topic LV syncing in Operating System - HP-UX

LV syncing

Need to migrate XP Back — Thu, 29 Jul 2010 09:07:52 GMT

Hi,

We are planning to perform a major HW change in our netapp so I want to know impact of file system which mounted on the netapps

I will explain the current setup and queries below

Current setup

Netappa1 and a2 are clustered and netapp b1 and b2 are clustered

In the server we are using LV level mirroring (os is HP-UX 11.23 ) also using MC Service guard for SAP for the clustering part

Each cluster netapp will assign each luns in single VG ( each LUN is having 8 paths 4 primary and 4 secondary ) and mirroring is happening on LV level

Also we are using PVG , one netapp cluster will on PVG and another is other PVG

Query

If we down the one netapp clusters for 6 hours (in Vg secondary cluster netapps Lun will be visible ) and once the HW change complete
If we need to perform a manual syncing for Luns which coming from same netapp ,if the data writing is happening at the down time period how ther data will be syncyed on the other netapp Luns
Also if syncing is required if how I can perform this , also if required to remirror the LV ?

We are using PVLINKS only no multipathing software is using

If anybody can update me the above queries it will highly appreciated

Re: LV syncing

Torsten. — Thu, 29 Jul 2010 09:41:26 GMT

Normally it will sync automatically, but if you have a planned downtime, you should use

# pvchange -a N ...

to diable LVM access to the downed LUNs, do the work, and finally activate it either by pvchange -a y ... or just vgchange -a e ...

Doing this you make the life easier for LVM to handle the "failed" disks.

Re: LV syncing

Kapil Jha — Fri, 30 Jul 2010 02:17:36 GMT

so what I have understood is like you want to remove some LUN from a mirrored LV, change the hardware and sync the data.

So you don have to worry much about it, just deactivate the PV as suggested above do the h/w and reenable.LVM would take care of syncing you don have to worry about it.

BR,
Kapil+