Hello,
I'm working on a Xen solution where Xen's DomU are stored on iSCSI
volumes (a LV on Dom0 is a partition on DomU) to allow live migration
between hosts and to make DomU's partitions resizing easier.
iSCSI volumes -> LVM on Dom0 -> LV on Dom0 -> partition on DomU
As far as I know, I need CLVM in order to propagate automatically LVM
changes between host. So I've installed Ubuntu Gutsy on my server and
configured CMAN, CLVM and Open-ISCSI. Things seems to work fine.
I've also added some udev custom rules to have the same device name on
each box
----------------- udev rule
KERNEL=="sd*", BUS=="scsi", PROGRAM="iscsidev
%b",SYMLINK+="iscsi/%c{1}/lun%c{2}/part%n"
------------------
------------------ iscsidev
#!/bin/sh
BUS=${1}
HOST=${BUS%%:*}
# This was the first thing I thought of, I'm sure it can be done better:
LUN=`echo ${BUS} | cut -d":" -f4`
[ -e /sys/class/iscsi_host ] || exit 1
file="/sys/class/iscsi_host/host${HOST}/device/session*/iscsi_session*/targetname"
#target_name=$(cat ${file})
target_name=`cut -d":" -f2 ${file}`
# This is not an open-scsi drive
if [ -z "${target_name}" ]; then
exit 1
fi
echo "${target_name} ${LUN}"
--------------------------------------
Using these scripts my iSCSI devices have a symlink under /dev/iscsi/,
/dev/iscsi/IpponData.xen01/lun0/part is an example.
Next step, LVM initialization.
# pvcreate /dev/iscsi/IpponData.xen02/lun0/part
# pvdisplay /dev/iscsi/IpponData.xen02/lun0/part
--- NEW Physical volume ---
PV Name /dev/sdj
VG Name
PV Size 10.00 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID ecfUIs-4mnP-sKhq-mK8s-mICm-rUvt-2o8E8g
As you can see pvdisplay doesn't care about
/dev/iscsi/IpponData.xen02/lun0/part symlink and instead use the target
device.
This is a normal behavior? And when I will deploy CMAN, CLVM and iSCSI
on another box what will be LVM behaviours? I can't guarantee that
/dev/sdj will be accessible on the other box, only the symlink will be
the same.
--
Linux-cluster mailing list
Linux-cluster@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/linux-cluster
