How to share an NFS mount (exported to Unix) to a windows server.

Question

Hi All,

We have a file system exported to a unix server, (mounted on Datamover 4). But its not mounted on a VDM inorder to share it to a windows server.

Could some help me in explaining the correct procedure to share it to a windows server.

Please let me know if you have any questions.

Thank you.

nandas · Accepted Answer

The steps in point 2, 3 and 4 are not accurate - you can not create NFS export using the server name as the VDM - it has to be on a physical server name i.e. server_2 inplace of vdm. And the path will not be /summit - but will be through the vdm name. You also need to create the new mountpoint on the VDM before you can mount the FS on the VDM. Also on step 1 use the -persistent option for unmounting the file system. I am adding steps to delete any existing export on this file system and the existing mountpoint as well. With server_export command you need to use -P (upper case P for Protocol).

So the revised steps will be -

1) Delete any NFS export on the file system /summit

$ server_export server_4 -P nfs -unexport -perm /summit

2) Unmount the file system from server_4

$ server_umount server_4 -perm summit

3) Delete the existing mount point on server_4 for the file system (which will be mounted on a new path so this is a cleaning process to delete unused mountpoint)

$ server_mountpoint server_4 -delete /summit

4) Create a new Mount Point for the file system to be mounted on VDM (this was not needed had the FS was created and mounted through GUI) -

$ server_mountpoint -create /summit

5) Mount the file system back on to the VDM

$ server_mount ¿o rw summit /summit

6) Find the actual path of this file system mounted on VDM - this will also list that the file system is mounted on the VDM

$ server_mount server_4

-- note the path where summit is mounted - it must be /root_vdm_x/summit - where x is the number for the VDM.

7) Create a new NFS Export for the file system :

$ server_export server_4 -P nfs /root_vdm_x/summit -option rw=Client_IP:client_IP root=client_IP:client_IP access=client_IP:client_IP

Please note that the client IP Addresses needs to be mentioned in the command as option

(or)

- Using Celerra Manager ¿ New NFS exports ¿ Select the data mover as sevrer_4 (you don't have any option to choose VDM for NFS export) - Enter the path ¿/root_vdm_x/summit¿ , ignore the drop-down box for choosing file system ¿ Enter IP addresses of unix server in appropriate fields.

8) NFS mount the file system back on server using the new path name ¿

¿datamover_name_or_IP:/root_vdm_x/summit¿ using one of the interface on the server_4 on the Celerra.

Hope this helps - please feel free to revert back, if there is any issue.
Thanks,
Sandip

nandas · Answer

NFS export does not work with VDM. In other words, if can not have a file system NFS exported through Celerra Manager when the file system is mounted on a VDM.

However, if you need a file system to be used by both CIFS and Windows - you can use CLI to create the NFS export and specify the entire mount path for the file system including the vdm root file system in the path.

But, there are many other considerations for Multi-protocol environment like Accesspolicy, User mapping etc. Please refer to the documentation or consult your EMC NAS person for better understanding of your environment and proper suggestions.

My 2 cents

Thanks,
Sandip

Rainer_EMC · Answer

A file system that is not mounted on a VDM can only be accessed by a CIFS server on the physical data mover and not from CIFS servers in a VDM

So if you need to make data from that fs available through an existing CIFS server on a VDM the easiest way to do this is to remount the fs onto that VDM and change the NFS export and client mounts.
You might be able to get around changing the NFS client mountpoint change by using NFS alias.

Alternatively you could create a new CIFS server on the physical data mover and share that fs there.
BUT then you dont have the VDM benefits for replication and seggregation - for example the C$ share on that CIFS server gives potentially access to all VDM mounted file systems.

Rainer_EMC · Answer

- For remounting the file system, do we need to unmount from server_4 and again remount it on VDM?

yes

can it be mounted on both server_4 and VDM?)..

no, a file system can only be mounted once (read-write)

- I didn't get the ur point 'changing the NFS export'

If right now your file system is mounted on the physical data mover then your NFS export is like /
When you mount a file system on a VDM its actually mounted on the VDM root so the NFS export becomes something like /root_vdm_ /

-- what does that mean?

that means your NFS clients would have to mount /root_vdm_ / instead of /

You might be able to keep the / export as an alias (search the forum here for NFS alias)
BUT it can get quite confusing if you dont fully understand it so unless changing your NFS client mounts is a big hassle I wouldnt recommend it.

- Can you please send the commands to implement the change.

basically server_umount, server_mount and server_export

I really recommend creating a small test file system to test this before doing it on a production file system.

Keep in mind that when you change the mount your NFS clients will fail and have to remount with the new path

Kushi2 · Answer

Rainer,I understood your thoughts on what can be done to share an NFS mount. I am totally okay in understanding 'creating a new CIFS server and sharing the file system', but i have few questions and concerns on other alternative (remounting the fs on VDM)- For remounting the file system, do we need to unmount from server_4 and again remount it on VDM? ( can it be mounted on both server_4 and VDM?)..- I didn't get the ur point 'changing the NFS export' -- what does that mean?- Can you please send the commands to implement the change.Thanks in advance.

nandas · Answer

Thanks for adding more clarification to my statement Rainer.

Rainer_EMC · Answer

NFS export does not work with VDM. In other words, if can not have a file system NFS exported through
Celerra Manager when the file system is mounted on a VDM.

Unlike CIFS servers the NFS server is global on the physical data mover.

It doesnt really care where on the whole data mover the file system is.

BUT for some reason if you use the Celerra Manager GUI to create an NFS export it will not show you VDM mounted file systems in the list to select from.

If you figure out the real path of the fs using a "server_mount" command you can happily NFS export it from Celerra Manager as well.

That path simply is /root_vdm_ / where number is a unique number auto-assigned by the system when the VDM is created
If you only have ever created one VDM its /root/vdm_1

That number gets incremented every time a new VDM is created, even if old ones are deleted they are still "reserved"
So if you created and deleted 30 VDM it would be /root_vdm_30

However, if you need a file system to be used by both CIFS and Windows - you can use CLI to create the NFS export and specify the entire mount path for the file
system including the vdm root file system in the path.

yes using the full path you can use the server_export command

You can also create the export using the CLI and then later modify it via the GUI

Rainer_EMC · Answer

Hi Sandip,I agree its not really intuitive to just ignore the fs dropdown box.I will attach some screenshots to hopefully make it clearer.As you found out you will only get the Path input box if you have at least one file system mounted on the physical data moverRainer

Kushi2 · Answer

Thanks a lot for a clear explanation.We have our business owner's approval to unmount the NFS client. So now i can unmount the fs from server_4 and mount it back to a VDM and then export it. If i understand it correct, steps i would follow are:File system - summit1) Unmount the file system from server_4 - server_umount server_4 summit /summit2) Mount the file system back on to the VDM - server_mount ¿o rw summit /summit 3) Export it to the unix server: - server_export -p nfs -o rw /summit (or) - Using Celerra Manager ¿ New NFS exports ¿ Enter the path ¿/root_vdm_z/summit¿ ¿ Enter IP addresses of unix server in appropriate fields. 4) NFS mount the file system back on server using the new path name ¿ ¿/root_vdm_z/summit¿ using one of the interface on Celerra. 5) Share the same file system using the CIFS server ¿abc¿ configured on vdm

Rainer_EMC · Answer

yes, that's itof course all the server_* commands you can also do with the GUII would also recommend to read up on access policies since it looks like you want to exchange data between NFS and CIFS clients

Rainer_EMC · Answer

Could you please take a minute time to open a Product Enhancement Request (PER) to include that functionality directly into Celerra Manager ?

Maybe if enough customers ask for it, we can get it changed.

Just go to Powerlink Home > Support > Request Support > Request a Product Enhancement
click Get Started.
click Accept
select Celerra General as Product
...

then describe that you want to be able to create an NFS export of a VDM mounted file system through Celerra Manager
that currently the file system drop-down box for the NFS export doesnt show any VDM mounted file systems to select

If you want to can attach my attachment to describe the workaround

thanks
Rainer

nandas · Answer

Great to know that everything worked properly - thanks for the feedback - our absolute pleasure to be of any help.

In fact I also get benefited with these discussions - the one which Rainer mentioned (creating NFS export for a FS mounted on VDM using Celerra Manager) was new to me

- Thanks Rainer.
So participating in the forums help me as well

Catch you later -
Regards,
Sandip

Kushi2 · Answer

Thank you Sandip/Rainer. I really appreciate all your help in clarifying all my doubts here.

The process sandip posted was of great help to me. Thanks once again.

I'm actually new to NAS and finding hard time in learning things. Mainly Access policies, getting confused my self while reading too much stuff on powerlink.

Hope I'll get through all difficulties in understanding the topics. With your help ofcourse.

You guys are great.

Peter_EMC · Answer

MREW6oy2Xk1251284911525 wrote:I'm still confused.... Just create a share for your windows users of the filesystem fs-nfs-lifescicam.

Blondini56 · Answer

I'm still confused.

We have a filesystem that is exported as an NFS share that we would also like to be able to access from some windows systems, can someone please explain how we do this with the existing filesystem?

The filesystem is fs-nfs-lifescicam which is on server_3 (on our NS480), we also have a cifs server running on server_3

Thanks Nick

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How to share an NFS mount (exported to Unix) to a windows server.

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