need to use a vdisk on 2 hp-ux servers same time without service guard?

[Zulfiqar Hanif]

Hello,
we have 2 rx3600 servers installed hp-ux 11.23 and EVA 3000.

i create a volume for 500GB and i want to use for oracle archive logs.
oracle 10g installed with ASM option.

can i use this 500GB volume without service guard as well as oracle ASM?

can i mount the volume on both server at a time?

[Steven E. Protter]

Shalom,

You can create a volume group and mount it in shared mode.

Without benefit of serviceguard or some product to properly share the disk however, you may find the life expectancy of this mount point is measured in seconds.

SEP

[Johnson Punniyalingam]

Yes, you can

#vgchange -c y -S y /dev/vgname # Make Volume Group share and cluste aware

#vgchange -a s /dev/vgname #Activate volume group in shared mode.

Thanks,
Johnson

[Johnson Punniyalingam]

>>>can i mount the volume on both server at a time? >>>

depends if you already activated VG_ Server1

you need deactivated and activate it VG_Server2


Also please check the below Thread

very usefull tips about the "VG_SHARE"

Thanks,
Johnson

[Johnson Punniyalingam]

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=821953&admit=109447626+1227013415252+28353475

[likid0]

You can use share devices(vgchange -a s) if you are using oracle with ASM or raw devices.

And I would say to be able to use vgchange -a s you need Service guard runing anyway.

You can't have the same fs mounted on both servers at the same time, they would get corrupted in seconds

[Zulfiqar Hanif]

my question is, if i the change the VG in share mode, can i you this shared vg for both servers in read/write mode without service guard?
does it will work or i will have data curroption?

[Johnson Punniyalingam]

Hi Hanif,

>> can i you this shared vg for both servers in read/write mode without service guard?
does it will work or i will have data curroption?<<

how would you like to share ..? VG

my understanding and how i would like to share the VG

my example
Currenlty
ServerA:- holding the the shared "VG'

i want to share to ServerB.?

so in-order to share the VG to serverB

# umount /File_system
# vgchange -a n /dev/vg_name
# vgchange -a s /dev/vgname #Activate volume group in shared mode.

# vgchanage -a y /dev/vg_name
# vgchange -a s /dev/vgname
# mount /File_system

by performing the above example of sharing the VG you will not corrupt the LVOLS of the VG,

if you try to activate the VG on the both you have VG Conflit _and may have corruption ..:)

Hope you understand,

Thanks,
Johnson

[likid0]

To use raw volumes and SLVM,you need SG extension for RAC or use cluster file system.

But there is another option, wich is to use:

Oracle RAC 10G with clusterware only and ASM, this way you don't need SG or SLV, you just give the hole disks to asm so it can manage them.

[Zulfiqar Hanif]

yes we already gave 1TB RAW disk to oracle ASM but we want to keep the archivelogs out of the ASM, thats why i am working on other options.

[Wim Rombauts]

Ever thought about NFS ?

We have our archive logs in a separate disk group within ASM. This way there cannot be any interference with the database datafiles, and they are allways available for both instances. Works fine.

Previously, in Oracle 9, every instance had it's own local filesystem for writing archived redo logs, but I had NFS-crossmounts so that instance 2 could read the logfiles of instance 1. Take care the path for system 1 to access it's own logfiles is exactly the same as the NFS-path used by the remote system to access the logfiles.

[Duncan Edmonstone]

>> yes we already gave 1TB RAW disk to oracle ASM but we want to keep the archivelogs out of the ASM, thats why i am working on other options.

Your options are:

1) Serviceguard with a cluster filesystem
2) Use an NFS mount, understanding it will be a single point of failure (I guess you could multiplex your archive logs from within Oracle both to ASM and to the NFS mount point with guaranteed delivery only to ASM - I think Oracle will support that configuration but you'' need to check the options on the oracle archive log parameters)
3) Just use ASM.

There are no other options. Shared LVM (SLVM) and Cluster Filesystems all require Serviceguard.

What's the problem with leaving archive logs under ASM control?

HTH

Duncan

[Zulfiqar Hanif]

Hi,

i tried these commands on serverA but i am facing the problem.
can you please see the output.


# umount /archlog
#
# vgchange -a n /dev/vgarchlog
vgchange: Volume group "/dev/vgarchlog" has been successfully changed.
#
# vgchange -a s /dev/vgarchlog
vgchange: Activation mode requested for the volume group "/dev/vgarchlog" conflicts with configured mode.

do i need the service guard to use it?

[Steven E. Protter]

Shalom,

I am of the opinion, hearing later data, that you must use service guard to accomplish this share. As noted cluster file system requires service guard as a pre-requisite.

ASM may be an alternative, but complete control of the disk must be given to ASM, and that might have to be done via a whole disk, non-lvm configuration.

SEP

[Duncan Edmonstone]

>> do i need the service guard to use it?

Yes - shared concurrent access to a LV in a VG can only be accomplished with Serviceguard. Even then just cos you can have shared concurrent access to the LV, you still can't just stick a normal filesystem on the LV and expect it to work. For that you need a cluster filesystem.

My points above still hold true - those are your options... I'll ask again - what's wrong with keeping your archive logs in ASM?

HTH

Duncan

[Zulfiqar Hanif]

the problem is, we enabled the archivelogs under ASM, but ASM getting full and database stopped. after that we disable the archivelogs. for taking RMAN Backup we want to start it again.
I have a question, we have 1TB for ASM. if i encrease the size for this vdisk from 1TB to 1.5 or 2TB. is it possible of data curroption? or do i need to do anything on hp-ux side. i means if i extend the size in eva, i can use it in ASM or not without data curroption?