gconcat - adding additional disks

[Lee Dilkie]

Hi Folks,

I'm going to add a third disk to my gconcat array and I've googled the 
problem and from what I read it can be as simple as:

<current config>
$ mount
/dev/ad0s1a on / (ufs, local)
devfs on /dev (devfs, local)
/dev/ad0s1d on /usr (ufs, local, soft-updates)
/dev/concat/usr2_concat on /usr2 (ufs, local)

$ gconcat list
Geom name: usr2_concat
State: UP
Status: Total=2, Online=2
Type: AUTOMATIC
ID: 3187483959
Providers:
1. Name: concat/usr2_concat
   Mediasize: 200059870208 (186G)
   Sectorsize: 512
   Mode: r1w1e0
Consumers:
1. Name: ad2
   Mediasize: 120034123776 (112G)
   Sectorsize: 512
   Mode: r1w1e1
   Start: 0
   End: 120034123264
2. Name: ad3
   Mediasize: 80025747456 (75G)
   Sectorsize: 512
   Mode: r1w1e1
   Start: 120034123264
   End: 200059870208
</current config>

<proposed procedure>
{add new drive */dev/ad1*, reboot}
*{QUESTION? do I need to fdisk or bsdlabel the new drive?}*
$ umount /usr2
$ gconcat stop usr2_concat
$ gconcat label usr2_concat /dev/ad2 /dev/ad3 /dev/ad1
$ growfs /dev/concat/usr2_concat
$ mount /usr2

</proposed procedure>

Would this work? Do I need to fdisk or bsdlabel the new disk or what?

Any pitfalls to growing my gconcat array this way?

Sorry for the dumb questions, I'd like to get it right.

thanks,

-lee