Creating a Veritas Volume Manager volume from a plex


While cleaning up my Veritas VxVM notes this week, I came across one of my cheat sheets for creating volumes from plexes. This can be useful when you want to perform an offline backup of the data on an alternate server, or when you want to grab a spare copy of data prior to performing a major change. To create a new volume from a plex, you will first want to stash a copy of the vxprint output somewhere:

$ /usr/sbin/vxprint -hmQq > HOME/vxprint.restore

Once you make a backup, you will want to run the human consumable form of vxprint to see which devices are available:

$ /usr/sbin/vxprint -hft

Disk group: oradg

DG NAME NCONFIG NLOG MINORS GROUP-I
ST NAME STATE DM_CNT SPARE_CNT APPVOL_CNT
DM NAME DEVICE TYPE PRIVLEN PUBLEN STATE
RV NAME RLINK_CNT KSTATE STATE PRIMARY DATAVOLS SRL
RL NAME RVG KSTATE STATE REM_HOST REM_DG REM_RLNK
CO NAME CACHEVOL KSTATE STATE
VT NAME NVOLUME KSTATE STATE
V NAME RVG/VSET/CO KSTATE STATE LENGTH READPOL PREFPLEX UTYPE
PL NAME VOLUME KSTATE STATE LENGTH LAYOUT NCOL/WID MODE
SD NAME PLEX DISK DISKOFFS LENGTH [COL/]OFF DEVICE MODE
SV NAME PLEX VOLNAME NVOLLAYR LENGTH [COL/]OFF AM/NM MODE
SC NAME PLEX CACHE DISKOFFS LENGTH [COL/]OFF DEVICE MODE
DC NAME PARENTVOL LOGVOL
SP NAME SNAPVOL DCO

dg oradg default default 10000 1127240283.19.winnie

dm c1t1d0 c1t1d0s2 auto 2048 35521408 -
dm c1t2d0 c1t2d0s2 auto 2048 35521408 -
dm c1t3d0 c1t3d0s2 auto 2048 35521408 -
dm c1t4d0 c1t4d0s2 auto 2048 35365968 -
dm c1t5d0 c1t5d0s2 auto 2048 35521408 -
dm c1t6d0 c1t6d0s2 auto 2048 35521408 -

v oravol01 - ENABLED ACTIVE 20971520 SELECT - fsgen
pl oravol01-01 oravol01 ENABLED ACTIVE 20971776 STRIPE 3/128 RW
sd c1t1d0-01 oravol01-01 c1t1d0 0 6990592 0/0 c1t1d0 ENA
sd c1t2d0-01 oravol01-01 c1t2d0 0 6990592 1/0 c1t2d0 ENA
sd c1t3d0-01 oravol01-01 c1t3d0 0 6990592 2/0 c1t3d0 ENA
pl oravol01-02 oravol01 ENABLED ACTIVE 20971776 STRIPE 3/128 RW
sd c1t4d0-01 oravol01-02 c1t4d0 0 6990592 0/0 c1t4d0 ENA
sd c1t5d0-01 oravol01-02 c1t5d0 0 6990592 1/0 c1t5d0 ENA
sd c1t6d0-01 oravol01-02 c1t6d0 0 6990592 2/0 c1t6d0 ENA

After you locate the plex you want to turn intoa volume, you will need to disassociate it from the volume with the vxplex utility:

$ vxplex dis oravol01-02

Once the plex has been disassociated, you can then turn it into a volume with the vxmake utility:

$ vxmake -U gen vol oravol02 plex=oravol01-02

After the volume is created, you can start it and mount it just like all of the other volumes on your server:

$ vxvol start oravol02

$ mount -F vxfs /dev/vx/dsk/oradg/oravol02 /mnt

$ ls -la /mnt

total 8388690
drwxr-xr-x 3 root root 8192 Oct 30 21:01 .
drwxr-xr-x 37 root root 1024 Oct 27 12:27 ..
drwxr-xr-x 2 root root 96 Oct 27 12:25 lost+found
-rw------T 1 root root 1073741824 Oct 30 20:59 oradata01.dbf
-rw------T 1 root root 1073741824 Oct 30 21:00 oradata02.dbf
-rw------T 1 root root 1073741824 Oct 30 21:01 oradata03.dbf
-rw------T 1 root root 1073741824 Oct 30 21:03 oradata04.dbf

This is a nifty feature, and now that Veritas Volume Manager and File System are free (thanks for the link CW!), you can test it out in your favorite lab!

This article was posted by Matty on 2006-05-17 10:35:00 -0400 EDT