VxVM DMP on XP Storage

[Alzhy]

Has anyone widely used VxVM DMP as the path protection/I/O load balancing solution for XP Arrays? And what your experiences are? On Sun's - this has been our norm of operation as it supports active/active mode (mode 9 on the HDS)

We do not intend to use AutoPath(now called SecurePath since SecurePath 3.0D) and just use VxVM DMP.

[Sanjay_6]

Hi Nelson,

Maybe this link might help,

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062923016

The itrc doc id is VxVM057.

Hope this helps.

Regds

[Chris Huys_2 · Accepted solution]

Hi Nelson,

> Has anyone widely used VxVM DMP as the
> path protection/I/O load balancing
> solution for XP Arrays?
Yes. ;-)

> And what your experiences are?
Not bad. ;-)

Recommendations :

* install the current VxVM 3.5 patches on all of youre HP-UX hosts which are using VxVM.

current vxvm 3.5 patches for HP-UX 11.11

PHKL_30756 s700_800 11.11 VxVM 3.5m Kernel Cumulative Patch 06
PHCO_30850 s700_800 11.11 VxVM 3.5m Command Cumulative Patch 07
PHKL_31162 s700_800 11.11 crash,vpars,timeout;SG TOC,nParCnfg,shutdown

PHCO_31203 s700_800 11.11 VERITAS VM Mgmt Service Provider Patch 03

* install the (needed for vxvm dmp), latest support library, or ASL, for youre diskarray from http://ftp.support.veritas.com/pub/support/products/VolumeManager_UNIX/

* avoid using lun 0,8,16,.. as dataluns on the XP. These luns are "placeholder" luns on HP-UX hosts. In ioscan they will show up, with the description DISK-SUBSYSTEM. Its best, to keep it this way.

And for the rest have a lot of fun, with the XP diskarray and vxvm. ;-)

Greetz,
Chris

[Alzhy]

Thanks again Chris.

I am fully aware of the needed command and cummulative patches. But have you had "special" point patches in the past that was released by Veritas/HP specifically for your site? And what did it address?

As far as best practices:

1. Do you have a naming convention for disks (aka "dm" - disk media record names?) specific for the XP?

2. Do you use 7+1P or 3+1P on your RAID5 Array groups?

3. How do you stripe? 4-way with each member LUN coming from an array group contained on a different DKU (array frame) AND presented on different HBAs? I know this varies but how wide are your srtipe sizes?

4. Do you employ layered volumes (ie. stripe of stripes, etc..) to create even more high performing volumes?


Thanks a lot sir!

[Chris Huys_2]

> I am fully aware of the needed command
> and cummulative patches. But have you
> had "special" point patches in the past
> that was released by Veritas/HP
> specifically for your site? And what did
> it address?

Im a HP support engineer focussed on VxFS/VxVM/VCS support on all OSplatforms (not only HP-UX ;-)) , in the europe region.

Ive sent in the past some Veritas (HP-UX) pointpatches to customers. However Im not aware of any current pointpatches that are available. The latest one, Ive sent included the fix, (SR: 8606377252 CR: JAGaf37530 ), that is now included in PHKL_30756.

> 3+1P or 7+1P

Im not a XP support engineer, but I asked one and he says, if its for performance take, 7+1P.

> naming convention.

I would keep it simple.
disk1 of = 01
disk2 of = 02, etc...


> 3. How do you stripe? 4-way with each
> member LUN coming from an array group
> contained on a different DKU (array
> frame) AND presented on different HBAs? I
> know this varies but how wide are your
> srtipe sizes?
> 4. Do you employ layered volumes (ie.
>stripe of stripes, etc..) to create even
> more high performing volumes?

Ah, more performance related questions. And the eternal answer is, it depends.
It depends on the application/OS/volume manager and diskarray.

So for that I would, need to point, you to a performance consultant, who has knowledge about all these things. ;-)

Greetz,
Chris