Ok thank you . I will give it a shot
-----Original Message----- From: Matt Pusateri [mailto:[EMAIL PROTECTED] Sent: Tue Nov 22 11:18:33 2005 To: Triangle Linux Users Group discussion list Subject: Re: [TriLUG] Adding second HDD then mirroring it John, What you want to do is possible. From my experience and someone correct me if I am wrong. You can't change the orginal harddrive to a raid system after the data is on it. It has to do with how the raid tools record the raid information in the superblocks and also the partition type has to change. I have tried to do this as an excersise and failed due to invalid super-blocks. What you have to do is this. Add the new drive, boot with something like knoppix. 1. congfigure new drive to have a raid partition type (FD I think). you can use the following to dump the partition table of the orginal disk sfdisk -d /dev/<original_disk_device> > partition.out Then use that file to put the partition table on the new disk sfdisk /dev/<new_disk_device> < partition.out Next use fdisk to go change the partition type on the new disk to linux raid on the partitions you want to raid. 2. Then create each raid device on the new disk with a missing raid member mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/<new_disk_device> missing The "missing" after the new disk device is to create a md device with one drive and one missing drive. You may at this point have to do a mdadm -assemble, see the mdadm man page. I can't remember off the top of my head. 3. you should now have MD devices, cat /proc/mdstat use e2fs or what ever tools you need to put the file system structure on the MD device. 4. mount the old disk in some mount point, the new disk in some mount points and rysnc over the data from the new to the old. I would rsync over each individual mount point. 5. chroot into the new mount points, Edit the fstab and inittab files in /etc to refer to the new MD device. Edit grub.conf as well. also sometimes you need to make a new intird, it depends if your kernel recognizes the md devices upon reboot. If you do need to make a new initrd, make sure you mount /proc in your chroot before you do,so that the md devices are picked up. 6. reboot and hope everything comes up. If it does and things are stable on you md devices, then you can use the mdadm command to add your original disk into the raid. Personally if I were to do this I would start with two new disks and just create the raid with both of them and then not have to worry about using your old disk in the new array. It will make your life easier. Sorry this is a quick down and dirty of how to do it. I suggest looking at the various raid Howto's. Here's one that's a little old as it refers to raidtab, which is not used anymore as the raid info is stored on disk in a superblock. http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html Matt P. On Tue, November 22, 2005 9:59 am, John-David Henderson wrote: > Yes, this is what I want to do. Thank you > > -----Original Message----- > From: Brian Henning [mailto:[EMAIL PROTECTED] > Sent: Tue Nov 22 09:52:15 2005 > To: Triangle Linux Users Group discussion list > Subject: Re: [TriLUG] Adding second HDD then mirroring it > > Just to clarify: > > What you want to do is turn your normal, single-drive system into a RAID-1 array by adding a drive and mirroring to it? > > I'm pretty sure all RAID tools are capable of that. I'd start by looking at software RAID, since your system is already up and running. > Try googling for "software raid linux". I'm sure other people will pipe > up to give more info as well. > > Cheers! > ~Brian > > > John-David Henderson wrote: >> I have an issue that needs to be addressed. Can someone direct me where I can find out how to add a second HDD to an existing RedHat 9.0 install then somehow mirror the drive? >> Thanks. >> JD Henderson M:919.649.5589 [EMAIL PROTECTED] > > -- > ---------------- > Brian A. Henning > strutmasters.com > 336.597.2397x238 > ---------------- > -- > TriLUG mailing list : > http://www.trilug.org/mailman/listinfo/trilug > TriLUG Organizational FAQ : http://trilug.org/faq/ > TriLUG Member Services FAQ : http://members.trilug.org/services_faq/ > > > -- > TriLUG mailing list : > http://www.trilug.org/mailman/listinfo/trilug > TriLUG Organizational FAQ : http://trilug.org/faq/ > TriLUG Member Services FAQ : http://members.trilug.org/services_faq/ > > -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/ -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/
