lvm

[christian_derek]

Hi,

What will be the best choice for manageability and high availability. We have purchase an rx7640 and eva. The hpux system will have few customers that have each one few env into a single instance of the o/s (prod, preprod and test). There is 2 area I want to protect, client db and the clients apps.

option1
Should I build vgdata and vgapps with a logical volume for each of my client inside the vg.

eg
/dev/vgdata/lvol1_client1_prod
/dev/vgdata/lvol2_client1_test
/dev/vgdata/lvol3_client2_prod

with mount point
/data/client1/prod
/data/client1/test
/data/client2/prod

or

option2
should I build a vg per client env

eg
/dev/vg_client1_prod/lvoldata
/dev/vg_client1_prod/lvolapps
/dev/vg_client1_test/lvoldata
/dev/vg_client2_prod/lvoldata

with mount point
/client1/prod/data
/client1/prod/apps
/client1/test/data
/client2/prod/data

pros and cons will be appreciated with any recommendations.

Thanks,

[Torsten.]

If possible, I would separate each client and prod and test to different servers. If not possible, consider to go with option 2, because if 1 VG is down for any reason, all your client applications will be down too.

[Liviu I.]

Hi Christian,

I would enforce a clear separation between prod and test (as you did in both) but also between the data and apps (as you did in the latter). The advantages I see: you may have different backup strategies for data and apps (apps will change not so frequently); apps have I/O files, log files , which should comply to different operations policies than the data.
Also, as you designed the latter, this reflects on the EVA in different virtual disks (which may have different redundancy techniques; thus optimizing for space and performance). Maybe you will implement disaster recovery for this , and adopt Continuous Access : each DR group I think it's best to be separated between data and apps. Also any fine tuning performance improvement techniques on the storage are dependent on the flexibility your design allows (maybe you want one controller to handle data , and the other apps issues).

L.

[Prashanth Waugh]

Hi Lvm,

I am agree with torsten.

use the different vg for prod app test, client wise. So it will avoid the conflict and troubleshooting will be easy also business continuity will be achieve.

Regards
prashant

[christian_derek]

ok, if I go with option 2.

On the eva side I will need to build vdisk for each lun that I will present to my unix system.

I will have a lot of vg:
/dev/vg_client1_prod
/dev/vg_client1_test
/dev/vg_client2_prod
...
/dev/vg_client10_test

Do I absolutely need to build a lun for each vg or I can share lun? The reason I'm asking if for provisioning, I think it will more difficult to plan disk spaces!!!

Thanks,

[Torsten.]

Share a LUN between what?

If you want to create 2 different filesystems in a single vdisk (LUN) - no, don't try this.

What is your OS? If 11.31 consider to use LVM 2.1 and you can easily extend the virtual disks sizes if needed.

[christian_derek]

yes, my o/s is 11iv3.

so, if I build vdisk client1_prod of 50gb, build a vg_client1_prod with few lv that will share the 50gb.

What you are telling me is that I will be able to increase the size of the vdisk and automatically without shutdown anything, I will get the increase disk space at the hpux level, but only if I use lvm 2.1?

what is the impact of doing so?

thanks,

[christian_derek]

Hi,

why you are saying to use LVM 2.1? it look like DLE (dynamic lun expansion) will work for me with version 1. Is there other features that will be helpfull in 2.1?

Thanks,

[Steven E. Protter]

Shalom,

Newer versions of LVM can expand logical volumes without intervention.

That feature actually frightens me a bit, because you are never sure if the amount is going to be right and the disk configuration will be correct.

However in this case you are looking at presenting the data in a LUN, and you're concerns are minimal.

Here is a document to explain the features.
http://docs.hp.com/en/5992-4589/ch01s04.html

SEP

[Alzhy]

Are you building this server as a simply a file server with no aplications/databases on it?

Why don't you just employ vPars and segregate the environments if you have the $$$?

Also if you're on 11.31, you may want to use VxVM base since 11.31 already offers you path protection and load balancing to your EVA.

[christian_derek]

the only reason I am not using vpar or vm is because of third party cost,

the server will host db and application and it will not be a file server.

Thanks,