Newbie to LVM

Hi,

LVM seems to be a good choice for split a linux box hdd. I would like to use this for a database/file server (samba), running under SuSE Linux 8.0 PRO.
I have 2 disks of 73 Go, in RAID 1.

Here is the LVM partition I've created :

linux:/ # lvscan

lvscan -- ACTIVE            "/dev/vg/mysql" [10 GB]
lvscan -- ACTIVE            "/dev/vg/index" [4 GB]
lvscan -- ACTIVE            "/dev/vg/data" [15 GB]
lvscan -- ACTIVE            "/dev/vg/share" [29.35 GB]

lvscan -- 4 logical volumes with 58.35 GB total in 1 volume group lvscan -- 4 active logical volumes

LV are mounted with ReiserFS :

/dev/vg/mysql --> /mysql
/dev/vg/index --> /index
/dev/vg/data --> /data
/dev/vg/share --> /share

All of the LV are shared with samba.

I have some questions :

1. I can write 4.3 GB of data for my XP station to the /index share. The LV is 4 GB ?????

2. What is exactly the extent value ? (default 4MB).

3. What is the best value of this parameter for database ? and a file server ?

Thanks in advance for your response.

--
Sinc�rement,

Jean Marie Ari�s