Thank you for this explanation which sounds very clear. One more question please. I do not understand why I can not extend my VG with the second RAID partition: [root@fw root]# pvdisplay /dev/md/8 pvdisplay -- "/dev/md/8" is a new physical volume of 125.38 MB [root@fw root]# vgextend secured /dev/md/8 vgextend -- INFO: maximum logical volume size is 2 Terabyte vgextend -- ERROR: physical volume "/dev/md/8" too small for physical extent siz e of volume group "secured" Thanks in advance. Koch, Steffen (steffen.koch@sphinx-electronics.de) wrote*: > >Hello, > >> [root@fw root]# vgcreate secured /dev/md/7 >> vgcreate -- INFO: using default physical extent size 32 MB >> vgcreate -- INFO: maximum logical volume size is 2 Terabyte >> vgcreate -- doing automatic backup of volume group "secured" >> vgcreate -- volume group "secured" successfully created and activated >As it is stated here an extent is 32 MB, and one extent is always lost at >the beginning of the md (partition, disk, etc.) for metadata information. >This should leave you with 125 MB - 32 MB = 93 MB. >LVM volumes have to be a multiple of the extent size. So 32MB, 64 MB, 96 MB. >As you can see your remaining space is 3 MB too little for a 3 extent >volume, leaving you with a 2 extent volume with 2 * 32 MB = 64 MB > >> The size of the partition get shrink by half: >> >> [root@fw root]# pvscan >> pvscan -- reading all physical volumes (this may take a while...) >> pvscan -- ACTIVE PV "/dev/md/7" >> of VG "secured" >> [64 MB / 64 MB free] >> pvscan -- inactive PV "/dev/md/8" >> is in no VG >> [125.38 MB] >> pvscan -- ACTIVE PV >> "/dev/ide/host0/bus1/target0/lun0/part13" of VG "lvm1" >> [17 GB / 16.97 GB fr >> pvscan -- total: 3 [17.28 GB] / in use: 2 [17.16 GB] / in no >> VG: 1 [125.38 MB] >> >> Is this a known/solved problem? >> Did I made a mistake? >> >> Thanks in advance for your help. >> Regards. > >Hope the explanation helped. > >_______________________________________________ >linux-lvm mailing list >linux-lvm@sistina.com >http://lists.sistina.com/mailman/listinfo/linux-lvm >read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > > -- R.Y. Lorin mailto:ryl@free.fr http://les-lorin.webhop.net/ _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
