[OpenAFS] AFS and Samba CTDB
Fabrizio Manfredi
fabrizio.manfredi@gmail.com
Thu, 6 Dec 2007 09:38:37 +0100
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Hi Christopher,
I start to work on it, I think in 1or 2 week I will have some information
(tips,performance..), at the moment I use samba without CTDB and I find is a
good solution for heterogeneous environment.
You can find example on:
http://www.beolink.org/index/conferences
The primary benefit of CTDB are :
- more simple solution for HA, with standard samba you can use a
combination of DFS (Microsoft) and operating system HA
- parallel transfer, with parallel file system you can improve transfer
performance ( the CTDB is primary
develop for GPFS)
Anyway the CTDB is still in beta phase...
Christopher Mason wrote:
>>
>> Has anyone out there who's attempted to use Samba CTDB (clustered
>> trivial database) to provide redundancy for serving of AFS volumes via
SMB?
>>
>> Are there issues in terms of the semantics Samba CTDB expects from a
>> filesystem versus what AFS provides?
>
>I have not used Samba CTDB but from what little I know, CTDB provides a
>distributed database which is used to maintain shared state information
>so that locks and file handles can be served from any machine the client
>communicates with.
>
>Samba is going to want to serve byte range locks which are not supported
>by AFS. This is why the Windows AFS clients contain a mapping from CIFS
>lock semantics to AFS semantics. This will not be provided by Samba.
Samba has a similar function (you can configure different level of lock),
you can start from oplock where everything is handle by samba to a mandatory
lock .. if you have some volumes that are used only from samba you can use
oplocks2 and you have perfect windows semantics handle a cross client.
>AFS of course will also require the Samba servers to have AFS tokens for
>each user if you are providing authenticated access. If so, those
>tokens will either have to be replicated across the cluster or obtained
>on demand. Again, I do not know if the Samba folks have provided any
>AFS specific functionality in this area.
Samba today act a kaserver, in some way is a trusted chain. If you have a
valid "windows authentication" the samba server can create automatically
the afs token. At the moment I don't know the state of CTDB..
bye manfred
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Hi Christopher,<br><br>I start to work on it, I think in 1or 2 week I will have some information (tips,performance..), at the moment I use samba without CTDB and I find is a good solution for heterogeneous environment. <br>
You can find example on:<br><a href="http://www.beolink.org/index/conferences">http://www.beolink.org/index/conferences</a><br><br><br>The primary benefit of CTDB are :<br> - more simple solution for HA, with standard samba you can use a combination of DFS (Microsoft) and operating system HA
<br> - parallel transfer, with parallel file system you can improve transfer performance ( the CTDB is primary <br>develop for GPFS) <br><br>Anyway the CTDB is still in beta phase...<br><br><br>Christopher Mason wrote:<br>
>><br>>> Has anyone out there who's attempted to use Samba CTDB (clustered<br>>> trivial database) to provide redundancy for serving of AFS volumes via SMB?<br>>><br>>> Are there issues in terms of the semantics Samba CTDB expects from a
<br>>> filesystem versus what AFS provides?<br>><br>>I have not used Samba CTDB but from what little I know, CTDB provides a<br>>distributed database which is used to maintain shared state information<br>>so that locks and file handles can be served from any machine the client
<br>>communicates with.<br>><br>>Samba is going to want to serve byte range locks which are not supported<br>>by AFS. This is why the Windows AFS clients contain a mapping from CIFS<br>>lock semantics to AFS semantics. This will not be provided by Samba.
<br><br>Samba has a similar function (you can configure different level of lock), you can start from oplock where everything is handle by samba to a mandatory lock .. if you have some volumes that are used only from samba you can use oplocks2 and you have perfect windows semantics handle a cross client.
<br><br>>AFS of course will also require the Samba servers to have AFS tokens for<br>>each user if you are providing authenticated access. If so, those<br>>tokens will either have to be replicated across the cluster or obtained
<br>>on demand. Again, I do not know if the Samba folks have provided any<br>>AFS specific functionality in this area.<br><br>Samba today act a kaserver, in some way is a trusted chain. If you have a valid "windows authentication" the samba server can create automatically the afs token. At the moment I don't know the state of CTDB..
<br><br>bye manfred <br>
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