On Jul 31, 2007, at 6:39 PM, Mark Hatle wrote:

> Thomas Lotterer wrote:
>> On Tuesday, 31. July 2007 at 3:04 pm, Jeff Johnson wrote:
>>> On Jul 31, 2007, at 5:02 AM, Thomas Lotterer wrote:
>>>> On Monday, 30. July 2007 at 9:26 pm, Jeff Johnson wrote:
>>>>> On Jul 30, 2007, at 2:58 PM, Thomas Lotterer wrote:
>>>>>> Decision:
>>>>>> - exclusively use Berkeley DB
>>>>>     3) NFS support
>>>>>
>>>> This can be rewritten to "networked filesystem support". BDB,  
>>>> SQLite
>>>> and any embedded DB require proper filesystem locking. Given the
>>>> environmental issues of a networked filesystem this will never work
>>>> reliably.
>>>>
>>> I don't disagree. However, an answer for client/server rpmdb  
>>> needs to
>>> be identified.
>>>
>> No use case for client/server rpmdb has been brought to my attention.
>
> You have a chassis w/ 8 blades.  1 blade acts as an internal server  
> for
> the other 7 blades.  It serves a kernel and filesystem to the other 7.
>
> The other 7 blades boot and have to do things related to the rpm
> database.  Over NFS the blades can blow up.. using RPC they will be  
> able
> to manipulate the database as necessary.
>
> That is a very common usage scenario in the Telecommunication  
> space.  7
> blades do the work, 1 (or 2) blades act as a control infrastructure.
>

And in the telco space one often desires 5 9's behavior.

I'm not sure that NFS write's qualify. Try NFS to multiple clients, then
random removes/writes on clients of  those files. The server than has  
multiple
copies of files with identical paths, but differing per-client  
content. That's
the NFS behavior I remember, not looked or cared for years.

Putting an rpmdb on NFS, with associated write's and rpm --rebuilddb
behavior, is likely to cause unexpected problems. And rpmdb database
problems are far more likely to be noticed than random write corruption
for, say, log files or backup's.

I've also debug'ed a handful of problems with rpm installing onto large
NFS trees, some that were quite reproducible. The last problem I  
remember
was at NCSU quite a while ago, should be in bugzilla.

I doubt NFS has gotten significantly better since I last looked.

73 de Jeff