Updated March 10, 2004
Created April 15, 2003

1. Install, setup, and configure the hard drive(s):
   
   I had 5 raid storage boxes, so I set up each raid box as individual raid 5 sets through the hardware manager (BIOS) for those boxes. So now they appear as 5 50GB hard drives.


2. Optionally run lvmdiskscan to see all your drives
3. Create a partition of type "Linux LVM" on each drive:
   
   I ran fdisk on each of these "drives" and made 1 primary partition each. I changed the type of the partition to "8e" which is "Linux LVM".


4. Run pvcreate on each partition:
   
   pvcreate /dev/cciss/c1d0p1
   pvcreate /dev/cciss/c1d1p1
   pvcreate /dev/cciss/c2d0p1
   pvcreate /dev/cciss/c2d1p1
   pvcreate /dev/cciss/c3d0p1
   


5. Create a volume group of these drives using vgcreate:
   
   vgcreate fileshare /dev/cciss/c1d0p1 /dev/cciss/c1d1p1 /dev/cciss/c2d0p1 /dev/cciss/c2d1p1 /dev/cciss/c3d0p1
   
   I got a message back saying something to the effect of:
   default physical extent size = 4MB
   maximum lvm is 255.99GB
   doing automatic backup of volume group "fileshare"
   successfully created and activated
   
   Note: if you need to activate the volume group, you use vgchange -a y fileshare to do that. But we just activated it so that's not necessary to do right now.
   


6. Create a logical volume using lvcreate:
   
   lvcreate --size 255.99G -n share fileshare
   
   I found that this was too big because lvcreate tried rounding up to the next number; however, it did tell me that I have a maximum of 65046 extents. At first I didn't understand that this was an error message. After a while I realized that I was exceeding the maximum number of extents allowed in my configuration. Son instead of specifying by size, let's specify by number of extents:
   
   lvcreate -l 65046 -n share fileshare
   
   Now I have a logical volume of about 250GB.
   


7. Format your new logical volume:
   
   mkfs.ext3 /dev/fileshare/share
   Note: you could fdisk this then format the partition you create, but is that really necessary... In our case I'll just format the whole thing and not fdisk it.
   
   (formatting this much takes a few minutes...)
   


8. mkdir and /etc/fstab:
   
   Make a directory to mount your logical volume and add an appropriate entry into /etc/fstab.
   
   mkdir /storage vi /etc/fstab

   /dev/fileshare/share    /storage                ext3    defaults        1 2
   



9. Make a new initrd that loads lvm-mod.o:
   
   First I tried the old "mkinitrd" (RH80) but soon realized it didn't have knowledge about lvm-mod.o.
   
   I then tried using lvmcreate_initrd to make the new initrd, but that appeared totally broken to me -- it complained about lack of space in the ramdisk.
   
   I knew this was a simple task so I decided to modify my existing initrd:
   
   What has to be done is the following 2 tasks:
   
   
   • add 1 file (lvm-mod.o) to initrd.img/lib/
   • add 2 lines to initrd.img/linuxrc so it will load lvm-mod.o
   
   Here's the steps on modifying the initrd - more info available here: rhdiskmod.html
   
   
   1. mkdir /tmp/initrd
   2. cd /tmp/initrd
   3. cp -a /boot/initrd-2.4.18-14smp.img .
   4. mv initrd-2.4.18-14smp.img initrd-2.4.18-14smp.img.gz
   5. gunzip initrd-2.4.18-14smp.img.gz
   6. mkdir 1
   7. mount initrd-2.4.18-14smp.img 1/ -o loop
   8. cp -a /lib/modules/2.4.18-14smp/kernel/drivers/md/lvm-mod.o 1/lib/
   9. vi 1/linuxrc
   You'll see something like the following - in bold I've already inserted my load lvm-mod changes just prior to jbd.o and ext3.o:

   echo "Loading scsi_mod module"
   insmod /lib/scsi_mod.o
   echo "Loading sd_mod module"
   insmod /lib/sd_mod.o
   echo "Loading cciss module"
   insmod /lib/cciss.o
   echo "Loading lvm-mod module"
   insmod /lib/lvm-mod.o
   echo "Loading jbd module"
   insmod /lib/jbd.o
   echo "Loading ext3 module"
   insmod /lib/ext3.o
   

   Then I repacked the initrd and added it to grub:
   10. umount 1/
   11. gzip -n -9 initrd-2.4.18-14smp.img
   12. rmdir 1/
   13. mv initrd-2.4.18-14smp.img.gz /boot/initrd-2.4.18-14smp.img-lvm
   14. cd /tmp
   15. rmdir /tmp/initrd
   16. vi /boot/grub/grub.conf
   Here's my changes to grub -- new section in bold:
   

   default=0
   timeout=10
   splashimage=(hd0,0)/grub/splash.xpm.gz
   title Red Hat Linux (2.4.18-14smp) - lvm
           root (hd0,0)
           kernel /vmlinuz-2.4.18-14smp ro root=LABEL=/
           initrd /initrd-2.4.18-14smp.img-lvm
   title Red Hat Linux (2.4.18-14smp)
           root (hd0,0)
           kernel /vmlinuz-2.4.18-14smp ro root=LABEL=/
           initrd /initrd-2.4.18-14smp.img
   title Red Hat Linux-up (2.4.18-14)
           root (hd0,0)
           kernel /vmlinuz-2.4.18-14 ro root=LABEL=/
           initrd /initrd-2.4.18-14.img
   

10. Done. You can mount now with "mount -a" or it will come up on a reboot too.

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Shrinking a logical volume

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Extending a logical volume