# 2.6.9 breaking CD burning?!

## fourhead

I just wanted to know if I'm the only one experiencing this: When I switched from 2.6.8 to 2.6.9 (tried both ck-sources & gentoo-dev-sources) on my two PCs CD burning wouldn't work anymore. If I try to delete a CD-RW, K3B gives me an error, when I try to burn, it always complains about insufficient RAM. When I switch back to 2.6.8 on both achines, CD burning works like it should. Whats wrong here?

Tom

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## WeebleToo

I had the same error with the 2.6.9-r1 gentoo-dev-source kernel about memory allocating with scsi interface or something but fixed it with the following.

If you're trying to run k3b as a non-root user try disabling the set uid permission for cdrecord.

There's also another thread that may be similar to what your problem.

https://forums.gentoo.org/viewtopic.php?t=241461

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## mlsfit138

just use cdrao instead of cdrecord.

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## forbjok

Burning works fine here on all the systems I've tried...

CDs on my laptop w/ cdrdao & cdrecord & k3b (probably uses cdrecord)

CD/DVDs on my desktop P4 w/ k3b (dvd+rw-tools and cdrecord?)

I run vanilla 2.6.9 though, and all burning was done either as root directly from console, or from X as root using 'sux'. If you didn't already, try running k3b through 'sux' or logging in directly as root when running cdrecord/cdrdao.

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## ryceck

The main problem with 2.6.9++ is that it is unable to handle the SUID bit on the binary files of cdrdao and cdrecord.

Do this as root:

```

chmod -s /usr/bin/cdrdao

chmod -s /usr/bin/cdrecord

```

And u are able to burn as a regular user again. Just make sure u dont have the K3B-setup program reset the permissions on those files again, cuz that will make the SUID-bit come back.

The only downside here is that it will not burn @ high priority but at regular priority. But this hasnt yet caused any burning problems for me.

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## laue

tnx ryceck,

this fixid a great deal of problems and frustrations for me...

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## eMPee584

nicely solves the problem.

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## Lion

Removing the suid bit enables you to burn again, but prevents cdrecord from increasing its priority. So, when you do this, it is best to burn on an otherwise idle machine. Burn-proof protection in the drive will save your CD, but if the burn-proof of the drive is used, then the quality of the disc is (slightly) reduced.

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## eMPee584

although I could burn cds again, I wasted 4 of them this morning, because my system was under heavy load. why didn't BURNPROOF do anything??????? What's that?

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## Lion

Normally, CDs need to be written in one continuous stream.

When data to the CD writer is interrupted during writing, the laser has to stop.

Burn-proof enables the laser to 'pick up' where it left, but this creates a spot on the CD that, although readers should be able to cope with it, does not have the normal pattern. Therefore, it is best to prevent the use of burn-proof.

Cdrecord does this by increasing its priority to the maximum possible, but it can only do that if it is run as root. With kernels before 2.6.8, this could be done by setting the suid bit, but the kernel developers saw a security hole there. They are working on fixing it, but until then, it is best to burn as real root (not suid, not sudo) or make sure in another way (unloaded machine) that the data stream is not interrupted.

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## Illissius

Thanks for the tip. Odd thing is, when I was previously burning as root, the buffer level tended to fluctuate quite a bit, but now that I'm running it as a user, it stays pegged at 100%, same as under Windows. Kind of counterintuitive, considering that it's supposed to be running at a reduced priority now...

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## liber!

I must say, cd burning under 2.6.9-ck3 works better, than under my previous kernel (gentoo-dev 2.6.5) I had constant a very high buffer, (it did go once under 60%, but the rest of the time around 98%) and the speed was much higher too...

So I'm happy  :Twisted Evil: 

Greets,

Nathan

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## tam

 *ryceck wrote:*   

> 
> 
> Do this as root:
> 
> ```
> ...

 

Thanks!

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## eNTi

i'm still not able to burn in SAO mode as user.

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