[CentOS] Isolinux disk error 20; AX=4280, drive EF

Ed Westphal enwestph at rochester.rr.com
Sun Aug 3 12:41:32 UTC 2008

Thanks Dag. I'm wondering if I'll have a similar problem with a multi CD 
ROM set instead of the one DVD? The system loaded RHEL WS 3, update 4 
Taroon just fine from CD's. I'm leaning towards the same issue you 
mention. The large DVD ISO image is not recognizable by the system. At 
the time the system was put together, there were no DVD ISO images, just 
CD. The DVD ROM drive works just fine. Plays movies etc. The dual boot, 
Win 2000 Pro / Red Hat system would not mount the DVD however. Win XP, 
separate newer machine with a Samsung DVD reader mounts disk just fine 
and reads contents before freezing. It has a Plextor 712SA DVD RW unit. 
The older system has an HP DVD writer 300i. I don't recall who made the 
other DVD ROM.
What do you think, could a CD ROM set solve the boot problem?

Dag Wieers wrote:
> On Sat, 2 Aug 2008, Ed Westphal wrote:
>> Lanny Marcus wrote:
>>>  On Sat, Aug 2, 2008 at 1:37 PM, Ed Westphal <enwestph at rochester.rr.com
>>>  <mailto:enwestph at rochester.rr.com>> wrote:
>>> >  I thought I'd be clever and buy a DVD for 5.2 from LinuxOnline.biz.
>>> >  Well, just got around to trying it with the above results. Does the
>>> >  error mean I have a 'bad' DVD disk image? Please advise. Thanks.
>>>  Boot from the DVD and at the boot prompt, type "linux mediacheck" 
>>> (without
>>>  the quote marks).
>>>  That will check the DVD, to see if it checks out OK. That said, a 
>>> few days
>>>  ago, I installed from a
>>>  DVD that did not pass "linux mediacheck" and that box is running 
>>> OK. YMMV. 
>> Thanks Larry. Not even getting to a boot prompt. First time, it was 
>> saying: 'Press any key to try again'. - gives same results.
>> I've been Googling the above. It seems that there are some 
>> incompatibilities that others have reported with Isolinux? I'm 
>> wondering if others here have seen the problem here? I know about the 
>> checksum error thing. I've done other installs from CD's without a 
>> problem. Thought a DVD would be a better install medium. Perhaps with 
>> my Intel D875PBZ motherboard, there is a conflict loading ISO images? 
>> Don't know. Haven't found any workarounds if that is indeed the case. 
>> I have the latest Intel bios. Is there one install medium provider 
>> that most prefer? To be sure to get good disks. I'd prefer getting a 
>> disk(s) from someone rather than trying to burn my own. Thoughts, 
>> advice appreciated. Thanks.
> I suspect it is not a medium problem but rather an incompatibility (or 
> bug) with isolinux and your DVD drive. So most likely the same would 
> happen with any other provided media (or own-written media).
> I would suggest comparing the MD5 or SHA1 from the DVD with the online 
> provided checksum to make sure the image is intact. But the chances 
> are really slim that the isolinux bootloader got corrupted, so I doubt 
> it will make a difference...

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