In-Place upgrade from RHEL 6 to RHEL 7

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We are planning to upgrade a system from RHEL 6 to RHEL 7 using in-place upgrade method. We would like to know if there is a recommended space must be available on the partitions/mounts in order to support in-place upgrade.

The partition and Logical volumes on our systems as follows.

/dev/mapper/rootvg-root 20G 12G 6.9G 64% /
/dev/sda1 283M 141M 128M 53% /boot
/dev/mapper/rootvg-var 7.8G 1.4G 6.0G 19% /var

The root disk size is 40GB , 8GB space has been allocated to swap LV and 3GB free space is available in root VG.

Responses

Hi Arumugavel,

Better don't try to upgrade from RHEL 6 to RHEL 7 - even tough it may be possible (somehow), it is not recommended.
Too many things can break. Please perform a fresh, clean installation. Backup your data and restore it back afterwards. :)

Regards,
Christian

Hi Christian,

Thanks for your response.

This server is running Oracle database and I have already done this upgrade on other two servers (running oracle), they are running fine. Yes, there are many libraries and other compatible issues during the pre-upgrade assessment, but luckily that didn't affect the database post upgrade.

Regards, Arumugavel P

Hi Arumugavel,

In the end it's up to you to decide, of course - but you should consider that these "many libraries and other compatible issues" (under the hood) might hit you badly at some later point of time. :)

Regards,
Christian

Hi Christian,

You really scare me. :)

The servers are running for almost a year now after upgrade. If it is going to hit me later than years, then it is obviously not going to be a upgrade bug.

My original question is still unanswered :(

Regards, Arumugavel P

Hi Arumugavel,

No intention to "scare you" - I only tell the truth. But as I said : it's up to you. The answer to your
question is quite easy, it depends on what you have installed. If the storage space was sufficient until now, it should be sufficient in the future too, from the details you have provided at least. :)

Well, and for how much additional space is temporarily needed during the installation / upgrade
process ... please refer to the release notes and follow the instructions of the installation guide.

Regards,
Christian

The Oracle database seems to be fairly tolerant of a change of operating system provided the version you have installed supports the OS version you are going to. As to the space required the real question is how much of the space used in your / and /var is operating system software as that is what will determine how much space you will need though hopefully the upgrade tool will stop you upgrading if there isn't enough space. However the main thing for any upgrade is to have a good plan to get back to where you started from if the upgrade deosn't work out as planned.

Hi Michael,

I completely agree with you ... having a current system backup image handy is absolutely mandatory ! :)

Regards,
Christian

Thanks Everyone. We have done the upgrade and seems everything is working fine. The system is a VMware guest and we had taken a snapshot before upgrade.

You're welcome, Arumugavel ! Taking a snapshot was a good idea. Glad to read that everything works fine. :)

Regards,
Christian