Re: Software raid 1 w/raidhotadd
hi ya nate
On Wed, 22 Jan 2003, nate wrote:
> Alvin Oga said:
>
> > i'd make sdb1 also "raid autodetect"
> > so you can boot even if sda or sdb dies
>
> sd[ab]1 is my /boot partition, currently I have LILO installed into the
> MBR of sda, lilo can be a real bitch to install on anything but the first
your system should boot if sda is removed
your system should boot if sdb is removed
your system should boot if you boot from fd or cd ( w/ raid support )
x> > Device Boot Start End Blocks Id System
x> > /dev/sdb1 * 1 2 16033+ 83 Linux
x>
x> i'd make sdb1 also "raid autodetect"
x> so you can boot even if sda or sdb dies
i claim your stystem is NOT raid1 for its booting
/dev/sdb1, it should also be set to raid autodetect....
otherwise you wont be able to boot properly with either disk removed
( disk failures ) or under normal booots
if you cannot boot with either disks disconnected... there is no point
in trying to make a raid system if it wont boot ?? .. well okay,
you can still try to protect(mirror) data ( /home ) in raid1
x> /dev/sdb2 3 2213 17759857+ 5 Extended
x> /dev/sdb5 3 63 489951 fd Linux raid autodetect
> disk(usually get the dreaded LI message when trying to boot). Any ideas
> on how to configure LILO(or grub, don't have any experience but it looks
> like a nice bootloader) to install to the 2nd disk? I am unable to boot
> the system with a floppy,
did you make a boot floppy w/ the same kernel you're using in lilo.conf
- try using syslinux to make your boot floppy
http://www.Linux-Consulting.com/Boot/
( see the Boot.syslinux section )
( dd and/or lilo for making a boot floppy is a time killer )
you do NOT install lilo into each disk separately, as if it was separate
disks
you should have in lilo.conf
...
boot=/dev/md0
...
root=/dev/md0
> I tried for about 30 minutes last night and all
> attempts failed when the SCSI driver tried to load. really strange. the
to boot a scsi device...you will invariably need to use initrd to
install your scsi driver modules unless it is compiled into your kernel
> VERY SAME driver/kernel rev(self compiled) boots perfectly from HD. The
> rescue kernel on the debian CD is 2.2.20 which doesn't have raid 0.90
> support nor reiserfs support.
yup.. generic stuff is not always good for tweeking
> I wish I could make a boot floppy that had
> a kernel that didn't puke.
use the /boot/vmlinuz-2.4.19 or whatever it is you used to boot normally
> > to swap out a disk
> >
> > # raidsetfaulty /dev/md0 /dev/sdb2
> > # raidhotremove /dev/md0 /dev/sdb2
> > #
> > # -- after adding a new disk... watch it resync
> > # raidhotadd /dev/md0 /dev/sdb2
> >
> > more sw raid stuff
> > http://www.1U-Raid5.net/HowTo/Commands.uhow2.txt
>
> that worked wonderfully :) thanks! I rebooted the system earlier and
> raidhotadd worked, then when i saw this mail I yanked the drive again
> and tried the above commands and it's almost done rebuilding the last
> array.
good ... and it does take a while to rebuild/resync the disks
> > anybody wanna use 12 laptop drives ( 80GB each ) for their raid boxes ?? (
> > its an interesting idea )
>
> 80gig laptop drives! damn. last time I checked on laptop drives the
> biggest I saw was about 30gig .. I need to swap the drive on my thinkpad
> T20, the drive in there seems louder then my 5-disk raid array in my
> redhat box(7200+RPM SCSI disks), never heard a disk so loud before.
yup... $400 for 80GB laptops...
c ya
alvin
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