issue of Lvmerge

[SR_2006]

Dear all,
We are spliting mirrored LV & after that again we are merging it.Normal time taken for lvmerge is 30 minutes but sometimes it is taking more than 01:30 & sometimes 30 minutes only!!!!!!!!
What could be the reason.we had also changed the schedule time of Lvmerge but still same problem.
pl. guide .
thanks.

[Jannik]

the time depend on the load of the server and the SAN cabinet. It has to rewrite from disk to disk overwriting data.

lvmerge(1)
Data previously contained in the dest_lv_path is resynchronized using
the data in the src_lv_path. All new data on the dest_lv_path is destroyed.

In other words you will have stale partitions with lvdisplay -v lvol then you can count each minute and compare with data from say glance.

while true
do
print -n `date`" : ";lvdisplay -v /dev/vg00/lvol8 | grep stale | wc -l
sleep 60
done

This enables you to see when it is slow and when it is fast.

[SR_2006]

thanks for ur information.
We confirmed that there is no other process going on the server.
Also tried to run it at different time rather than schedule time but same problem exists.
Any clue please.

[Jannik]

Do you get any information from:
dmesg
or
syslog.log

If you are using some kind of backup system what does it tell you?

[SR_2006]

Thanks Jannik,
Already we checked syslog there is no error.Also Hp is telling that there is no issue of VA7410 it is OK.
Other programs are working fine on server.

[SR_2006]

Thanks all