GFS2 Cluster in VMware

From Linux NFS

VMware

• bought a copy of VMware Workstation 6, installed it on my T-43 Thinkpad "atro"(running openSuSE 10.2, 2GB of RAM).
• made a new virtual machine: OS: Linux, Version: "Other Linux 2.6.x kernel", Networking: Bridged, Disk: 4GB, split into 2GB files, RAM: 256MB
• installed Fedora 8 in it -- even X worked well with only 256MB of RAM(!) -- guest is named "guest1"
• yum-installed gfs2-utils and libvolume_id-devel (i also tried cman, cman-devel, openais, openais-devel, and lvm2-cluster, but even they were out-of-date with the stock Fedora kernel, and so are also too old for the pNFS kernels)
• downloaded and installed device-mapper-1.02.22, openais-0.80.3, cluster-2.01.00, and lvm2-2.02.28

ATA over Ethernet (for guest cluster shared storage)

• yum-installed AoE initiator (client) aoetools-18-1 on guest1
• downloaded AoE target (server) vblade-15.tgz and installed it on atro
• i set aside a spare partition on atro to export as a block device over AoE:
  • [atro] $ sudo ln -s /dev/sda6 /dev/AoE
  • [atro] $ sudo vbladed 0 1 eth0 /dev/AoE (major dev num 0, minor 1)
  • [guest1] $ sudo modprobe aoe
    • .. AoE discovers all exported devices on the LAN; mine was the only one, and immediately appeared as /dev/etherd/e0.1. Mounting it "just worked"; props to AoE!

LVM and GFS2 setup

• prep physical volume for LVM:
  • [guest1] $ sudo pvcreate -M 2 /dev/etherd/e0.1
• create the volume group GuestVolGroup and add all of the AoE "device" to it:
  • [guest1] $ sudo vgcreate -M 2 -s 1m -c y GuestVolGroup /dev/etherd/e0.1
• edit /etc/lvm/lvm.conf and make sure to set locking_type to DLM
• before further stuff can proceed, the cluster needs to be up and clvmd needs to be running everywhere. So, in VMware I cloned guest1 twice: as guest2 and guest3.
• edit /etc/cluster.conf and name the cluster GuestCluster and set up the three nodes with manual (read: ignored) fencing.
• bring up the cluster:
  • $ pdsh -w guest[1-3] sudo service cman start && pdsh -w guest[1-3] sudo service clvmd start
• create the logical volume GuestVolume and assign the full volume group to it:
  • [guest1] $ sudo lvcreate -n GuestVolume -l 100%VG
• .. and make a GFS2 fs therein:
  • [guest1] $ sudo gfs2_mkfs -j 3 -p lock_dlm -t GuestCluster:GuestFS /dev/GuestVolGroup/GuestVolume
• restart the daemons, then mount and your VMware GFS2 cluster should be good to go! :)

Adding disk space to an LVM'ed VMware guest

Having blithely thought that 4GB of disk space per guest (which Fedora LVMs as VolGroup00) would be sufficient, I then git-cloned my repo and then didn't have enough space to build my kernels; gak. (Since I'm building things on just one guest and then cloning it, I'm hoping that maybe I can somehow shrink the cloned guests' disks back down to just 4GB.)

• in VMware, I went to Edit Virtual Machine Settings -> Add (device). I created a (virtual) SCSI disk, 3GB, allocate on-demand, and added it to my guest.
  • after starting the guest, the disk appeared as /dev/sdb
• create a single partition using the entire device:
  • [guest1] $ fdisk # etc etc NB: make sure that the partition type is 0x8e (Linux LVM)
• make a single LVM physical volume on it:
  • [guest1] $ pvcreate -M 2 /dev/sdb1
• extend the existing volume group by adding the prepped physical volume:
  • [guest1] $ vgextend VolGroup00 /dev/sdb1
• extend the logical volume to use the entire (now-larger) volume group:
  • [guest1] $ lvextend -l +100%FREE /dev/VolGroup00/LogVOl00
• Inspect things with pvs, vgs, and lvs
• extend the filesystem itself within the logical volume (it can handle online resizing):
  • [guest1] $ resize2fs /dev/VolumeGroup00/LogVol00

At this point, hopefully df -k should show you a larger volume :)