On Tue, Jun 25, 2013 at 11:45:59PM +0200, Marc Roos wrote: > > We have a reshaped a raid5 array from 11TB to 14TB, on top of this we > have a drbd device that resized to 14994.5 GB, 14994541563904 bytes, > but after the pvresize I have > > > pvdisplay > --- Physical volume --- > PV Name /dev/drbd21 > VG Name VGstorage21 > PV Size 13.64 TB / not usable 948.00 KB > Allocatable yes > PE Size (KByte) 4096 > Total PE 3574977 > Free PE 717377 > Allocated PE 2857600 > > > Is it normal to have this much loss? > > Thanks in advance, > Marc Don't confuse SI units with "binary" units. pvdisplay TB are actually TiB. 1000 != 1024 1000 * 1000 * 1000 * 1000 != 1024 * 1024 * 1024 * 1024 x**y --> x to the power of y 10**12 / 2**40 = 0.91 2**40 / 10**12 = 1.1 14994541563904 / 2 ** 40 13.64 So yes, in the "terra" range, it is normal to have about 10 percent "loss" due to "unit confusion". more recent LVM tools try to make that clear by using TB, GB vs TiB, GiB and so on. you can specify --units in lower case letters for "base 1024", upper case for "base 1000" units. pvdisplay --units t pvdisplay --units T pvdisplay --units g pvdisplay --units G (same goes for all lvm tools) Lars -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT, Austria. _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
