LVM and VxVM

Can i use LVM for SAN disks and Veritas for root disks

 
jmckinzie
Super Advisor

Can i use LVM for SAN disks and Veritas for root disks

Team,

I currently have a server using VxvM for its cuurrent root disk and SAN disks. However, I like LVM much better...

I have just received 200GB of new san and would like to carve it up using LVM.

Can I do this? Why or Why not?

Should I do this? Why or Why not?
6 REPLIES 6
SoorajCleris
Honored Contributor

Re: Can i use LVM for SAN disks and Veritas for root disks

Hi,

==> Can I do this? Why or Why not?

Yes you can do this.

Should I do this? Why or Why not?

The answer is the same , when you answer, why you are using VxVm for rootdg.

Regards,
Sooraj

"UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity" - Dennis Ritchie
jmckinzie
Super Advisor

Re: Can i use LVM for SAN disks and Veritas for root disks

I inherited these hosts and they were previously built using VXvm.
SoorajCleris
Honored Contributor

Re: Can i use LVM for SAN disks and Veritas for root disks

from my experience, I have seen very rare cases people like to use vxvm for root.

There are advantages and disadvantages. There are more options avaialable when you go for VxVM for other volume groups/dgs other than root.

Somepeople believe more performance with VxFS and VCs as all products from Veritas.

YOu have options like RAID5 in VxVM.
but it creates more complication for a normal administrator. The result is you should learn one more product to manage it.

Regards,
Sooraj
"UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity" - Dennis Ritchie
Doug O'Leary
Honored Contributor

Re: Can i use LVM for SAN disks and Veritas for root disks

Hey;

You certainly *can* do this although it seems completely backwards to me.

1. vxvm on boot disks: In my opinion, bad idea. Veritas has been tied in with solaris boxes for, literally, decades; and you still hear cases where patching a box made it unbootable because vxvm got scrambled somehow. Fortunately, this seems fairly rare now, but still possible. HP hasn't enjoyed anywhere near that same timeframe of having vxvm booting their OS. Additionally, HP LVM is tied so much more deeply into the OS than either vxvm or disksuite is for solaris.

For that reason, I will always use LVM for the boot disk.

2. vxvm is a techologically superior LVM. Probably blasphemy in this forum, but nonetheless, accurate. It is more flexible, even with the changes to HPLVM that came with 11.31. You can do online reorganizations, mirror striped vols, stripe mirrored vols, etc.

That being said, it costs more - a lot more. I have supported any number of configurations with and without vxvm on the data disks for the better part of 6 years now. I can think of only a very few occasions (like maybe 6) where that flexibility made my life easier or would have made it easier had it been available.

There is a significant amount of logic that argues against mixing LVMs on your data disks. Using one will make administration significantly easier and more flexible.

So, short answer: yes, you can do this. I wouldn't suggest it though. If you already have vxvm, then the cost has already been incurred and you might as well enjoy the additional flexibility. You definitely don't want to do this if vxvm is already managing any of your data disks.

Additionally, I'd be paranoid enough about vxvm managing the boot disks to migrate off of that sometime soon.

Doug O'Leary

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Senior UNIX Admin
O'Leary Computers Inc
linkedin: http://www.linkedin.com/dkoleary
Resume: http://www.olearycomputers.com/resume.html
Doug O'Leary
Honored Contributor

Re: Can i use LVM for SAN disks and Veritas for root disks

Allow me to rephrase:

>>That being said, it costs more - a lot more. I have supported any number of configurations with and without vxvm on the data disks for the better part of 6 years now. I can think of only a very few occasions (like maybe 6) where that flexibility made my life easier or would have made it easier had it been available.

I've actually been supporting HP systems for 15 years now; the past 6 have been at one particular client who really likes their vxvm.

Doug

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Senior UNIX Admin
O'Leary Computers Inc
linkedin: http://www.linkedin.com/dkoleary
Resume: http://www.olearycomputers.com/resume.html
Rohak
Advisor

Re: Can i use LVM for SAN disks and Veritas for root disks

As per knowledge , VxVM is more capable than LVM.