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VxDMP on top of RDAC/MPP

guyver-t1
Level 2

Hiya,

I have a setup that I need to 'fix'...

Currently it appears the servers have RDAC/MPP as the primary multipathing , however for what ever reason, it also has Veritas Volume Manager sitting atop of this!

MPP is dealing with the pathing and presenting VxDMP with one 'virtual' path. Below is a vxdisk list example.

Device:    disk_0
devicetag: disk_0
type:      auto
clusterid: x_1
disk:      name=x1-1 id=x2
group:     name=xdg id=x1
info:      format=cdsdisk,privoffset=256,pubslice=3,privslice=3
flags:     online ready private autoconfig shared autoimport imported
pubpaths:  block=/dev/vx/dmp/disk_0s3 char=/dev/vx/rdmp/disk_0s3
guid:      -
udid:      IBM%5FVirtualDisk%5FDISKS%5F600A0B80006E0140000035F24C090009
site:      -
version:   3.1
iosize:    min=512 (bytes) max=2048 (blocks)
public:    slice=3 offset=65792 len=1140661648 disk_offset=0
private:   slice=3 offset=256 len=65536 disk_offset=0
update:    time=1299520130 seqno=0.29
ssb:       actual_seqno=0.0
headers:   0 240
configs:   count=1 len=51360
logs:      count=1 len=4096
Defined regions:
 config   priv 000048-000239[000192]: copy=01 offset=000000 enabled
 config   priv 000256-051423[051168]: copy=01 offset=000192 enabled
 log      priv 051424-055519[004096]: copy=01 offset=000000 enabled
 lockrgn  priv 055520-055663[000144]: part=00 offset=000000
Multipathing information:
numpaths:   1
sdb             state=enabled
 

I going to be removing the MPP layer to allow VxDMP to take over, however my question is how will this effect my VxVM config?

I'm hoping VxVM upon reboot will pickup the new paths etc, but will this effect in any way the DG's that sit on top of this? Note these are shared luns across a cluster. Do I need to worry about the dmppolicy+disk.info files etc ?

I hope the question makes sense!

 

Thanks

1 ACCEPTED SOLUTION

Accepted Solutions

Gaurav_S
Moderator
Moderator
   VIP    Certified

Hello,

can you update on what version of vxvm you are using ?

If its a latest version (5.x), I would say If the DA names (first coulmn of vxdisk_list) stays there as it is, vxvm config would be intact. vxdmp should manage to populate the paths underneath it & vxvm should detect the private regions of the disk.

Regarding disk.info, it would be worth to keep a backup in some other directory unless you get to a working setup.

DMP understands the multiple paths based on serial no. of the Lun, so if two different paths return the same serial number, vxdmp will treat as alternate paths to each other. 5.0MP3 onwards, there is feature of binding disk names with AVID (array volume ID) .. if this feature is used, ofcourse your DA name would be bounded to AVID & since you are not making any changes to AVID, DA names should remain intact which closely tells diskgroups should be fine.

regarding dmppolicy, don't think you need to bother, you can set it according the type of array you are using at later stage.

 

Gaurav

View solution in original post

1 REPLY 1

Gaurav_S
Moderator
Moderator
   VIP    Certified

Hello,

can you update on what version of vxvm you are using ?

If its a latest version (5.x), I would say If the DA names (first coulmn of vxdisk_list) stays there as it is, vxvm config would be intact. vxdmp should manage to populate the paths underneath it & vxvm should detect the private regions of the disk.

Regarding disk.info, it would be worth to keep a backup in some other directory unless you get to a working setup.

DMP understands the multiple paths based on serial no. of the Lun, so if two different paths return the same serial number, vxdmp will treat as alternate paths to each other. 5.0MP3 onwards, there is feature of binding disk names with AVID (array volume ID) .. if this feature is used, ofcourse your DA name would be bounded to AVID & since you are not making any changes to AVID, DA names should remain intact which closely tells diskgroups should be fine.

regarding dmppolicy, don't think you need to bother, you can set it according the type of array you are using at later stage.

 

Gaurav

View solution in original post