Managing Serviceguard A.11.20, March 2013

5. Create shared storage for a LVM volume group with mirroring for use by cluster packages.
cmpreparestg –l <vgname> –p <pv_path> ... –n <node1> –n <node2>
<vgname> is the path name of the volume group that is to be created and imported to each
specified node, and each <pv_path> is the name of a physical volume on the local node
from which the volume group specified by <vgname> is to be created.
For example, suppose that /dev/cdisk/disk12 and /dev/cdisk/disk13 are two
physical devices on the primary SCSI bus or adapter, and /dev/cdisk/disk14 and /dev/
cdisk/disk15 are two physical devices on a secondary bus or adapter, and you want the
devices on the secondary bus to contain PVG-strict mirror copies, proceed as follows.
a. cmpreparestg –l /dev/vgdatabase –p /dev/cdisk/disk12 –p /dev/
cdisk/disk13 –p /dev/cdisk/disk14 –p /dev/cdisk/disk15 –n ftsys9
–n ftsys10
This configures physical devices /dev/cdisk/disk12 and /dev/cdisk/disk13
on the primary bus, and /dev/cdisk/disk14 and /dev/cdisk/disk15 on the
secondary bus, into the volume group /dev/vgdatabase, and imports the volume
group on the non-local node in the cluster created in step b.
b. Edit /etc/lvmpvg on node1 and node2 so the relevant portion now reads as follows:
VG /dev/vgdatabase
PVG bus0
/dev/cdisk/disk12
/dev/cdisk/disk13
PVG bus1
/dev/cdisk/disk14
/dev/cdisk/disk15
NOTE: If you are not using cDSFs, you may need to change the DSF names to make
sure that the DSF names point to the same physical storage on each node. If you are
using cDSFs, the names are guaranteed to be the same.
c. cmpreparestg –l /dev/vgdatabase –L –o lv_opts=”-L 120 –m 1 –s g”
–o fs_opts=”-F vxfs” –m /newdir –n ftsys9 –n ftsys10
This configures the logical volume /dev/vgdatabase/lvol<n> with PVG-strict mirroring
from the disks on the primary bus (bus0, disks /dev/cdisk/disk12 and /dev/cdisk/
disk13) to those on the secondary bus (bus1, disks /dev/cdisk/disk14 and /dev/
cdisk/disk15). LVM supplies the logical volume number (<n>).
This command also builds a VxFS file system on the logical volume, and mounts it to /newdir.
If the logical volume will be used for raw storage (for example for a database) omit the fsopts
and –m options; for example:
cmpreparestg –l /dev/vgdatabase –L –o lv_opts=”-L 120 –s g” –n ftsys9
–n ftsys10
You can also create a shared storage for a VxVM/CVM disk group for use by cluster packages.
For example, suppose that /dev/disk/disk39 and /dev/disk/disk40 are two physical
devices and you want to create a VxVM/CVM disk group and configure a logical volume
with mirroring across the two disks, use the cmpreparestg command as follows:
cmpreparestg –g dg_sat –p /dev/disk/disk39 –p /dev/disk/disk40 –L
lvol1 –o lv_opts=”100M layout=mirror nmirror=2” –o fs_opts=”-F vxfs”
–m /mnt1
This command creates a VxVM/CVM disk group with name dg_sat and create a logical
volume lvol1 with mirroring across the two disks /dev/disk/disk39 and /dev/disk/
disk40.
170 Building an HA Cluster Configuration