topic Re: Accessing a lun with NFS in Network and Storage Protocols

Accessing a lun with NFS

onforceinc — Thu, 05 Jun 2025 07:28:49 GMT

I used the following command on filer as specified in Netapp's docs:

lun share /vol/vol1/qtree1/lun2 all

what is the next thing to do on the host (linux) to mount it as NFS? and be able to access it and see the data

Thank you

Re: Accessing a lun with NFS

adamfox — Mon, 27 Apr 2009 22:24:24 GMT

You will see the LUN via NFS, but not the data inside the LUN. This is most useful for things like backing up a LUN via NFS.

Re: Accessing a lun with NFS

scottgelb — Tue, 28 Apr 2009 01:12:50 GMT

I saw a post about someone who used "losetup" on Linux and "lofiadm" on Solaris to do a loopback mount... mount a volume with a shared lun over nfs. Then use the loopback mount to the lun in the nfs mount. It is pretty slick, but I'd wonder why you wouldn't use iSCSI instead to mount the lun directly to get block i/o to the device. Or like Adam mentioned, a way to backup a lun over nfs by mounting the volume.

Re: Accessing a lun with NFS

onforceinc — Tue, 28 Apr 2009 03:07:40 GMT

Any example on how to use losetup on linux?, the lun is using FCP not iSCSI.

I wanna be to see the data before recovering.

Re: Accessing a lun with NFS

wmccormick — Fri, 07 Jan 2011 16:38:55 GMT

Has anyone successfully done this?

I'm going to be giving it a go in the next few days. I'll let you know what steps I used and whether or not it works.

Re: Accessing a lun with NFS

wmccormick — Fri, 07 Jan 2011 18:19:11 GMT

LOL. Seek and ye shall find.

It's explained quite well right here:

http://en.wikipedia.org/wiki/Loop_device

Re: Accessing a lun with NFS

Darkstar — Mon, 10 Jan 2011 14:21:27 GMT

You can still export the LUN via iSCSI even if it's already mapped to an FCP initiator.

It's not an "either ... or" relationship, both iSCSI and FCP can be active on the same LUN at the same time.

Just create an iSCSI igroup and map the LUN to it. Make sure you only mount it read-only though!

-Michael

Re: Accessing a lun with NFS

zawik — Wed, 18 May 2011 09:09:54 GMT

Hi,

A little old topic but i was just wondering what the command lun share <path> actually does? You can see the LUN as a file wether you share it or not, so what is that for ; regarding that you cannot get access to the lun over NAS and :

Note
A LUN cannot be extended or truncated using NFS or CIFS protocols.

If you want to write to a LUN over NAS protocols, you must take the LUN offline or unmap it to prevent overwriting data in the LUN using the SAN protocol. To make a LUN accessible to a host using a NAS protocol, complete the following steps.

Step	Action
1	Determine whether you want to read, write, or do both to the LUN over the NAS protocol and take the appropriate action: If you want read access, the LUN can remain online. If you want write access, ensure that the LUN is offline or unmapped.
2	Enter the following command: *`lun share` lun-path* `{none\|read\|write\|all}`** Example lun share /vol/vol1/qtree1/lun2 read Result The LUN is now readable over NAS.

Step

Action

Determine whether you want to read, write, or do both to the LUN over the NAS protocol and take the appropriate action:

If you want read access, the LUN can remain online.
If you want write access, ensure that the LUN is offline or unmapped.

Enter the following command:

lun share lun-path {none|read|write|all}

Example

lun share /vol/vol1/qtree1/lun2 read

Result

The LUN is now readable over NAS.

Re: Accessing a lun with NFS

freeb — Wed, 05 Oct 2011 11:32:54 GMT

if i would copy the lun with the share options read with cifs or nfs, how it is possible to restore it.

if i copy it back to another volume, the lun doesn't appear with lun show etc.

thanks

Re: Accessing a lun with NFS

freeb — Wed, 05 Oct 2011 12:10:22 GMT

i could answer myself:

lun create -f <file_path> -t <ostype> [ -o noreserve ] [ -e space_alloc ] <lun_path>