Tim Yardley wrote:
I am working with the same type of situation as mentioned here. The following is what I am trying to have done.
- 2 drives are in the system and both connected to the promise controller. - hardware mirroring is desired to be used.
For hardware mirroring you'd need a hardware raid controller. Like a 3ware controller.
- distribution is 7.2 updated with all errata and a custom boot kernel built with the latest kernel to fit it on to a single floppy with network drivers.
Initially, I tried creating the mirror first in the promise bios and then doing the redhat install (via kickstart in my case). This did not succeed. The install would go fine, hde and hdg would show up, but it seemed to be using the drives independantly. Samuel Flory suggested creating 2 arrays of a single drive each.
Thats only to use the drives as normal disks. Keep in mind my instruction were about using the linux md driver.
So, I deleted the mirror array and created 2 stripe arrays, one drive per array. Ran the kickstart again and the system installed and would boot. However, the mounted partitions are on both disks (hde and hdg) according to mount output.
In the kickstart, the partitions were created as follows:
clearpart --all part /boot --fstype ext3 --size=32 part / --fstype ext3 --size=512 part /usr --fstype ext3 --size=1024 part /var --fstype ext3 --size=1024 --grow part /httpd --fstype ext3 --size=512 part /home --fstype ext3 --size=256 part /tmp --fstype ext3 --size=512 part swap --size=1024
Try adding --ondisk=hde to all of the partitions entries.
Seemingly, this would put all the partitions on hde, shouldn't it? I am
confused as to why mount shows them on e and g... as well as about a few
things.
Red Hat attempts use both drives by default.
One, how do I get my mirrored raid set up? Do I just delete the 2
defined stripe arrays and create the mirrored array (after the install)
using the hde drive as the source?
In theroy you could do a normal install on a single drive. Create a one array for each drive in the promise bios. Boot and change your fstab to use ataraid devices instead of hde. (In theroy editing your grub.conf at this step. Might allow you to off boot the hard drive after creating a mirror.) Create a mirror using that drive via the promise bios. Boot from a floppy using the ataraid device as/ and reinstall/fix your bootloader.
Is there anything else that has to be
done?
Also, a few other questions. How do you know if the kernel is using ataraid
or not (I built it into the kernel).
Look in /proc/partitions if there are ataraid devices it's working.
Only the promise binary driver uses sd? devices. The howto's assume you are using the promise binay driver for the install.The major and minor numbers for /dev/hd{eg} are different than /dev/ataraid/d?, is there some sort of conversion that needs to be done in this case? I checked the ata-raid howto but that didn't seem to make much sense. My drives are always recognized as hd{eg}, never as sd? drives.
PS- Using the md driver is far better than either ataraid, or the binary ft driver.
1)Both ataraid, and ft crash if you lose a drive.
2)You can't rebuild the array from linux, and must do the entire sync in the promise bios
3)The Red Hat installer doesn't support the ataraid, or the ft drivers. Red Hat doesn't seem to plan ever support ataraid. (See Arjan's email on the subject in the archives.) Neither does any linux distro I know of. Thus you are screwed for any future updates.
-- There is no such thing as obsolete hardware. Merely hardware that other people don't want. (The Second Rule of Hardware Acquisition) Sam Flory <sflory@xxxxxxxxxxxx>
