If your existing LUN is a metavolume, it can be done .. if it's a single big volume, no.

The metavolume will remain concat/striped .. it will not change while being expanded.
Can't give feedback on performances .. Never did on a heavy utilized volume. Better to have little I/O IMHO. However YMMV. Maybe someone else may shade some light on performances.

Is there impact on performance?
will metavolume be changed from stripe to concatenated?

I did a test on a heavy loaded machine and the outcome was fabulous:

The windows volume to be expanded was a 4 part meta of 34GB in total and I added 1 symdev. The meta was RAID5 to begin with. The BCV I used (of course) was RAID1 and identically set up (also a 4 member meta with each member identical in size). However: the meta was on 10k disks and the BCV was on 15k disks.

During the expansion we monitored the performance and we noticed an increase in performance during the expansion ! This is of course because the BCV takes over all I/O load during the expansion. After the expansion was done, performance dropped back to normal and for some unknown reason during this "migration" performance was a lower than before, because of the copy back to the 10k disks and since the meta was heavily loaded the migration took some extra I/O's, dropping performance significantly. After is was done, perf was back to normal.

Conclusion: it can be done online, even in heavy I/O environments.

Thx for shading your lights .. Did you pick them from your garden ??

No.... in this kind of weather (lots of rain) I'm working in my basement this time

Hi,

I want to expand a lun (now the lun is not meta) online which is attached to the wintel server, could you please share the steps on how to do that?

Environment:

Windows 2003 STD SP2

Frame - DMX 3

Microcode - 5771.111

Symcli - V6.4.0.4

Thanks

Martin