[nflug] NFS noac option

Fri Apr 21 10:05:24 EDT 2006

    I wouldn't say there is a lot of hoops. Just sometimes I run into 
issues when the machine goes down It's stubborn about giving up hard 
mounts (hence my soft mounts). This is usually the case in the event of 
a problem, a server goes down or power outage. If my NFS box is down, my 
main concern is not the NFS clients having stubborn mounts. In my power 
outage scenario, I would like the machine to shutdown cleanly before the 
UPS dies, but that's easily worked around.

     I understand there may be better options out there, what I like is 
that it's supported out of the box by RedHat. I don't want to get into a 
situation where I'm recompiling software on 4 machines everytime a patch 
comes out, and have no idea how it will interract with my other software 
on the machine (that's what redhat network is for), and affect my 
production network . I try to keep as much out of the box software 
running for that reason (Courier-IMAP is the main exception).

Just my thinking anyways.

Justin

Justin Bennett
Network Administrator
Dynabrade, Inc.
8989 Sheridan Dr.
Clarence, NY 14031

Mark Musone wrote:
> I've been holding my tongue since the thread started, but I can't anymore :)
> Maybe one of the next meetings I'll talk about how completely horrible NFS
> is and it's 3,000 reasons why it's usually the worst option available. 
>
> Sorry..just ignore me..after reading all the hoops needed below just to get
> a simple email server to work, It was too much for me. One of the only even
> remotely acceptable uses for NFS is people's simple home directories to
> enable sharing between machines (but even that's pushing it).
>
> Ok, I'm going back to bed..
>
> -Mark
>
> -----Original Message-----
> From: nflug-bounces at nflug.org [mailto:nflug-bounces at nflug.org] On Behalf Of
> Sam Stern
> Sent: Thursday, April 20, 2006 4:27 PM
> To: nflug at nflug.org
> Subject: RE: [nflug] NFS noac option
>
>
>
>   
>> -----Original Message-----
>> From: Justin Bennett [mailto:Justin.Bennett at Dynabrade.com]
>> Sent: Thursday, April 20, 2006 02:46 PM
>> To: samstern at samstern.net; nflug at nflug.org
>> Subject: Re: [nflug] NFS noac option
>>
>> Thanks, I'll keep it in mind. We'll see if I run into any
>> issues with the hard mounts. I've set it with no options at
>> the moment we'll see how it goes. We also run maildir.
>>
>> We've been running with the 'soft' option for years, It was
>> added because the machine wouldn't shut down during a power
>> outage before the UPS died, hanging on unmouting drives. I
>> think origionally my problem was with courier still having
>> file locks when the machine is going down. A while back
>> changed my shutdown script run by the UPS to shutdown
>> sendmail, courier imap, samba, autofs, then the nfs services,
>>     
>
> <SNIP>
>
> Ahh. Okay I use Courier-MTA. The problem with Courier-IMAP and NFS (or iSCSI
> for that matter!) is two fold:
>
> 1) Famd is used to maintain a list of read items. So make a point of
> shutting that down as well -- perhaps having famd still running is causing
> your problems?
> 2) Courier uses caching of keywords, acls and the like so these files can
> become corrupted during an unclean shutdown
>
> I've found that it's easiest to merge this into your recovery scripts before
> courier starts to minimize problems:
>
> Find $home/Maildir/ -type d -name courierimapkeywords/ -exec rm -dfr {} \;
>
> Repeat for each of these files (putting these into a regexp made the email
> look funny so I did not):
> courierimapuiddb
> courierimapuiddb.lock
> sqwebmail-curcache.db1
> sqwebmail-curcnt
>
> This will force a re-read of the directories after an unclean shutdown by
> the imap clients. The forced reread can seems to solve a problem with
> Outlook seeming to get any new mail after an unclean shutdown.
>
> Please note that should never delete courierimapsubscribed for obvious
> reasons ;> This file can become corrupted in rare circumstances (like making
> a new folder JUST when the server crashes). This has oddly happened to me
> twice in the four years I've been using courier-mta. If the file becomes
> corrupted due to a unclean shutdown, edit the file and remove any lines that
> are corrupted. The file is not terminated by a new line; adding one has
> caused me problems in the past. The last character in the file is always a
> "." here is a sample for reference:
>
> mail:/home/sam/Maildir # hexdump -Cv courierimapsubscribed
> 00000000  49 4e 42 4f 58 0a 49 6e  62 6f 78 2e 53 65 6e 74
> |INBOX.Inbox.Sent|
> 00000010  0a 49 6e 62 6f 78 2e 44  72 61 66 74 73 0a        |.Inbox.Drafts.|
> 0000001e
>
>
> Further, take a look into this faq:
>
> http://www.courier-mta.org/?imapd.html
>
> Note the information on IMAP_USELOCKS
>
>
>
>
>
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