How to Create Disk on VA7100

[Steven Chen_1]

Hello,

We have a VA7100 and I have created 4 LUNs. I would like to know how to proceed from there, i.e. how to pv, lv create, etc.

It seems confusing without manual for guidance. Don't know why HP does not ship it along with the VA.

The VA config is 0/4/0/0 is primary, while 0/7/0/0 is alternate. 0/7/0 goes to disk of c6txdx, while 0/4/0 goes to c4txdx.

The followings are what I have and really would like guru give comments on it:

-----------------------------Sequences:

a. Create LUN (lun 0 =10m, first lun is for system communication only, never use it)
b. Ioscan ???fn
c. Insf ???eH /0/4/0/0, insf ???eH 0/7/0/0 (if ioscan do not see disks created)
d. Ioscan ???fn (again) 0/4/0 primary c4txdx, 0/7/0 alternate c6txdx
e. Mkdir vgxx
f. Mknod vg group
g. Pvcreate /dev/rdsk/c4txdx
h. Vgcreate vgxx /dev/dsk/c4/txdx, ??? (more volumn groups smaller than 10G
i. Vgchange ???a y vgxx
j. Vgextend /vgxx /dev/dsk/c6txdx,??? (c6 always extends)
k. Vgdisplay ???v vgxx (should show both c4 and c6)
l.
-----------------------

My major confusion lies with:

1) pvcreate only on c4txdx, not on c6txdx?
2) vgextend only on c6txdx, not on c4txdx?

Help will be very appreciated.

Steven

[Tom Danzig · Accepted solution]

Since c4t1d1 and c6t1d1 point to the same physical LUN (via separarte channels), only the one pvcreate is needed.

The vgextend on the "alternate" path to the LUN adds the failover path to LVM. The primary was added via the vgcreate on the primary path to the LUN.

[Ted Ellis_2]

you can even skip the vgextend altogether and just create the volume group with the alternate link using vgcreate:

vgcreate /dev/vgxx /dev/dsk/c6txdx /dev/dsk/c4txdx

this will automatically create the volume group with c6txdx as primary path and c4txdx as alternate...

after the initial pvcreate on one of the paths

Ted

[S.K. Chan]

It seems you feel comfortable creating the LUNs and ioscan part, so I won't go there. Lets take an example (c4t0d2 as primary and c6t1d2 as secondary). Say you want to create lvol1 (4GB) in vg01.
# mkdir /dev/vg01
# mknod /dev/vg01/group c 64 0x020000
==> Minor number 0x020000 must be unique.
# pvcreate /dev/rdsk/c4t0d2
==> Only do this on the primary device.
# vgcreate /dev/vg01 /dev/dsk/c4t0d2 /dev/dsk/c6t1d2
==> You don't need step (i), when a VG is created it's automatically activated. The vgcreate command will know c4t0d2 is primary and c6t1d2 is the alternate path. There is no need to run pvcreate on the alternate device/path. This way you do not need an extra step (ie the vgextend).
# vgdisplay -v /dev/vg01
==> You should see right at the bottom "Alternate Path" tagged to c6t1d2.
# lvcreate -L 4000 -n lvol1 /dev/vg01
==> Creating a 4GB LV.
# newfs -F vxfs /dev/vg01/rlvol1
==> Format it as vxfs filesystem
# vi /etc/fstab
==> Edit "fstab" file to make the mount point permanent.

If you want you can simply switch the primary and alternate device.. (just to show you..)
# vgreduce /dev/vg01 /dev/dsk/c4t0d2
==> Take c4t0d2 out from vg01. Now c6t1d2 automatically becomes the primary link.
# vgextend /dev/vg01 /dev/dsk/c4t0d2
==> Extend vg01 by putting c4t0d2 back to it, hence it's now the alternate link.

[Steven Chen_1]

Thanks a lot for S.K. and all others who offer decent help.

For the final touch-up, I would like to know what to put into the /etc/fstab.

I have non-VA entry like:

----------------------------
/dev/vg02/lvol1 /disk2 vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg03/lvol1 /disk3 vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
------------------------------

With VA, what would be the proper entry? For the "nolargefiles" generated by sam before should have problem when I have the lvol1 size = 15G.

Steven

[S.K. Chan]

You can put the same entry like what you've shown. If you choose to implement "largefiles" option, ie if you run your newfs like so ..
# newfs -F vxfs -o largefiles /dev/vg01/rlvol1
then you need to put "largefiles" in place of the "nolargefiles" in the "fstab" file. Also take a look at all other options available for mounting a vxfs FS.
# man mount_vxfs