Docker installation on RHEL 7.2 and file system requirement

Question

We have old RHEL machine version 7.2

And we prepare to install docker service on this server

The problem is that server's filesystem was created with ftype=0 parametre and docker requires ftype=1

One option of course is to format the disk with mkfs and create new file system with ftype=1

But we want to stay with the original OS and not format the disk

Second option is to perform the step as defined in the post - https://superuser.com/questions/1321926/recreating-an-xfs-file-system-with-ftype-1/1321963#1321963

But this steps are risky and required server to be down

We are searching for third alternative in order to implement the docker installation on rhel version 7.2 in spite ftype=0

Interesting direction could be for example by adding a new disk to the server and create XFS file system, with ftype=1 , but we are not sure how to defined the docker installation on the additional disk (because this disk is actually without OS).

We will happy to get any other ideas out of the box.

It's even more risky to run your server with software that is missing years of security fixes. Do not run RHEL without a subscription (use CentOS instead). You might not even be able to install Docker if you haven't got a RHEL subscription. — Michael Hampton, Aug 12 '20 at 19:11
you are right , but because some sensitive issues ( that are not technical issues ) we cant upgrade the rhel version to higher version , — King David, Aug 12 '20 at 20:36

score 2 · Answer 1 · answered Aug 12 '20 at 09:23

2

It should be possible to add an additional disk formatted with the correct -n ftype=1 flag.

Mount the disk somewhere and point Docker to that location by setting:

{ 
   "graph": "/path/to/your/docker" 
}

in /etc/docker/daemon.json

The fstype flag should be relevant only for the overlay filesystem so it shouldn't matter that the docker binary is stored on a filesystem formatted without that flag.

answered Aug 12 '20 at 09:23

Henrik Pingel

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did you try it? and this is something that was done ? – King David Aug 12 '20 at 09:27
in your example what is the meaning of - "graph"" ? , that should be in /etc/docker/daemon.json – King David Aug 12 '20 at 09:57
No, I didn't test that. graph defines the path where Docker will store the overlay fs – Henrik Pingel Aug 12 '20 at 10:53
do you have some documentation about this approach? – King David Aug 12 '20 at 11:01
3

@KingDavid You can create the new XFS filesystem and mount it at `/var/lib/docker`. Then you do not even need to make any change to the daemon.json file. – Michael Hampton Aug 12 '20 at 13:57
do you mean the new disk ( with ftype=1 ) will mount to /var/lib/docker ?? and thats it? – King David Aug 12 '20 at 18:03
@Michael Hampton better if you post your answer so all users can see and give you up vote , I think your solution is very simple and brilliant – King David Aug 12 '20 at 18:06

score 1 · Accepted Answer · answered Aug 12 '20 at 18:49

1

You can just create a new XFS filesystem on your new disk and mount it at /var/lib/docker. Then you do not need to make any changes to the Docker configuration, as that is the default directory for Docker volumes, images, containers, etc.

answered Aug 12 '20 at 18:49

Michael Hampton

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Docker installation on RHEL 7.2 and file system requirement

2 Answers2