_Vxxxxxxxxxxxx.iso.md5.asc | md5sum -c -

Q: I have downloaded the ISO file. How do I burn the ISO? How is the ISO supposed to be burned?

A: First check to see if the ISO that was downloaded is perfect & not corrupt. See the above FAQ labeled #Q:_What_are_these_strange_MD5_files_that_accompany_the_ISO_CD_images.3F. If it passes the MD5 checksum then you must burn the ISO as an image.

  • Linux
    • You can use the command cdrecord or the CD burning program K3b.
  • Windows
    • Quick answer: You will need one 700MB/80min blank CDR. Use a program such as Nero Burning Rom or Roxio CD Creator. You can get a free trial of Nero from their site. In most cases you will want to skip the burning wizard and choose File -> Burn Image or File -> Open. Select the KNOPPIX_Vxxxxxxxxxxxxxxxxx.iso file, then -> Burn.
    • Long answer: Of course the answer depends on the individual program you are using to burn CDs, but all common CD-Writing programs should support the option of burning the ISO as an image, you probably just have to find the right menu option. In the burning program, do not drag & drop the ISO into the burning screen. In the windows explorer, do not attempt to decompress the ISO with something like WinRAR or WinZip. You must CHOOSE to burn it as an image. Do not burn it at a fast speed greater than 16X. You must burn it at a very slow speed preferably 4X or 8X. Burn your CDR as a "Single Session CD" or select finalize. The Mode "Disk at once" or "Track at once" should not matter (have a look at the Online-Help of your burning software).

A common mistake made when burning ISOs: "I downloaded & burned the ISO to CDR as a bootable data disc. Now it boots to a A:\ Caldera DR-DOS prompt." You are probably seeing something like:

Caldera DR-DOS 7.03
Copyright (c) 1976, 1998 Caldera, Inc. All rights reserved.
[DR-DOS] A:\]

This means that the ISO was burned as a bootable CD or bootable data disc. A Knoppix ISO already includes the boot instructions so it is not necessary to burn it as as a bootable data CD. Burning the ISO file as an image will automatically take care of the bootable details.

  • Guides and Tutorials
  • Quick walkthrough example burn Nero Ultra Edition (not Express.)
    • I run it and it automatically starts a "New Compilation" wizard. I immediately click Cancel. Then I go to the File menu and choose Open (or I could just use the keyboard shortcut of CTRL-O). In the Open file dialog box, I change the Files of type from "All Nero compilations and Images" to "Image Files (*.nrg;*.iso;*.cue)". Then I go find the Knoppix ISO file and double-click it to select it. It then brings up the "Burn Compilation" dialog box. I choose a write speed of 4x or 8x. I check-mark the "Finalize CD (No further writing possbile!)". I personally choose the write method of "Disk-at-once" but I know that "Track-at-once" also works. When I am ready, I click on the "Burn" button and Nero will burn the Knoppix ISO to the CDR.

Q: How do I burn an ISO to a CD using NERO?

A: There are different answers for different versions of Nero.

For Nero 5, start the program. You can just hit CANCEL at the wizard menu to get to the main window. Ues the FILE option in the menu near the top of the screen and select the Burn Image ... option in the sub-menu. Find the ISO that you downloaded in the file open box that pops up. Burn at a slow speed. Do not drag and drop the ISO into the file area. Do not take any option to make the CD bootable.

For Nero 6, full version: The Burn Image ... option in version 6 is gone. Use one of the following: Get to the main menu and then use the Open .... choice under the FILE menu, or under RECORDER in the top menu you will find that Burn Image ... has been moved to this menu. In either case use the box that opens to find the ISO file that you downloaded. Burn at a slow speed. Do not drag and drop the ISO into the file area. Do not take any option to make the CD bootable.

For Nero Smart Start: If you are stuck with this version of Nero, start the application. Point to the 5th icon across the top (the one that shows 2 CDs over a box like thing). Choose Burn Image to Disc from the menu that changes below the icons. Find the ISO that you downloaded. Burn slowly.

For Nero Express 6: Under the question "What would you like to burn?", pick the last option, Disc Image or Saved Projects. Use the box that opens to find the ISO file that you downloaded. Burn at a slow speed.

I you do not have a copy of Nero you can download a limited time trial version from Ahead Software. This should give you plenty of time to burn your first Knoppix CD. After the trial expires, if you do not choose to buy Nero you can use Knoppix itself to burn future ISO files.

Q: How do I burn an image on to a CD using B's Recorder Gold from BHA?

A: Close the Wizard dialog if it pops up when you start the application. Drag the KNOPPIX-*.iso file to the lower RIGHT region of the app window. It is shaded in yellow and has the title "Track Type"(The icon with a musical note and a folder will be seen in the middle panel). Right click the left region where it says ")1 DATA -mode1 and from the popup menu choose properties. Choose "ISO compatible" and "create from standard bootable disk image" in the two selection boxes. Then press the record button (Upper left), pick your options, and Voila - one KNOPPIX bootable CD is yours.

Q: How do I burn an ISO to a CD using NTI CD-Maker from Brouderbund?

A: Start NTI. Tell it you want to make a data CD. From the FILE menu near the top of the window, select the sub-menu option "Create Disc from ISO Disc Image File ..." and find the ISO file in the resulting search box that opens. Burn at a slow speed. Do NOT Drag and Drop the ISO into the file area.

Q: How do I burn an ISO with the Microsoft burning software that comes with XP?

A: Burning an ISO is not supported in the Microsoft software. Many OEM that package XP with a computer also include other burning software that will burn an ISO. There are third party free and trial version programs that will burn an ISO file under XP that you can download. A free trial version of Nero is available form Ahead Software.

Q: I have a fast access to a Knoppix-mirror. How can I burn with GNU/Linux this ISO file directly to CD-RW?

- mkfifo KNOPPIX.fifo # mkfifo create a fifo file
- screen ftp mirror ....# screen creates multiple shells in one terminal (handy!) ftp connect to your mirror...
get KNOPPIX-3.10-EN.iso KNOPPIX.fifo #command to copy inside your ftp-session
- C-a C-c # screen will make a new shell
- cdrecord dev=(your burner) speed=4 KNOPPIX.fifo # ftp starts to get data when cdrecord starts to read from fifo
wait; exit; rm KNOPPIX.fifo; exit

(Attention, use "cdrecord -scanbus" before cdrecord to find the correct device of your cd-writer. If you own SCSI hds, you could lose all data of one hd when you use cdrecord with a wrong dev=(controller,id,partiton) !)


This works well and is much simpler: wget -O - URL_OF_IMAGE | cdrecord -v speed=4 -eject -

Q: What option do I use to make the CD (or DVD) bootable?

A: None! Do not use any option in your burning software to make the CD bootable. Just burn the ISO as an image, this will put all of the proper files on the CD in the proper locations and the resulting CD will be a perfect copy of the original Knoppix CD and will be bootable. If you take any option that makes a bootable CD, you will end up with a CD that does not boot into Linux/Knoppix.

Q: My computer won't boot from CD. What should I do?

A: Look in your computer's BIOS (on many computers you need to push the "delete" or F1 key during the POST) to see whether it is set to boot from CD. If this is already set, your computer may not be able to read the CD (some notebooks have problems with black-coated CD's, for example). Some computers will only use the new BIOS settings after a hard reset. Other resources are this page which explains the PC BIOS and this page explains the boot order.

A: Get the Smart Boot Manager, and install to floppy, this should let you boot from any bootable CD. Download Smart Boot Manager. If you want to install from windows, download the sbminst.exe and run it from the Command Prompt like : sbminst.exe -d 0 to install to floppy drive. SBM can also be install to your hard drive's Master Boot Record, so you will not need a floppy at all to boot the CD.

Another really nice boot manager that will let you boot a CD on a system where the BIOS does not support it is XOSL. XOSL is slightly more work to set up, but it is much more powerful and has a much nicer looking user interface. It uses SBM code internally to boot the CD. XOSL must be installed to hard disk, it will not fit on a floppy. For Linux users it is often best to give XOSL it's own small partition (just a few megs in size).

Q: My PC will boot off of the burned disc. It is strange since it loads but then stalls or it loads but is giving me I/O errors. What's going on?

A: You possibly only got a partial download or the download was complete, but corrupt. If this is the case, then the ISO image is defective and the CDR burn of Knoppix is also defective. This is because the data in the missing/changed parts cannot be accessed (sometimes one can even "hear" this because of the sound the CD-ROM drive makes due to repeated read attempts). It appears to work because the directory tree is written at the beginning of the CD and can be correctly read. However, reading the actual contents of the missing/changed parts is impossible, or in other words, accessing the contents fails. If the ISO image was checked & found to be unchanged and not corrupt, then it is possible that the CDR has been improperly burned or a bad piece of CDR media was used. To rule out the possibility of a bad download or a bad burn, some solutions can be found in the section #Q:_What_are_these_strange_MD5_files_that_accompany_the_ISO_CD_images.3F and #Q:_I_have_downloaded_the_ISO_file._How_do_I_burn_the_ISO.3F_How_is_the_ISO_supposed_to_be_burned.3F.

Problems are often seen booting with discs that have been burnt at a high speed. If you checked the md5 file and know that you have a good download of the ISO, and you have followed the other instructions for burning the CD as an image, then be sure that you burn the CD at a slow speed, either 4x or as slow as your burner will let you go (some new burners and newer burning software seem to refuse to burn slower than 8x). High speed burns may work on some systems but not on others. There are also reported cases of the CD working but the boot taking much longer that it should for the system to finish booting. These problems are resolved by a slow speed burn.

If the ISO is good and the burn was done properly and at a slow speed, you may need to use one or more "cheat codes" to boot the disc (see the Cheat Code FAQ for details). In rare cases you may have an optical drive hardware problem (sometimes using CDRW media rather than CDR will help work around this). And be sure that you system is up to Knoppix's minimum requirements. A slow and memory starved system will stall when booting and come up very slowly.

Q: Must I burn Knoppix on CDRW or CDR to be able to test it?

A: When you run another GNU/Linux system, you can copy the content of the Iso-file to your hd and boot it directly from hd. See Hd Based HowTo.

Q: Why does my writer/software not accept to write to my 80 minute CD-R?

A:Some older writers or older versions of writer software cannot recognise the new playing lengths, because the groove is laid more narrowly. Check with your hardware and software manufacturer to see if these newer media are supported. In most cases, updating the writer software's current firmware (check out the web site of the software manufacturer) will solve these problems.

Q: What to do if I haven't got enough space in the CD to burn Knoppix on it?

A: There was previously a response here that said "You can overburn it (http://www.wikipedia.org/wiki/CD )". That is the wrong answer! If the file is correctly downloaded, it will fit on a 700 meg CD (check the md5 sum!!!) It will NOT fit on a 650 meg CD, even with overburn.

There seem to be a lot of people who are confused about the size of the ISO. They either look at the size in bytes and think it will not fit (forgetting that 1 meg is 1024x1024 bytes), or they have done something else wrong like "unpacking" the ISO and then trying to burn it. Most people who report that the ISO will not fit on the CD will never explain back what they did wrong once they resolve the probelm. But the bottom line is that if you properly confirmed the md5 checksum, and saw one good ISO file (not multiple files), then the file will fit on a 700 meg CD if burnt properly.

Q:Why do 750 MB fit onto an audio CD but only 650 MB onto a data CD?

A: A sector of a CD consists of 2352 bytes. With an audio CD, these are used completely for audio information. With data CDs, an additional fault correction is inserted, and the usable capacity shrinks to 2048 bytes. A 74 minute CD consists of 74x60x75 = 333000 sectors. With 2048 bytes per sector, this gives a usable capacity of around 650.1 MB, with 2352 bytes per sector it gives around 746.6 MB. This therefore also produces a difference in data rates for reading/writing: 172 kbps with audio and 150 kbps for data.

Knoppix needs a 700 meg CD or CDRW to burn the CD. It wil not fit on a 650 meg CD.

Q: After I've used KNOPPIX, my "other" OS suddenly shows a blue screen with the message "File kernel.exe not found or defective" and "reinstall..." shortly after boot.

A: Simply take the KNOPPIX CD out of the CD-Rom drive and restart the computer.