|
Home > Archive > Unix administration > August 2006 > Read-only NFS filesystem although mounted rw
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
Read-only NFS filesystem although mounted rw
|
|
|
| Hi,
I have a server exporting several NFS shares. All have the same export
rights set. Among them are the shares /home and /pub.
/etc/exports on server:
/pub 192.168.1.1/255.255.255.0(rw,async)
/home 192.168.1.1/255.255.255.0(rw,async)
As you might have guessed, /home holds the home directories of some users
and /pub is just providing some software.
On the server, /home resides on the local hard disk (/dev/sdb), while /pub
resides on an external raid-array (/dev/sdc) which is mounted under /raid.
(kernel module aic7xxx to mount the easyraid system) /etc/fstab (on
server):
/dev/sdb1 /home auto defaults,usrquota 0 0
/dev/sdc1 /raid auto defaults 0 0
On the local client, both shares are mounted in the same way:
/etc/fstab on local pc:
192.168.1.10:/home /home nfs rw 0 0
192.168.1.10:/pub /pub nfs rw 0 0
If I check the way its mounted, with "mount" it shows "rw" for both shares.
Now, here is my problem: When I try to create/alter/delete a directory in
/home on the local pc, everything works, like its supposed to. Meaning,
userX can delete a directory /home/userX which belongs to him or alter its
permissions. When I try to do the same in /pub, its not possible, but
shows the error message "Read-only filesystem". Meaning, userX can not
alter/delete a directory /pub/userX although it belongs to him. It doesnt
matter, if I`m root or regular user.
Server is Red Hat 8 running a 2.4.18-14 kernel with nfs-utils-1.0.1-2.80
What am I missing ?
Thanks in advance,
DD.
| |
|
| I forgot to mention, that I tried searching the web for a solution but I
only found other people haveing the same problem, without any solution.
DD.
| |
|
| I also forgot to list the permissions, the relevant directories have on
the server:
drwxr-xr-x 93 root root 4096 Jun 16 16:55 home
lrwxrwxrwx 1 root root 10 Apr 18 2005 pub -> /raid/pub
drwxr-xr-x 9 root root 4096 May 15 05:42 raid
> I have a server exporting several NFS shares. All have the same export
> rights set. Among them are the shares /home and /pub.
> /etc/exports on server:
> /pub 192.168.1.1/255.255.255.0(rw,async)
> /home 192.168.1.1/255.255.255.0(rw,async)
| |
|
| /raid:
drwxrwxr-x 21 root root 4096 Jul 31 14:48 pub
> I also forgot to list the permissions, the relevant directories have on
> the server:
> drwxr-xr-x 93 root root 4096 Jun 16 16:55 home
> lrwxrwxrwx 1 root root 10 Apr 18 2005 pub -> /raid/pub
> drwxr-xr-x 9 root root 4096 May 15 05:42 raid
| |
| Barry Margolin 2006-08-01, 1:26 pm |
| In article <pan.2006.07.31.12.45.28.894738@rwth-aachen.de>,
DD <dominik.dierkes@rwth-aachen.de> wrote:
> Hi,
>
> I have a server exporting several NFS shares. All have the same export
> rights set. Among them are the shares /home and /pub.
> /etc/exports on server:
> /pub 192.168.1.1/255.255.255.0(rw,async)
> /home 192.168.1.1/255.255.255.0(rw,async)
>
> As you might have guessed, /home holds the home directories of some users
> and /pub is just providing some software.
>
> On the server, /home resides on the local hard disk (/dev/sdb), while /pub
> resides on an external raid-array (/dev/sdc) which is mounted under /raid.
> (kernel module aic7xxx to mount the easyraid system) /etc/fstab (on
> server):
> /dev/sdb1 /home auto defaults,usrquota 0 0
> /dev/sdc1 /raid auto defaults 0 0
>
> On the local client, both shares are mounted in the same way:
> /etc/fstab on local pc:
> 192.168.1.10:/home /home nfs rw 0 0
> 192.168.1.10:/pub /pub nfs rw 0 0
>
> If I check the way its mounted, with "mount" it shows "rw" for both shares.
>
> Now, here is my problem: When I try to create/alter/delete a directory in
> /home on the local pc, everything works, like its supposed to. Meaning,
> userX can delete a directory /home/userX which belongs to him or alter its
> permissions. When I try to do the same in /pub, its not possible, but
> shows the error message "Read-only filesystem". Meaning, userX can not
> alter/delete a directory /pub/userX although it belongs to him. It doesnt
> matter, if I`m root or regular user.
>
> Server is Red Hat 8 running a 2.4.18-14 kernel with nfs-utils-1.0.1-2.80
>
> What am I missing ?
How is the file system mounted on the server? If it's mounted read-only
on the server, the NFS server can't add writability.
--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***
| |
|
| > How is the file system mounted on the server? If it's mounted read-only
> on the server, the NFS server can't add writability.
As I posted in a later message it mounted rwxr-xr-x for /home and for
/raid and for /pub
drwxr-xr-x 93 root root 4096 Jun 16 16:55 home
drwxr-xr-x 9 root root 4096 May 15 05:42 raid
lrwxrwxrwx 1 root root 10 Apr 18 2005 pub -> /raid/pub
/raid:
drwxrwxr-x 20 root root 4096 Aug 1 10:36 pub
No difference there between /home and /pub
Could it be, that the link is the cause of the problem ?
Thanks for your help,
DD.
| |
| Hajo Ehlers 2006-08-01, 7:26 pm |
| DD wrote:
>
> As I posted in a later message it mounted rwxr-xr-x for /home and for
> /raid and for /pub
> drwxr-xr-x 93 root root 4096 Jun 16 16:55 home
> drwxr-xr-x 9 root root 4096 May 15 05:42 raid
> lrwxrwxrwx 1 root root 10 Apr 18 2005 pub -> /raid/pub
>
> /raid:
> drwxrwxr-x 20 root root 4096 Aug 1 10:36 pub
>
> No difference there between /home and /pub
For clearence:
You have the following local filesystems
/home
/raid
/raid/pub
and a link from /pub -> /raid/pub
To access pub on a nfs client you must export /raid/pub and not any
kind of link.
Wonders that this even work for ro-access.
>...be, that the link is the cause of the problem ?
probaly yes . Check also on the server the /raid/pub directory security
setting BEFORE its get over mounted
hth
Hajo
| |
| Barry Margolin 2006-08-02, 1:24 am |
| In article <pan.2006.08.01.15.04.27.475909@rwth-aachen.de>,
DD <dominik.dierkes@rwth-aachen.de> wrote:
>
> As I posted in a later message it mounted rwxr-xr-x for /home and for
> /raid and for /pub
> drwxr-xr-x 93 root root 4096 Jun 16 16:55 home
> drwxr-xr-x 9 root root 4096 May 15 05:42 raid
> lrwxrwxrwx 1 root root 10 Apr 18 2005 pub -> /raid/pub
>
> /raid:
> drwxrwxr-x 20 root root 4096 Aug 1 10:36 pub
>
> No difference there between /home and /pub
Those are the directory permissions. I was talking about the mount
options. Show the output of "mount" on the server.
--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***
| |
|
| > Those are the directory permissions. I was talking about the mount
> options. Show the output of "mount" on the server.
Sorry. Didnt pay enough attention there obviously.
Here`s what mount says:
/dev/sdb1 on /home type ext3 (rw,usrquota)
/dev/sdc1 on /raid type ext3 (rw)
Has usrquota any effect on write permissions ???
I`d doubt that.
Thanks for your help,
DD.
| |
|
| > For clearence:
> You have the following local filesystems
> /home
> /raid
> /raid/pub
> and a link from /pub -> /raid/pub
Correct.
> To access pub on a nfs client you must export /raid/pub and not any
> kind of link.
/etc/exports:
/raid/pub 192.168.1.1/255.255.255.0(rw,async)
/home 192.168.1.1/255.255.255.0(rw,async)
I had previously left out the /raid part of the /pub export. Sorry for
that. But I do export /raid/pub and not the link to it.
> Check also on the server the /raid/pub directory security
> setting BEFORE its get over mounted
Same as /home.
Thanks for your help,
DD.
| |
| Hajo Ehlers 2006-08-02, 7:33 am |
|
DD wrote:
>
> Correct.
>
For trouble-shooting
1) Check the permission on /dev/sdc1 and /dev/sdb1
2) Unexport the share /raid/pub and umount /raid . AFTER that check the
permission on the directory /raid
3) Still have /raid umounted but export /raid. Mount raid on client and
redo a write test
4) Unexport /raid , mount /raid on the server and reexport /raid ( Not
/raid/pub ) and redo client test
Please post the results
Hajo
| |
|
| On Wed, 02 Aug 2006 02:42:06 -0700, Hajo Ehlers wrote:
>
> DD wrote:
>
> For trouble-shooting
> 1) Check the permission on /dev/sdc1 and /dev/sdb1
brw-rw---- 1 root disk 8, 17 Aug 31 2002 /dev/sdb1
brw-rw---- 1 root disk 8, 33 Aug 31 2002 /dev/sdc1
For the rest of your suggested tests:
I cannot do them during business hours, since the share is in use by our
users (well, reading from them is possible and writing or deleting stuff
is done by me as root). So I`ll have to wait. But I will report my results.
Thanks for your help,
DD.
| |
| John Blackburn 2006-08-03, 1:29 am |
| DD <dominik.dierkes@rwth-aachen.de> wrote in
news:pan.2006.08.02.12.05.18.288384@rwth-aachen.de:
> On Wed, 02 Aug 2006 02:42:06 -0700, Hajo Ehlers wrote:
>
>
> brw-rw---- 1 root disk 8, 17 Aug 31 2002 /dev/sdb1
> brw-rw---- 1 root disk 8, 33 Aug 31 2002 /dev/sdc1
>
> For the rest of your suggested tests:
> I cannot do them during business hours, since the share is in use by
> our users (well, reading from them is possible and writing or deleting
> stuff is done by me as root). So I`ll have to wait. But I will report
> my results.
>
> Thanks for your help,
> DD.
Do the users have the same UID's across servers?
| |
|
| > Do the users have the same UID's across servers?
Only one server, which is hosting the home directories, that every client
pc is mounting. Since the local /etc/passwd files on the clients do not
contain any of the users, there is only one instance, that determines the
uids: the server
DD.
| |
| Barry Margolin 2006-08-04, 1:26 am |
| In article < Xns98148E7A5D70Fjohndblackburntransp@203
.15.126.10>,
John Blackburn <john.d.blackburn@trnsprt.qld.qov.au> wrote:
> Do the users have the same UID's across servers?
Why would that matter? Remember, the error he's getting is "read-only
file system" -- that's not a problem with per-user permissions.
--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***
| |
|
| > So I`ll have to wait. But I will report my results.
Ok. Did all the tests and found out, that the problem seems to be limited
to some clients only. Before I thought, it was the same for all client
pcs, but I found some pcs, that dont show the read-only file system error.
Sorry, for not checking this before.
Thanks for all your help !!
With kind regards,
DD.
|
|
|
|
|