linking disks between machines.

RalphCC · #1 26th October 2009, 02:15 PM

I am setting up my first disk share between linux machines using just mount to test ( as with mounting win disks) and it doesn't mount. I get messages like "special device - does not exist"
Should I be doing fstab entries from the start or what should I do?. One machine is F11 the other f10 if that makes a difference. I can link one linux to windows on the other machine.
Is this the right forum?
Thanks, Ralph.

zak_neutron · #2 26th October 2009, 04:41 PM

What command are you issuing for the mount?

RalphCC · #3 27th October 2009, 12:40 AM

I've tried all sorts of variations on :
mount otherip:/dev/sda5 /here
I've tried by machine name and by address.
Does it need matching users on each machine - but commands are done as root?.
Ralph

barry905 · #4 27th October 2009, 02:23 AM

If you want to share a disk (or a directory) with another computer you can use either NFS or samba. NFS is really designed for file sharing between Linux (and unix) based PCs, while samba is used to share files between Windows and Linux.

To set up NFS you need to tell the host PC which filesystem to export, and then start the NFS daemon. With samba, you need to configure the samba server and as a part of that you will define the directory tp be shared.

Good luck!

RalphCC · #5 27th October 2009, 05:12 PM

I hadn't found that because it is in a different chapter of the sysadmin book.
I have put root in the export file and will try it out.
Is export a tab separated file because I have put the bg subcommand in?.
Do I refer to the export by the /dev/sd.. construct on the remote machine still?.
Thanks for your help.
Ralph.

barry905 · #6 28th October 2009, 04:41 AM

As an example, here is the /etc/exports file on my server:

/data/downloads *(rw,sync,nohide)
/data/mp3 *(rw,sync)
/data/stuff *(rw,sync)
/more_data/backups *(rw,sync,nohide,no_root_squash)
/misc/exports *(rw,sync)

I can't quite remember the exact syntax, but I believe that each line represents the filesystem to be exported, which machines can access it (it this case all of them, hence *) and any mount conditions (again, in this case read/write). The elements of each line are space and/or tab separated. You can get a full description from the man page (man exports).

To mount the filesystem from the other end, you simply mount it using something like:

mount test.example.com:/misc/export /misc/local

or by adding this to the fstab file:

test.example.com:/misc/export /misc/local nfs rsize=8192,wsize=8192,timeo=14,intr

in both cases this mounts the filesystem /misc/export from the server test.example.com on /misc/local

Hope that helps; if not please ask to more info....

trigpoint · #7 29th October 2009, 08:30 PM

The exports file on my server box includes network ip ranges that are allowed to access the shares, although I have masked them to allow any pc on my network to access them.

Code:

/mydata/data/        192.168.1.0/255.255.255.0(rw)
/home/myhome      192.168.1.0/255.255.255.0(rw)

.

Then to mount them

Code:

mount 192.168.1.10:/mydata/data /mnt/data/
mount 192.168.1.10:/home/myhome/mnt/data/

If you want to share with a windows machine, then install system-config-samba, it makes samba a doddle to configure.

RalphCC · #8 10th November 2009, 08:11 PM

I notice you are both using two levels of directory:
mount ip:/a/b /c/d (ip=an address I can ping)

I am trying :
mount ip:/a /b
does this matter

I get ' mount.nfs: mount(2): Input/output error '
Does this mean the daemons are not started, I can't see anything with ps .
Thanks for any help,
Ralph.

CiaW · #9 10th November 2009, 11:55 PM

I spent hours and hours figuring out and getting NFS to work, between my Fedora7 laptop and my CentOS and now F12 machines. 1st thing: the directory you want to mount to has to already exist. I was used to my usb drive being mounted in /media/bigdrive without the /bigdrive directory existing before it was auto-mounted when I turned it on. So if you're mounting to /b/mystuff then make sure mystuff is a directory in /b.

2nd, unless you get the ports assigned that various NFS services want to use, it'll assign them differently sometimes. So you have to edit /etc/sysconfig/nfs Here are some good articles that explain various aspects of it:
http://kbase.redhat.com/faq/docs/DOC-3259

http://nfs.sourceforge.net/nfs-howto/ar01s07.html

3rd, you have to open the ports you configured above, in the firewall. If you select the service NFS in the firewall setting it'll just open port 2049 (I think that's the one?), and I'd already opened all of the other ones from /etc/sysconfig/nfs and it still wasn't working until I also added port 111 (portmapper -- that one seems to be standard so you don't have to define it). I think that made the difference, though I'm not positive. I have tons of notes I kept, but I didn't note every little thing I did, but I got it to work.

To see what ports are assigned to various parts of the service use the 'rpcinfo -p' command. You'll want them to match between machines.

Lastly, in case you're going to be going to Fedora12, I filed a bugzilla that will hopefully be fixed soon, where the system-config-nfs tool adds an http:/ in front of the host IP -- I had to manually edit the /etc/exports file to get it to mount. There was another rpc.statd bug filed too, against the livecd. I found a fix for that on the bugzilla page.

Hope that helps.