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Old 01-26-2011, 07:50 AM
Rudi Ahlers
 
Default how to unmount an NFS share when the NFS server is unavailable?

On Wed, Jan 26, 2011 at 10:32 AM, Edo <ml2edwin@gmail.com> wrote:
> Hi,
>
> On 1/26/11 5:23 PM, Rudi Ahlers wrote:
>> Hi All,
>>
>> How do I unmount an NFS share when the NFS server is unaivalable?
>>
>> I tried "umount /bck" but it "hangs" indefinitely
>> "umount -f /bck" tells me the mount if busy and I can't unmount it:
>
> Try:
>
> *umount -f -l /bck
>
> HTH,
>
> --
>

Thanx, that worked

How does one mount an NFS share, to avoid system timeouts when the
remove NFS server is offline?



--
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________
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Old 01-26-2011, 09:41 AM
Lorenzo Quatrini
 
Default how to unmount an NFS share when the NFS server is unavailable?

Rudi Ahlers ha scritto:
> On Wed, Jan 26, 2011 at 10:32 AM, Edo <ml2edwin@gmail.com> wrote:
>
> How does one mount an NFS share, to avoid system timeouts when the
> remove NFS server is offline?
>
I would use a different approach: use autofs, then the share is mounted "on the
fly" only when needed, and unmounted after a while of not using it anymore.
Is this fine with your environment?

Regards
Lorenzo
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Old 01-26-2011, 10:26 AM
Edo
 
Default how to unmount an NFS share when the NFS server is unavailable?

Hi,

On Jan 26, 2011, at 5:50 PM, Rudi Ahlers <Rudi@SoftDux.com> wrote:

> On Wed, Jan 26, 2011 at 10:32 AM, Edo <ml2edwin@gmail.com> wrote:
>> Hi,
>>
>> On 1/26/11 5:23 PM, Rudi Ahlers wrote:
>>> Hi All,
>>>
>>> How do I unmount an NFS share when the NFS server is unaivalable?
>>>
>>> I tried "umount /bck" but it "hangs" indefinitely
>>> "umount -f /bck" tells me the mount if busy and I can't unmount it:
>>
>> Try:
>>
>> umount -f -l /bck
>>
>> HTH,
>>
>> --
>>
>
> Thanx, that worked
>
> How does one mount an NFS share, to avoid system timeouts when the
> remove NFS server is offline?
>

Mount? Or unmount?

If unmount, then, just create a simple script that will ping the
server and then run the above command if it doesn’t respond.

HTH,

--
- Edwin - mailto:ml2edwin@gmail.com
“The generous soul will itself be made fat, and the one freely watering
[others] will himself also be freely watered.”―Proverbs 11:25

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Old 01-26-2011, 10:35 AM
Rudi Ahlers
 
Default how to unmount an NFS share when the NFS server is unavailable?

On Wed, Jan 26, 2011 at 12:41 PM, Lorenzo Quatrini
<lorenzo.quatrini@gmail.com> wrote:
> Rudi Ahlers ha scritto:
>> On Wed, Jan 26, 2011 at 10:32 AM, Edo <ml2edwin@gmail.com> wrote:
>>
>> How does one mount an NFS share, to avoid system timeouts when the
>> remove NFS server is offline?
>>
> I would use a different approach: use autofs, then the share is mounted "on the
> fly" only when needed, and unmounted after a while of not using it anymore.
> Is this fine with your environment?
>


That won't really work. The NFS clients run cPanel and we need a way
for end-users to have full access to their backups all the time. We
used to run backup over FTP, but then when a client wanted to restore
data one of the techs first had to download it from the backup server
and then let the client restore it. So I'm trying to cut down on
unnecessary support tasks.



--
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________
CentOS mailing list
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http://lists.centos.org/mailman/listinfo/centos
 
Old 01-26-2011, 01:34 PM
Rudi Ahlers
 
Default how to unmount an NFS share when the NFS server is unavailable?

On Wed, Jan 26, 2011 at 4:10 PM, Paul Heinlein <heinlein@madboa.com> wrote:
> On Wed, 26 Jan 2011, Les Mikesell wrote:
>
>>> That won't really work. The NFS clients run cPanel and we need a
>>> way for end-users to have full access to their backups all the
>>> time. We used to run backup over FTP, but then when a client wanted
>>> to restore data one of the techs first had to download it from the
>>> backup server and then let the client restore it. So I'm trying to
>>> cut down on unnecessary support tasks.
>>
>> I don't see why the automounter wouldn't work for this, but you can
>> mount with the soft,bg options to keep from hanging.
>
> You need to be completely sure that 100% of your apps know how to
> handle I/O errors before using soft mounts.
>
> Errors in hard-mounted NFS filesystems will produce hanging
> applications, which are admittedly a pain, but the apps will stop
> issuing i/o calls until the filesystem returns. An app can never be
> fooled into think a write or read operation succeeded when it didn't.
>
> Soft-mounted filesystems, however, return error codes that
> applications can (and most often do) ignore, resulting in all sorts
> file corruption.
>
> --
> Paul Heinlein <> heinlein@madboa.com <> http://www.madboa.com/
> _______________________________________________


the problem I'm getting is that the NFS mount is for backups only, so
if it's off-line then no backups can be made, which I can live with
for the time being while it's being brought online again.

But, the problem I sit with is that other regular operations on the
local disk "hang" so to say, untill I manually unmount the NFS mount.
How do I get local operations to continue while the NFS mount if
faulty, but not unmounted?


--
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 01-26-2011, 10:26 PM
Les Mikesell
 
Default how to unmount an NFS share when the NFS server is unavailable?

On 1/26/2011 4:55 PM, Dr. Ed Morbius wrote:
>
> The specific solution is 'umount -fl<dir|device>'.
>
> The general solution's a little stickier.
>
> I'd suggest the automount route as well (you're only open to NFS issues
> while the filesystem is mounted), but you then have to maintain
> automount maps and run the risk of issues with the automounter (I've
> seen large production environments in which the OOM killer would
> arbitrarily select processes to kill ....).
>
> Monitoring of client and server NFS processes helps. If it's the filer
> heads which are failing, and need warrants it, look into HA failover
> options.
>
> Soft mounts as mentioned won't hange processes, but may result in data
> loss. This is most critical in database operations (where atomicity is
> assumed and generally assured by the DBMS). If the issue is one of
> re-running a backup job, and you can get a clear failure, risk would be
> generally mitigated.

Actually, since the original question involved access to backups, I
should have given my usual answer which is that backuppc is the thing to
use for backups and it provides a web interface for restores (you pick
the historical version you want and either tell it to put it back to the
original host or you can download a tarball through the browser). Very
nice for self-serve access. It does want to map complete hosts to
owners that have permission to access them but with a little work you
make different areas of a shared system look like separate hosts.

--
Les Mikesell
lesmikesell@gmail.com



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Old 01-27-2011, 05:57 AM
Rudi Ahlers
 
Default how to unmount an NFS share when the NFS server is unavailable?

On Thu, Jan 27, 2011 at 1:26 AM, Les Mikesell <lesmikesell@gmail.com> wrote:
> On 1/26/2011 4:55 PM, Dr. Ed Morbius wrote:
>>
>> The specific solution is 'umount -fl<dir|device>'.
>>
>> The general solution's a little stickier.
>>
>> I'd suggest the automount route as well (you're only open to NFS issues
>> while the filesystem is mounted), but you then have to maintain
>> automount maps and run the risk of issues with the automounter (I've
>> seen large production environments in which the OOM killer would
>> arbitrarily select processes to kill ....).
>>
>> Monitoring of client and server NFS processes helps. *If it's the filer
>> heads which are failing, and need warrants it, look into HA failover
>> options.
>>
>> Soft mounts as mentioned won't hange processes, but may result in data
>> loss. *This is most critical in database operations (where atomicity is
>> assumed and generally assured by the DBMS). *If the issue is one of
>> re-running a backup job, and you can get a clear failure, risk would be
>> generally mitigated.
>
> Actually, since the original question involved access to backups, I
> should have given my usual answer which is that backuppc is the thing to
> use for backups and it provides a web interface for restores (you pick
> the historical version you want and either tell it to put it back to the
> original host or you can download a tarball through the browser). Very
> nice for self-serve access. *It does want to map complete hosts to
> owners that have permission to access them but with a little work you
> make different areas of a shared system look like separate hosts.
>
> --
> * Les Mikesell
> * *lesmikesell@gmail.com
>
>
>
> _______________________________________________



BackupPC doesn't intergrate into cPanel.

--
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 01-27-2011, 06:08 AM
Rudi Ahlers
 
Default how to unmount an NFS share when the NFS server is unavailable?

On Thu, Jan 27, 2011 at 9:05 AM, John R Pierce <pierce@hogranch.com> wrote:
> On 01/26/11 10:57 PM, Rudi Ahlers wrote:
>>
>> BackupPC doesn't intergrate into cPanel.
>
>
> cpanel is pure crap.
>
>
>


And you are any better?


--
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 01-27-2011, 12:30 PM
Rudi Ahlers
 
Default how to unmount an NFS share when the NFS server is unavailable?

On Thu, Jan 27, 2011 at 3:00 PM, Les Mikesell <lesmikesell@gmail.com> wrote:
> On 1/27/11 12:57 AM, Rudi Ahlers wrote:
>>
>>>
>>> Actually, since the original question involved access to backups, I
>>> should have given my usual answer which is that backuppc is the thing to
>>> use for backups and it provides a web interface for restores (you pick
>>> the historical version you want and either tell it to put it back to the
>>> original host or you can download a tarball through the browser). Very
>>> nice for self-serve access. *It does want to map complete hosts to
>>> owners that have permission to access them but with a little work you
>>> make different areas of a shared system look like separate hosts.
>>>
>>
>> BackupPC doesn't intergrate into cPanel.
>
> Why does it have to integrate? It runs on a different machine. Can't you make a
> remote apache authenticate the same way as a cpanel user would to access its web
> interface?
>
> --
> * Les Mikesell



Sorry, I should have explained. cPanel is a web based control panel
which allows end users to control every aspect of their domain (Web,
stats, mail, files, databases, logs, DNS, etc) including backups.

It currently backs up everything over FTP, and works fairly well but
when a user wants to restore a broken website one of our techs needs
to download the backup from the FTP server, to the cPanel server and
then restore it on the client's behalf.

Thus, mounting the NFS share basically added enough storage to the
cPanel todo the backups "locally", and then the users can restore the
backups themselves by logging into cPanel. i.e. all the necessary
security checks are performed automatically.

But, If we use something like backupPC, then each user will need to be
created on the BackupPC server (which will be a nightmare) and he then
has to download the backup to his own PC first (some sites are several
GB's, into the 10's of GB's), which then means the backup will take
ages to restore.

With cPanel, everything happens on the server directly so it's very quick.


--
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 

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