Managing partitions in Oracle Enterprise Linux 7

There a quite a few new changes in OEL 7 (and its twins CentOS7, RHEL7, etc.), one of them is the default filesystem is now xfs instead of ext4. Well, I’d just got used to the latter, and in comes xfs, which you cannot shrink????

I asked and got a nice new VM to install one of our products, but the OEL7 installer, in a wisdom that remains its own, decided to to create one massive /home partition filling up the whole disk along side a normal /boot and / partition.

However we needed the separate /u01, /u02, /u03 and /u04. So, that should be easy, quick bit of resize on the logical volumes, create the new ones and job done. But… the new default file system can not be reduced, only increased, so we’ll have to do it the hard way using ssm which is the new tool for managing volumes in OEL 7. Let’s install that first, it is part of the system-storage-manager package:

And run it, widening your default window:

So that 247Gb /home is not what we need, so here’s the plan

  • move  or backup /home/* into some folder on the / volume
  • drop the /home
  • recreate the new volumes using ssm
  • restore /home/* into new volume of same name

Backup

The -p option will ensure we keep the full folder structure

Drop the /home using ssm

Recreate the volumes

Required mount points

This neat trick allows you to create all four folder in one command

Recreate /home

Here I use the same label ‘home’ instead of calling my volume ‘lvhome’ like the rest of them. Calling my volume ‘lvhome’, it would fail to mount for some reason whether using the historical mount command or the variant using ssm (ssm mount /dev/ol/lvhome /home)

You’ll get the following warning message, you can answer yes to wipe the signature:

 

Create all others

Check the results with ssm

Modify /etc/fstab

Or the mount points won’t survive a reboot, note that we use the /dev/mapper names rather than the volume names mentioned in the ssm list

Restore backup

And reboot afterwards, just to make sure everything is OK

David White

About David White

David White has written 18 post in this blog.

Oracle Technologies Consultant at Easyteam

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