VxVM with DMP

[John Tolnay]

I am trying VxVM 3.5 for the first time. I seem to be missing some configuration setting, or, something. I'm have problems with DMP working the way I think it should.

- Using 11i v2 (B.11.23) and a demo license for VxVM.
- Two fibre channel path to storage disk, each path accesses all the same disk
- Created sub disks for each "real" disk.
- Created plexes with three sub disks from three different disks.
- Created one volumes with one plex each.
- Created file systems and mounted them as type vxfs.
- Started running I/O, used IOSTAT and saw both paths were being used.
- Dropped one fibre connection, I/O continued, IOSTAT showed only path active.
- Reconnected the fibre, in 5 minutes (the default setting for the daemon) both paths active again.
All this is as expected.

When I drop one fibre connection, let second path pick up all activity.
I reconnect the first path and drop the second path within 5 seconds.
I/O fails, no devices found.

I expected that I/O would be blocked for at least a little while, not fail immediately.
There must be a system related setting, or VxVM config I'm missing.

Thanks.

[G. Vrijhoeven]

Hi John,

You could check the the Administering DMP Using vxdmpadm section:

# vxdmpadm start restore interval=400

The default interval is 300 seconds. Decreasing this interval can adversely affect system performance


http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/5971-4765/5971-4765_top.html&con=/hpux/onlinedocs/5971-4765/00/01/147-con.html&toc=/hpux/onlinedocs/5971-4765/00/01/147-toc.html&searchterms=timeout&queryid=20040407-131728

HTH,

Gideon

[John Tolnay]

I did see that, thanks. The issue is it would have to be set to around 4 seconds, which dosen't seem right.

I was thinking that there was a setting for the fibre channel adapter. I still can use some help on this.