VG Recreation & Backing Up data

[abcd7]

Hi All,

I have an FS, which is using a single LV and spanned across 5 PV's, with 4 MB PE size. Since it touched the PE number limit, I can't extend the FS. I am going to recreate the VG with a larger PE size.

Following are the activities, I am going to do


1) Backup the FS to another FS / tape. This is where I got stuck up. Last time, when I did simillar activity, I used 'cp -Rp *' and copied the entire FS to another FS. This took almost 7 ~ 8 hours, as the data is around
250 GB. Is there a way to optimize the this time ?

I have other tools like, 'dd', 'cpio', 'fbackup' and DP / NB, in mind.

Can 'dd' be used to backup the FS, when it spans across 5 PV's. What about LVM headers ? How can I skip them, while using 'dd' ?

Can 'tar' be used to backup data as huge as 250 GB?

2) vgexport < vg_name>

3) pvcreate -f < All 5 PV's>

4) vgcreate -s

5) lvcreate & newfs

6) Restote the data

Did I miss out anything ? Any scope for optimization?

Many Thanks

Doug

[Torsten. · Accepted solution]

Hi,

for hp-ux 11.31 and 11.23 you can use vgmodify to expand the max_pe value to the max. vgmodify for 11.23 comes per patch (PHCO_35524 + dependencies)

[abcd7]

Hi Torsten,

Many thanks for that.The last time, I checked about that with HP, they told me that it is an unsupported tool. I didn't want to take chance then. Is it an HP supported tool now ?

Doug

[Torsten.]

Please read the patch readme:
http://www8.itrc.hp.com/service/patch/patchDetail.do?patchid=PHCO_35524

"...
- a new command, vgmodify, to handle the physical
volume size changes and modify configuration
parameters of an existing LVM volume group"

[abcd7]

Hi,

Thank you very much. I am using 11.11, so have to stick to that cumbersome procedure.

Any suggestions on that ?

Thanks

Doug

[abcd7]

Hi Again,

Going through the man page for 'vgmodify', I notice that it can not be used to change the PE size. In that case there is no option, but to recreate the VG, irrespctive of the OS version.

Regards

Doug

[Torsten.]

As mentioned before, vgmodify can modify the number limit of PE to the max, but not for 11.11.

Regarding "dd", you can perform this on the LVOL level, instead of the disk level. No idea about the performance.
fbackup would be a good way to go.

[abcd7]

Hi,

I have already reached the PE number limit of 65536. So the only option for me is to change the PE size and I don't think it is possible with 'vgmodify' on any version
HP-UX.

Thanks for LV option for 'dd'. I will try it out.

Regards

Doug

[abcd7]

Hi,

Many thnaks for your help. Closing the thread.

Cheers

Doug