Re: [gentoo-user] unmounting /usr in single user mode

[Allan Gottlieb]

Alex Schuster <wonko@×××××××××.org> writes:

> Allan Gottlieb writes:
>
>> I am unable to umount /usr in single user mode on an old system.
>> I believe the system is baselayout-1 and is amd64.
>> The trouble is open files, at least some of which appear to be related
>> to bash and locale (see the files below).
>>
>> I use grub.  On the kernel line can I specify sh instead of bash?
>> I know sh is linked to bash, but hope that it will not use locale.
>
> Why not use a live-cd?

Good idea.  I certainly have a gentoo installation CD.
I guess I need to ensure lvm is running.  I would try this now except
for your intriguing comment below 

>> I need to umount /usr so that I can resize it (I use lvm and have
>> already extended the logical volume).  Specifically i want to execute
>> umount /usr
>> resize2fs /dev/vg/usr
>> mount /usr
>
> As long as you extend the size, resizing works online, without the need to
> unmount a partition. That's only necessary when reducing the size. Hooray!

This is by far be the easiest soln.  I was misled by lvm howto
(http://www.tldp.org/HOWTO/LVM-HOWTO/extendlv.html), referred to by the
gentoo lvm guide.  The howto states

  ext2/ext3

  Unless you have patched your kernel with the ext2online patch it is
  necessary to unmount the file system before resizing it. (It seems
  that the online resizing patch is rather dangerous, so use at your own
  risk)

   # umount /dev/myvg/homevol/dev/myvg/homevol
   # resize2fs /dev/myvg/homevol
   # mount /dev/myvg/homevol /home

However, this document's latest copyright notice is 2006 and clearly the
kernel has evolved.  Indeed the current man page for resize2fs
states that the file system can indeed be extended while mounted
(providing it is mounted as ext3).

thanks for setting me straight.
allan