HDC Errors When Booting From CDROM...Solved?

[gwalther]

I regularily boot Tinycore on three computers from cdroms.  Using Version 3.6 and 3.8.4,  I recieve a number of error messages at boot time, relating to HDC, and a resulting increase in boot times.  Following the messages Tinycore boots successfully.   I do not get these messages and delays when using version 3.3.  The messages I get are similar to those reported by other users in these forums.

I tried reburning a new  iso at slower speeds as suggested in the forums., I also tried various boot codes,  as suggested like ...ide-core.nodma...all with no success.  The cdrs where all burned, in winxp, using ..CDBurnerXp, version 3.0.116.

Finally I tried burning the iso using ....cdrecord.... in tinycore... as suggested in the forums.   and SUCCESS...no more error messages during boot.

I used the following command to burn the iso:

cdrecord dev=ATA:1001,0,0 speed=10 padsize=63s -pad -dao -v -eject  /home/tc/tinycore-current.iso

This suggests several questions:

1.  Did the other users who got the error messages,also  burn their cdr in windows?  If so what program did they use to burn the iso?

2.  Are there users who do not get the error messages,  who burned their cdr in windows?  If so what program did they use?

3.  Was there a change in the tinycore boot process after version 3.3 that might explain why these error messages  happen?

4.  I tried looking at  the two CDR's, the one that works and the one that does not, and can not see a difference...What am I missing?..What does cdrecord do the CDBurnerXp does not???

[Rich]

Hi gwalther
Thanks for moving this subject to a new thread. I burned my TC2.11 and TC3.4 discs using ImgBurn
under Win98 and WinXP respectively.
I'm glad to hear your error messages are gone too.

[ljk]

Hello gwalther,

I tried some stuff that may (or may not) help shed some light on what's going on with the boot errors.  I made bootable CD's from iso's for TC 3.4.1, 3.5, 3.6, and 3.8.4. I used Win98 with BurnCDCC (free from TeraByte) and Wary Puppy Linux 5.1.1 with Burniso2cd (developed by the Puppy linux community, I believe).  That was a total of 8 CD's, 4 from Wind98 and 4 from Puppy Linux. Each TC had one CD made with Win98 and one CD made with Puppy Linux.  All CD's were finalized.  All CD's made with Win98 gave the errors during boot.  All CD's made with Puppy Linux did NOT give the errors during boot.

I used Nero's scan tools to scan the CD's and check the files.  The scans indicated that the files on all the CD's were OK.  However, the Win98 CD's had an "unreadable" area at the end of the data.  The Puppy Linux CD's did not show this "unreadable" area.  I expected that the "unreadable" area would be there in Win98.  All the CD's that I've made with Win98 and either BurnCDCC or Nero Express seem to have it.

I also checked the MD5 hashes for all the files between the different TC's.  In other words, was "tinycore.gz" in TC 3.8.4 equivalent on both the Win98 and Puppy Linux CD's.  As you would expect, all the files were equivalent between Win98 and Puppy Linux CD's with respect to the various TC versions.  I think that this indicates that the Win98 "unreadable" area is not part of any of the files.  The "unreadable" area may be causing the boot errors, but it seems to me that the errors are not keeping TC from working properly.

I didn't have a TC 3.3 bootable CD to check.  I did have a TC 3.2 CD that does NOT give the boot errors.  It was made with Win98 and BurnCDCC.  It did have the "unreadable" area as shown by the Nero scan tools.

I've made bootable CD's for other distributions (Puppy Linux's, Slitaz, Webconverger, and others) using Win98 and BurnCDCC.  Those CD's don't seem to give the boot errors.

Maybe some TC's are seeing junk left by Windows at end of the burned area and are warning about it.  I'm afraid that I've started ignoring those warnings.  Even though the warnings or errors are there, TC seems to be working fine for me.

Thanks.  Take care.
LJK

[thane]

I've had problems with various TCL ISO CDs burned with Windows 7 (my wife's PC). TCL boots OK but the CD drive keeps running and when I shutdown there's an I/O error message (sorry I forget the exact text). Since I've only tried it in Windows 7 on that one box I haven't been able to narrow down what's causing it. My office PC (Windows XP) burns them OK.

[Rich]

Here's a basic explanation of what's going on.

When the sectors of a CD are written, there is more than just your data being recorded. A sector
looks like this:

  12            4         2,048             4                 8                276
Sync    Sector ID     Data    Error detection    Zero    Error correction

The numbers represent the number of bytes. The  Sync  is used to determine where a sector begins.
The  Sector ID  is the sector number on the disc. Any sectors which are not written to, lack the Sync
marker. Now here's where the error comes in. If the OS (or driver or user program) performs read
ahead buffering, what happens after the last written sector is read? It will attempt to pre-fetch the
next sector so that it's already in RAM in case it's requested, but it will fail with a seek error since
without a  Sync marker  (and Sector ID) it won't be able to find it. That's where those  pad  arguments
come in, they append a bunch of sectors with the  Data  section zeroed so that when reading ahead,
valid sectors will be found.

I'm re-posting this link for anyone getting seek errors when booting from a CD.
http://www.troubleshooters.com/linux/coasterless.htm
Go to this thread if you wish to read more about the symptoms.
http://forum.tinycorelinux.net/index.php/topic,9743.msg53090.html#msg53090

[gwalther]

Thanks for the replies.

Rich - I guess that means TC either started using "read ahead buffering" or changed the way errors are reported during boot, in recent releases, as my old burn program worked without nuisance boot errors on earlier TC releases (and other distros...Slax Slitaz DSL...).

Anyways, I found another free Windows burn program that produces CDR's without the nuisance boot errors.  It is called PowerIso...(version 4..  It has the added advantage in that it allows you to open the iso and edit files.  I use it to add additional boot codes to isolinux.cfg...(waitusb=10) before burning.

[Rich]

Hi gwalther
Actually, in this case, the excerpt from the  cdrecord  manual in the troubleshooters link above lists
the culprit as being the ISO9660 file system driver. What may have happened is that the layout of
the ISO file changed. For example, If the  f2, f3, and f4 help files used to be at the end, that may
have been enough to satisfy any read ahead requests.

[ljk]

@ Rich,

Thanks for the clear explanation.  It really helped me to better understand  "coasterless.htm".

@gwalther,

Thanks for the tip about PowerIso.

Take care.

ljk