Mirroring a Concatenated Volume to a Striped Volume

[Roland Rebstock_1]

All, in LVM can I create a striped mirror of a concatenated logical volume. We would like to rebuild the volume as a stripe for performance reasons. I have done this with Veritas Volume Manager & Solaris by creating a striped volume and attaching the Striped/Mirrored plex to the concatenated volume and then disconnect the Concatendated volume but am unsure how to do this in LVM.

[Steven E. Protter]

Mirror/UX will not do striped mirroring.

You either stripe or mirror.

I've seen that posted a lot, so confidence is high. I only mirror, raid 1, so I've never tried.

SEP

[Patrick Wallek]

LVM does not support striping (-i and -I options to lvcreate) and mirroring EXCEPT by using extent-based stripes (-D option to lvcreate).

# man lvcreate

For more details.

If you want to stripe and mirror with HP-UX, you'll have to invest in Veritas Volume Manager for HP-UX.

[Roland Rebstock_1]

I hope there is a way, its alot easier to let the OS sync up the data then CPIO/Tar/backup/restore the data to a new volume.

[G. Vrijhoeven]

Hi,

Not sure if this is possible. Mirroring take place within one volumegroup. I would go for a new striped volumegroup and a fbackup and frecover.
May be s.o. else knows a way.

Regards,

Gideon

[Tim D Fulford]

I too would like to do what you ask... I need a testbed to see if it works!!

basicaly I have a non-mirrored LV on one disks and want to mirror and stripe it over 8 disks.. My plan .. and this is UNTESTED and may not work..

0 - make sure my /etc/lvmpvg contains two groups of disks
VG vgdb
PVG primary
/dev/dsk/c0t8d0
/dev/dsk/c1t9d0
/dev/dsk/c0t10d0
/dev/dsk/c1t11d0
PVG mirror
/dev/dsk/c1t8d0
/dev/dsk/c0t9d0
/dev/dsk/c1t10d0
/dev/dsk/c0t11d0

my original LV is called /dev/vgdb/data and exists on /dev/dsk/c0t8d0

1 mirror original LV onto a striped LV
lvextend -m 1 /dev/vgdb/data primary

2 reduce the original LV out
lvreuce -m 0 /dev/vgdb/data /dev/dsk/c0t8d0

3 mirror up the stripeed LV
lvextend -m 1 /dev/vgdb/data mirror

If this works I'll jump for joy as there is no down time required.. If not I plan to do the following
1 - create a mirrored striped LV
lvcreate -D y -s g -m 1 -n newdata -L 2048 vgdb
2 - stop database
3 - dd info from one LV to the other
dd if=/dev/vgdb/rdata bs=4096k of=/dev/vgdb/rnewdata
4 - rename newdata
mv /dev/vgdb/rdata /dev/vgdb/rolddata
mv /dev/vgdb/data /dev/vgdb/olddata
mv /dev/vgdb/rnewdata /dev/vgdb/rdata
mv /dev/vgdb/newdata /dev/vgdb/data
5 - start database
If 6 works delete olddata
lvreduce -f /dev/vgdb/olddata,
else backout!!!

Tim