DMA issue caused crash and file system inconsistency

[Lowell Gilbert]

Bert Lagaisse <bert.lagaisse at cs.kuleuven.ac.be> writes:

> I did some stupid newbie things:
> 
> I have 2 cdroms, a plextor 8/4/32A and a 50x aopen cdrom.
> 
> I added the line hw.ata.atapi_dma="1" to loader.conf
> The plextor now uses WDMA2
> The aopen cdrom still uses PIO4 (dma worked under wintendo 2000)
> 
> After I tried to enable DMA (using atacontrol) on my aopen cdrom and
> mounted it, the system crashed (freebsd 4.9-RELEASE)
> 
> result :
> 
> During the reboot i got an error and had to run "fsck"
> 
> I did, and answered yes to all the questions. (kinda stupid, I know)
> 
> The system booted but startx couldn't find /var/log/XFree86.0.log
> It seems that /var/log was completely removed
> 
> mkdir log in /var solved the problem
> 
> What else can I expect after a file system inconsistency ?

A bunch of files are missing, too.  Certainly the log files themselves
(many of which will not be created if they don't exist), possibly
others.  

> And how do I solve the cdrom DMA problem ?

Do you need to?