OT 2nd posting pci ata card ??

[Antony Gelberg]

Dave S wrote:
> On Sunday 02 April 2006 00:55, Patrick Siglin wrote:
> 
>>Dave S wrote:
>>
>>>On Saturday 01 April 2006 21:15, Dave S wrote:
>>>
>>>>On Saturday 01 April 2006 20:55, Antony Gelberg wrote:
>>>>
>>>>>Dave S wrote:
>>>>>
>>>>>>On Saturday 01 April 2006 20:28, Antony Gelberg wrote:
>>>>>>
>>>>>>>Dave S wrote:
>>>>>>>
>>>>>>>>Hi all,
>>>>>>>>
>>>>>>>>This is a second posting because I could really do with some advice.
>>>>>>>>I have a raid HDD on hda and hdc, works a treat.
>>>>>>>>
>>>>>>>>I have a DVDRW on hdb, it works but cripples my system when I use
>>>>>>>>it. I need a workaround.
>>>>>>>
>>>>>>>Is DMA on for that drive?  If not, turn it on.  man hdparm.  It may
>>>>>>>well make a difference.  There's so much conflicting information
>>>>>>>about this, and most people who comment have no idea about how IDE or
>>>>>>>DMA work (me included).
>>>>>>
>>>>>>Yep DMA is on, and the drives fly. i am happy with the RAID
>>>>>>performance it is faster than a single drive (though not massively so)
>>>>>> but when i use hdb it all but locks up my machine.
>>>>>
>>>>>I meant for hdb.
>>>>
>>>>Opps sorry ... I enabled DMA on hdb and got some hda seek errors in
>>>>syslog, some failing to boot due to unable to module problems and fsck
>>>>failure (gulp!) so I turned off DMA for hdb and the system became stable
>>>>again
>>>>
>>>>Dave
>>>
>>>Yep I know its odd and should not happen, but there is obviously a
>>>conflict here. Another reason the separate hda & hdb
>>>
>>>Dave
>>
>>It still sounds like both the dvd and one of the hd's are on the same
>>ide interface.
> 
> 
> Yep sure are hda HDD and hdb DVDRW are on one ide interface, hdc HDD is on the 
> second.
> 
> Having read peoples input I am going to buy a ata/133 pci card and move my 
> hda, hdc to the cards ide busses leaving my hdb DVDRW alone on the 
> motherboard bus.
> 
> I have spent a lot of time setting up my system just as I want it, samba, 
> apps, furry dice :) Has anyone any idea how easy / hard it would be to move a 
> software raid from hda,hdc to hde,hdg (I assume that's where they will pop 
> up?)

Don't assume.  Some PCI IDE cards manage to grab hda etc or perhaps it's 
a BIOS issue.  Disclaimer: this advice may hose your system.  It's what 
I would do.  I have backup and you should too.

Plug the devices in and try to boot.  It's possible that magic may 
happen.  If not:
o Boot from a live CD.
o Note what hd* the drives are (dmesg | grep ^[hm]d) and what md* the 
array is (cat /proc/mdstat).
o If the array wasn't detected, assemble it (e.g. mdadm --assemble 
/dev/md1 /dev/hde1 /dev/hdg1).
o Mount and chroot to the array (e.g. mount /dev/md1 /mnt && chroot /mnt).
o Fix the bootloader and fstab if necessary.  I'm hazy on bootloaders 
but it's something like the drive will now be hde, grub loads, and tries 
to boot from hda which of course have nothing connected.  You will need 
to edit /boot/grub/menu.lst.  I'm not sure if you need to re-run 
grub-install as drive allocations have changed in the BIOS etc.
o Exit the chroot (Ctrl-D).  Unmount the array (umount /mnt).
o Reboot without the CD.
o Note the errors, fix them, and try again.  ;)