setup of vg00 for two 72gig mirrored internal disks.

[Steve Post]

Fast, simple question.
I'm used to disks being 4 or 8 gigs, not 72 or 300 gigs.

It looks like I'll be getting a box where vg00 is supposed to setup mirrored over two 72 gig disks.

If I just set it up like normal, I'm sure the number of Physical Extents per Physical volume (max_pe), would far exceed what's allowed.

I'm guessing I would change the size of the physical extents to 16megs (instead of the default 4megs per extent).

I also would lower the number of physical volumes allowed per volume group from 16 to 8.

I got this idea from looking at technical knowlege base documents: KBRC00004285, KBRC0009036, KBRC00001020, KBRC00000716, and LVMKBRC00006254

I'm sure somebody out there already has a box like this. How did YOU set up vg00? Which parameter did YOU change?

max_pe: maximum number of physical extents per physical volume

max_pv: maximum number of physical volumes (disks) per volume group (bucket of disks).

pe_size: number of megs per extent.

max_lv: maximum number of logical volumes per volume group.

steve
Version of hpux? I'm assuming 11i v2, EOE.

[Mel Burslan]

Steve,

As all of my new keystone servers, i.e., rpXXXX machines, are coming with these drives for the past year or so, I had to build the OS, hence the VG00 on these disks. And the OS installation takes care of the creation of the vg00 for you, using all of the available disk capacity.

HTH

[DCE]

Vgcreate is an interesting little program - when you first create a volume group, it evaluates the disks and sets up the volume group parameters so it can use all the space on all the disks. This can be a double edges sword though. You are limited to using disks no larger than what was available at vg creation time when you add disks to the vg. If you forsee adding larger disks to the vg in the future, then you should manually adjust the parameters

[Steve Post]

Let me rephrase the question.

I'm looking for the result of "vgdisplay -v" on a computer with this setup:

two 72gig mirrored drives for vg00

some very big drives like the size 360gigs.

[Patrick Wallek · Accepted solution]

I have just set up 2 new rp4440's with 73GB disks on VG00 with HP-UX 11.11 EOE. The same should hold true for 11iv2 as well.

Here is the 'vgdisplay -v vg00' output from one of those machines. This will also show you the LV sizes I used as well.

# vgdisplay -v vg00
--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 24
Cur LV 8
Open LV 8
Max PV 6
Cur PV 2
Act PV 2
Max PE per PV 10000
VGDA 4
PE Size (Mbytes) 32
Total PE 4374
Alloc PE 1204
Free PE 3170
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 20
Used PV 2

LV Name /dev/vg00/lvol2
LV Status available/syncd
LV Size (Mbytes) 2048
Current LE 64
Allocated PE 128
Used PV 2

LV Name /dev/vg00/lvol3
LV Status available/syncd
LV Size (Mbytes) 512
Current LE 16
Allocated PE 32
Used PV 2

LV Name /dev/vg00/lvol4
LV Status available/syncd
LV Size (Mbytes) 2048
Current LE 64
Allocated PE 128
Used PV 2

LV Name /dev/vg00/lvol5
LV Status available/syncd
LV Size (Mbytes) 4096
Current LE 128
Allocated PE 256
Used PV 2

LV Name /dev/vg00/lvol6
LV Status available/syncd
LV Size (Mbytes) 2048
Current LE 64
Allocated PE 128
Used PV 2

LV Name /dev/vg00/lvol7
LV Status available/syncd
LV Size (Mbytes) 4096
Current LE 128
Allocated PE 256
Used PV 2

LV Name /dev/vg00/lvol8
LV Status available/syncd
LV Size (Mbytes) 4096
Current LE 128
Allocated PE 256
Used PV 2


--- Physical volumes ---
PV Name /dev/dsk/c2t0d0
PV Status available
Total PE 2187
Free PE 1585
Autoswitch On

PV Name /dev/dsk/c2t1d0
PV Status available
Total PE 2187
Free PE 1585
Autoswitch On

[Orhan Biyiklioglu]

These values are from a production server with 2 72GB mirrored disks:

It is running HP-UX 11.23

max_pe: 4328
max_pv: 16
pe_size: 16
max_lv: 255

Excerpt from man vgcreate:

The default value for max_pe is 1016. However, if the size of any physical volume exceeds 1016 times the pe_size, the default value for max_pe is adjusted to match the physical volume size. The maximum number of physical extents can be a value in the range 1 to 65535.

hth

[Orhan Biyiklioglu]

2 146GB disks mirrored on HP-UX 11.23

[hostname:/]# vgdisplay vg00
--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 9
Open LV 9
Max PV 16
Cur PV 2
Act PV 2
Max PE per PV 4356
VGDA 4
PE Size (Mbytes) 32
Total PE 8692
Alloc PE 1129
Free PE 7563
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

[Steve Post]

yep. That's what I'm looking for.
I see the size of the extents was increased. It figured that had to be the right thing to do. But I wanted a better opinion than ME.

I might have five 72gig disks look like one really big disk. If that is the case, I would have 92160 four meg extents on one disk. This is above the 65535 limit.

I tried the little math formula from the hp documents. I probably did it wrong. It told me I should have 180megs per physical extent. I expected it should really be in a factor of 2, (like 16, or 32 megs).

thanks.

[Alzhy]

We use a minimalist OS partitioning approach and name the lvols accordingly:

/dev/vg00/stand as /stand -- 512MB
/dev/vg00/root as / -- 8GB
/dev/vg00/swap -- 8 to 32GB (or equal to RAM)
/dev/vg00/opt as /opt -- 8GB
/dev/vg00/var as /var -- 16GB
/dev/vg00/tmp as /tmp -- 4GB
/dev/vg00/r as /r --- whatever the balance

/r we use for things like logs, root account home, etc..


Outside of VG00, we use VxVM 3.5 on our 11.11 systems, VxVM 4.1 on upcoming 11.23 systems.

[Devender Khatana]

Hi,

The parameter taken from a running configuration will only allow you to create a VG allowing only 72GB disks in it to be used effectively. If you intend to use larger disks after some time and want to prepare your VG now itself for that then you should readjust these parameter to atleast for double size disks.

Allthough if not changed manually the parameters will be by default set to the minimum value required to the whole space of that disks.

Max PE per PV 10000
PE Size (Mbytes) 32

Also the formula for this require to increase the PE Size alongwith Max PE Per PV. The values given by Patrick are quite enough to accomodate the disks of sizes upto approx. 320GB.

HTH,
Devender

[Devender Khatana]

Hi,

Attached is the file describing the value of PE Size to be increased when Max_PE_PER_PV is huge.

HTH,
Devender

[Steve Post]

attached was a question written by someone with a lot of sarcastic wit.....HEY. I wrote this.
I'm the only guy I know that would would rename an HP application to "Bob" because it's name changed too many times.

[Tim Sanko]

I might suggest if this is a larger system
(many hypers or metas from an EMC or many drives from a Hitachi) that you follow this guideline.
72 GB drive may well be carved up as follows:

/ at 4GB (seems wastefull until you have 140 128 gb metas presented.) 68 gb free

Swap is 1.5 X expected end of life memory. 24GB for 16GB system 44 GB free

/var= 1.5X memory 24 GB for foom for a crash dump. (16 GB system) 20 GB free
****/var/adm/sw/save can get BIG...****

/usr as needed (4 gb)16 GB free

/tmp as needed (2 GB) 14 GB FREE

The unused can be left to be allocated later or used as needed to increase the size of a mount point.

Tim

[Tim Sanko]

By the way, I have an rp7420 configured like this... I have not had anything near to a space problem anywhere except when I had a crash to send off to HP...

Tim

[Steve Post]

ok. Thanks for the info.
Whenever I get an answer, I also check the person's profile.

I see you work just south of Akron Ohio? I work in Stow and live in Kent.

[Tim Sanko]

I live in Canton and work in Barberton. I am in Canton phone book. Give me a ring...

Tim