I have a basic GlusterFS running with 3 GlusterFS machines.
Its set up roughly like
this.
See http://www.whiteboardcoder.com/2023/03/glusterfs-etcfstab-mount-options.html [1] for details on how I set up the mount in
/etc/fstab
So in /etc/fstab I have
the following defined.
|
#defaults = rw, suid, dev, exec, auto, nouser, and async. 192.168.0.200:/volume-one
/volume_one_client glusterfs defaults,_netdev 0 0 192.168.0.200:/volume-two
/volume_two_client glusterfs defaults,_netdev 0 0 |
I have 3 Gluster FS
servers located at
192.168.0.200
192.168.0.201
192.168.0.202
The I mount the drive
via 192.168.0.200
but I could do it on any of the three servers.
OK let me first just
test this out to see what happens.
I have the mount points set up and working and now I am going to shut off
glusterfs on 192.168.0.200.
Check the status
|
> sudo systemctl status
glusterd |
Now stop it.
|
> sudo systemctl stop
glusterd |
And recheck status
|
> sudo systemctl status
glusterd |
OK now after that is off what do I see from my client…
|
> df -h |
I still see the drives let me see if I can read/write still to them
|
> tree
/volume_one_client/ /volume_two_client/ |
OK I can still see everything but can I write a new file…
|
> echo "THIS IS
FILE STUFF" >> /volume_one_client/new_file.txt |
OK now test
|
> tree
/volume_one_client/ /volume_two_client/ |
Yep we are good.
Looks like this is the built in nature. See https://unix.stackexchange.com/questions/213705/glusterfs-how-to-failover-smartly-if-a-mounted-server-is-failed [2]
|
You are initially connecting to one of the nodes that make up
the Gluster volume, but the Gluster Native Client (which is FUSE-based)
receives information about the other nodes from gluster-server-01. Since the
client now knows about the other nodes it can gracefully handle a failover
scenario. |
Nice..
OK I am going to go the full route and shut the machine off.
I am going to reboot my client server that has the mount points
|
> sudo reboot now |
|
> df -h |
Nope it cannot mount it
if 192.168.0.200 is down.
That makes sense… I guess I can update /etc/fstab with 201 and have it work.
So… good news is if there is a server down in the glusterFS we do not lose our
connection. But if we have to restart and the mount server is down we will not
be able to reconnect to it without some changes to the /etc/fstab file.
As a test let me update
/etc/fstab while 192.168.0.200 is still down.
|
> sudo vi /etc/fstab |
|
> sudo mount -a |
References
[1] GlusterFS /etc/fstab mount
options GlusterFS/NFS testing in Ubuntu 22.04
http://www.whiteboardcoder.com/2023/03/glusterfs-etcfstab-mount-options.html
Accessed 03/2023
[2] GlusterFS how to failover
(smartly) if a mounted Server is failed
https://unix.stackexchange.com/questions/213705/glusterfs-how-to-failover-smartly-if-a-mounted-server-is-failed
Accessed 03/2023
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