Sounds like this would make a great class. A howto on setting up disks (and maybe other devices that act like disks). And Brian seems like he would make a great instructor. :-)
On Sat, 2006-06-03 at 22:36, Brian McCullough wrote: > On Sat, Jun 03, 2006 at 09:47:10PM -0400, T. Bryan wrote: > > On Saturday 03 June 2006 09:14 pm, Brian McCullough wrote: > > > > > Here, Rick is combining two different technologies, that may confuse > > > you. > > > > Yes and no. I am also trying to use LVM on top of a RAID 1 device. Of > > course, since this is the first time I've created a software RAID under > > Linux, and it's also the first time I've used LVM....yeah, a bit of > > confusion. :) > > > > > The first, which is RAID ( type 1 -- Mirroring ) is what he used > > > sdb5 for. Then he used LVM on top of that RAID device to create, first, > > > a Physical Volume, and then a Volume Group ( VG ). Yes it was > > > unformatted, or if it wasn't he is in trouble! > > > > I think that he's fine. I don't think that I was. My notes say that the > > first time I tried this, I did the following. > > > > Created /dev/hde1 and /dev/hdg1 as Linux partitions > > Formatted both partitions as ext3 > > Created the RAID device /dev/md0 using /dev/hde1 and /dev/hdg1 > > Created a physical volume on /dev/md0 > > Created a volume group on /dev/md0 > > > > Then the rest of the stuff that matched what Rick had done last time: > > creating volume groups, formatting the logical devices, mounting the > > logical devices. > > So....when I try this again, I'll set the partition type to LVM, and > > I'll skip the part where I formatted the partition. Perhaps that's > > how I got myself into trouble. :) > > Tom, > > In a sense, you did things a bit upside down. You have to think of both > RAID and LVM as producing block devices, while your ultimate goal is a > filesystem, formatted in the format you like. ( ext2, ext3, etc. ) > > As you understand, you need to layer things to get the effect that you > want. This is something that I tend to do for any client machine where > things are worth saving -- RAID saves you from some hardware errors -- > it won't save you from typing "rm" but.... The RAID device is like one > or more actual disk drives. Then LVM allows you to assemble one or more > "physical" disk devices into a seamless whole, which you then subdivide > as necessary for your own partitioning scheme. You also understand that > this partitioning scheme is completely flexible, and that you can change > the size of any "partition" as you like, when you like. Up to this > point, you are, in effect, dealing with the devices -- now you actually > allocate, format and mount the various parts of your filesystem. > > > Your procedure should be -- actually, you have two alternatives, > although I will only give you the preferred one. > > Use fdisk to create partitions for your RAID device or devices. Each of > those partitions will be coded as "fa" if I remember correctly -- it is > the "automatic RAID partition type" -- check fdisk. Then use mdadm to > assemble each RAID device from the various partitions that comprise it. > Once you have those RAID devices, use pvcreate to mark them as being > initialized for LVM use. This makes a mark in the first block of the > RAID device ( or partition ) which LVM uses to identify devices that it > is using. Then use vgcreate to assemble the PVs into volume groups. > This also makes marks in the partitions, showing them as belonging to > that VG. A record is also kept in /etc/lvm of all of this work, which > should be backed up periodically. ( read up on vgcfgbackup / > vgcfgrestore ) Finally, use lvcreate / mke2fs to create the actual > components of your filesystem. Note, however, that in your lvm.conf > file, you need to check your filters, to make sure that ONLY the "mdX" > device is scanned, NOT the sdaX, sdbX devices. > > > > ---Tom > > > Brian > > > ______________________________________________________________________ > > -- > 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/
