Re: Moving LVM volume?
On Thu, 1 Jan 2015 01:54:39 +0000 (UTC)
Frank Miles <fpm@u.washington.edu> wrote:
> I recently added a new hard drive to my home system. I decided to
> use it to create an all-new bootable 'jessie' system. I created a
> partition table that I thought would be flexible:
> /dev/sdb1 / (root) {7G}
> /dev/sdb2 /swap {4GB}
> /dev/sdb3 /oldjunk {1G}
> /dev/sdb4 extended {remainder}
> /dev/sdb5 LVM {one large volume}
>
> Most of the partitions- /usr, /home, /var, ... were in LVM2.
>
> What I've learned since then is that /usr seems to have special
> status, and probably shouldn't be part of LVM as certain tasks
> early in the boot process can't seem to access the interior of
> LVM.
>
> I've moved 'oldjunk' into the LVM, and want to expand this
> partition to become the new /usr. I've shrunk the LVM, but
> the freed space is all at the far end of the LVM. I have
> been unable to move it towards the end of the disk space,
> so I can expand /dev/sdb3. gparted, resize2fs, pvmove,...
> (running from a CDROM-based rescue disk) have all failed.
>
> Is there some method that I've overlooked?
>
Is the system installed and running yet? If so, check the space used by
the main mountpoints. Almost certainly, /usr is the largest of the
system partitions. My workstation /usr is about 8GB, and I don't have
any modern games. Excluding /home, the total is just over 10GB.
Next, there's no problem having the entire system on LVM, including
/boot. I still have a /boot partition, for legacy reasons, but the rest
is in one LVM volume, indeed in a single partition apart from /home. On
a workstation, there's no great advantage to using separate partitions
for anything else.
Next, unless you want to mess with the building of the boot ramdisk,
the issue with /usr is that it must be mounted at the same time as the
root partition gets mounted during boot, so it needs to be physically
stored under /, and any separate /usr partition will still potentially
have problems. At the moment, I'm not aware of any show-stoppers caused
by having a separate /usr, but I've no doubt it will happen in time.
To be honest, unless you already have a significant investment in the
new system, I'd suggest starting again.
--
Joe
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