disk mirroring

[David DiBiase]

I need some direction about disk mirroring. I have never implemented it and a new client wants us to use it. where do I start / download / read

[Pete Randall · Accepted solution]

http://h20293.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=B2491BA

The steps to mirror your boot volume are (PA-RISC):

1. Create a physical volume with a boot reserved area
"pvcreate -B /dev/rdsk/c1t6d0"

2. Add the physical volume to the root VG
"vgextend /dev/vg00 /dev/dsk/c1t6d0"

3. Use mkboot to place the boot utilities in the boot area and add the AUTO file
"mkboot /dev/rdsk/c1t6d0"
"mkboot -a "hpux -lq" /dev/rdsk/c1t6d0"

4. Use mkboot to update the AUTO file on the primary boot disk
"mkboot -a "hpux -lq" /dev/rdsk/c0t6d0"

5. Mirror the stand, root and swap logical volumes
"lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c1t6d0"
"lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c1t6d0"
"lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c1t6d0"

6. Modify your alternate boot path
"setboot -a 8/8.6.0 # use the path of your new boot disk"

7. Edit /stand/bootconf and add your new mirrored boot disk.

That's all there is to it. You may notice that I left out any
lvlnboot commands. That is because they are not
necessary - see the man page:

"This command should be run in recovery mode (-R)
whenever the configuration of the root volume group is
affected by one of the following commands: lvextend,
lvmerge, lvreduce, lvsplit, pvmove, lvremove, vgextend,
or vgreduce (see lvextend(1M), lvmerge(1M), lvreduce(1M),
lvsplit(1M), pvmove(1M), lvremove(1M), vgextend(1M), and
vgreduce(1M)). Starting with HP-UX Release 10.0, this is
done automatically."


For Itanium architecture, follow this guide:
http://h21007.www2.hp.com/dspp/tech/tech_TechSingleTipDetailPage_IDX/1,2366,5343
,00.html
-or-
http://docs.hp.com/en/B2355-90950/ch06s02.html#cchgjafa


Pete

[Bill Hassell]

And before you start, verify that the extra cost mirroring software has been installed:

swlist -l product | grep -i mirror

If nothing is found, you'll have to purchase the software and install it first.

[Steven E. Protter]

Shalom,

vxvm or lvm?

vxvm will let you mirror rootvg.

lvm requires add in software.

My lvm mirror procedure since I oppose vxvm on religious grounds(joke)

pvcreate -B /dev/rdsk/c1t0d0 #use real disk

mkboot -l /dev/rdsk/c1t0d0
mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/rdsk/c1t0d0 # use real disk


# mkboot -b /usr/sbin/diag/lif/updatediaglif -p ISL -p AUTO -p HPUX -p PAD -p LABEL /dev/rdsk/c?t?d?

If you are running 64-bit OS:

# mkboot -b /usr/sbin/diag/lif/updatediaglif2 -p ISL -p AUTO -p HPUX -p PAD -p LABEL /dev/rdsk/c?t?d?


vgextend /dev/vg00 /dev/dsk/c1t0d0 # same thing
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c1t0d0

# real disk. repeat for other lvols

lvlnboot -r /dev/vg00/lvol3 # root fs /
lvlnboot -s /dev/vg00/lvol2 #swap
lvlnboot -d /dev/vg00/lvol2 #swap/dump
lvlnboot -b /dev/vg00/lvol1
lvlnboot -R
lvlnboot -v
setboot
setboot -a 52.1.0 # second disk

SEP

[David DiBiase]

thanks - you must have known that my client would ask for both platforms since your responses are looking at both parisc and intel. They just asked me for 64-bit next quarter. I forgot to mention all file systems on my rp4440 (except stand) are VxFS. Do I have to do something about /stand? Should I (the client) by the Mirroring add-on feature?

SEP - I am looking for "easy" to maintain and stable. could you elaborate on lvm vs. vxvm

[Bill Hassell]

The filesystems are VxFS, but the question is about the volume manager. LVM is the classic HP-UX (and IBM, Linux, etc) volume manager, quite simple to use, while VxVM is the Veritas volme manager which sysadmins on Solaris (and others) will know well. I believe that basic mirroring comes with the VxVM base product whereas an extra license is needed for additional features in VxVM.

[David DiBiase]

Thanks for all your help.

My client machine shows the following resaults below.
Based on this, I assume my volume manager is vxvm. That said do the step outlined by Pete or SEP need any modifications?


# swlist -l product | grep -i veritas
PHCO_29606 1.0 VERITAS VM Provider Patch for NBU 5.0
PHCO_30700 1.0 VERITAS File System Mgmt Srvc Provider Pa
tch
PHCO_30730 1.0 VERITAS Enterprise Administrator Srvc Pat
ch
PHCO_30731 1.0 VERITAS Enterprise Administrator Patch
PHCO_34348 1.0 VERITAS VM Mgmt Service Provider Patch 05

VRTSfspro 3.5-ga08 VERITAS File System Management Services P
rovider
VRTSob 3.0.2.261a VERITAS Enterprise Administrator Service
VRTSobgui 3.0.2.261a VERITAS Enterprise Administrator
VRTSvlic 3.00.007e VERITAS License Utilities
VRTSvmdoc 3.5m VERITAS Volume Manager Documentation
VRTSvmpro 3.5m VERITAS Volume Manager Management Service
s Provider
VRTSvxvm 3.5m Base VERITAS Volume Manager 3.5 for HP-UX

#

[Torsten.]

This does not indicating the use of VxVM.

Just run vgdisplay -v and post the results.

If the command gives you information bout vg00, you are using LVM at least for your boot disks ;-)

[David DiBiase]

thanks for the direction

here is the output of the vgdisplay

# vgdisplay -v
--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 18
Open LV 18
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 4384
VGDA 2
PE Size (Mbytes) 32
Total PE 4374
Alloc PE 3785
Free PE 589
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vg00/lvol1
LV Status available/syncd
LV Size (Mbytes) 320
Current LE 10
Allocated PE 10
Used PV 1

LV Name /dev/vg00/lvol2
LV Status available/syncd
LV Size (Mbytes) 4096
Current LE 128
Allocated PE 128
Used PV 1

LV Name /dev/vg00/lvol3
LV Status available/syncd
LV Size (Mbytes) 224
Current LE 7
Allocated PE 7
Used PV 1

LV Name /dev/vg00/lvol4
LV Status available/syncd
LV Size (Mbytes) 1024
Current LE 32
Allocated PE 32
Used PV 1

LV Name /dev/vg00/lvol5
LV Status available/syncd
LV Size (Mbytes) 32
Current LE 1
Allocated PE 1
Used PV 1

LV Name /dev/vg00/lvol6
LV Status available/syncd
LV Size (Mbytes) 2464
Current LE 77
Allocated PE 77
Used PV 1

LV Name /dev/vg00/lvol7
LV Status available/syncd
LV Size (Mbytes) 1248
Current LE 39
Allocated PE 39
Used PV 1

LV Name /dev/vg00/lvol8
LV Status available/syncd
LV Size (Mbytes) 4608
Current LE 144
Allocated PE 144
Used PV 1

LV Name /dev/vg00/lvol9
LV Status available/syncd
LV Size (Mbytes) 3008
Current LE 94
Allocated PE 94
Used PV 1

LV Name /dev/vg00/lvol10
LV Status available/syncd
LV Size (Mbytes) 10016
Current LE 313
Allocated PE 313
Used PV 1

LV Name /dev/vg00/lvol11
LV Status available/syncd
LV Size (Mbytes) 16000
Current LE 500
Allocated PE 500
Used PV 1

LV Name /dev/vg00/lvol12
LV Status available/syncd
LV Size (Mbytes) 16000
Current LE 500
Allocated PE 500
Used PV 1

LV Name /dev/vg00/lvol13
LV Status available/syncd
LV Size (Mbytes) 10016
Current LE 313
Allocated PE 313
Used PV 1

LV Name /dev/vg00/lvol14
LV Status available/syncd
LV Size (Mbytes) 10016
Current LE 313
Allocated PE 313
Used PV 1

LV Name /dev/vg00/lvol15
LV Status available/syncd
LV Size (Mbytes) 10016
Current LE 313
Allocated PE 313
Used PV 1

LV Name /dev/vg00/lvol16
LV Status available/syncd
LV Size (Mbytes) 12000
Current LE 375
Allocated PE 375
Used PV 1

LV Name /dev/vg00/lvol17
LV Status available/syncd
LV Size (Mbytes) 10016
Current LE 313
Allocated PE 313
Used PV 1

LV Name /dev/vg00/lvol18
LV Status available/syncd
LV Size (Mbytes) 10016
Current LE 313
Allocated PE 313
Used PV 1


--- Physical volumes ---
PV Name /dev/dsk/c3t0d0
PV Status available
Total PE 4374
Free PE 589
Autoswitch On


#

[Steven E. Protter]

Hi,

lvm is what I provided mirror procedure for.

VxVM is Veritas Volume Manager and if you choose to use it the mirror process is totally different.

LVM is the gold standard and many more people know it in the HP-UX world. This increases the chance of you taking a vacation without being interupted.

LVM is as stable as it gets, and the cost of mirror/ux is worth it in my view.

SEP

[inventsekar_1]

Hi David,
Regarding the comparison between lvm and veritas, u can find it in the VxVM migration guide.

http://docs.hp.com/en/5991-0609/index.html

This is not exactly what u asked, but it might give u some ideas:
VxVM and LVMâ Conceptual Comparison
http://docs.hp.com/en/5991-0609/ch01s02.html

As SEP told, LVM is the industry de-facto standard.
As per me, VxFS and VxVM is good for "online" operations. VxFS is advanced than LVM. but mirroring is not an "Advanced operation".

[Bill Hassell]

The vgdisplay shows that the root volume (vg00) is being managed by LVM and is currently not mirrored. Therefore, you'll need to purchase the optional Mirror/UX product to perform the mirroring. You can see if mirroring is installed very quickly with the command:

ll /sbin/lvsync

If nothing shows up, there is no mirroring software.

[Pete Randall]

The vgdisplay output also shows quite a few extra logical volumes other than the standard root file system of lvol1 (/stand) through lvol8 (/var - though /var could be lvol9 or greater if you have multiple swap areas. You will need to determine just what you want to mirror and how much space it will require.

As a general rule, it is routinely recommended to keep your data volumes separate from your root file systems - in their own separate volume group on their own disks. You might want to take a look at re-organizing everything properly.


Pete

[David DiBiase]

Thank you all for your help. I now have a starting point. Pete, your last point is well taken - mirroring or not. The machine I displayed is doing a data conversion where the resulting data base will be on a SAN and the FS structure shown is being used to transport the data.

If your ever in central NJ, the beer is on me.