It sounds like you are looking for a shared file system like Sun's QFS?
Take a look here
Writes from multiple hosts go through the metadata server, basically,
that handles locking and update problems. I believe there are other
open source shared file systems around if you are trying to specifically
address the sharing problem.
David Olsen wrote:
>> On 27/08/2007, at 12:36 AM, Rainer J.H. Brandt wrote:
>>> Sorry, this is a bit off-topic, but anyway:
>>> Ronald Kuehn writes:
>>>> No. You can neither access ZFS nor UFS in that
>> way. Only one
>>>> host can mount the file system at the same time
>> (read/write or
>>>> read-only doesn't matter here).
>>> I can see why you wouldn't recommend trying this
>> with UFS
>>> (only one host knows which data has been committed
>> to the disk),
>>> but is it really impossible?
>>> I don't see why multiple UFS mounts wouldn't work,
>> if only one
>>> of them has write access. Can you elaborate?
>> Even with a single writer you would need to be
>> concerned with read
>> cache invalidation on the read-only hosts and
>> (probably harder)
>> ensuring that read hosts don't rely on half-written
>> updates (since
>> UFS doesn't do atomic on-disk updates).
>> Even without explicit caching on the read-only hosts
>> there is some
>> "implicit caching" when, for example, a read host
>> reads a directory
>> entry and then uses that information to access a
>> file. The file may
>> have been unlinked in the meantime. This means that
>> you need atomic
>> reads, as well as writes.
>> zfs-discuss mailing list
> It's worse than this. Consider the read-only clients. When you access a
> filesystem object (file, directory, etc.), UFS will write metadata to update
> atime. I believe that there is a noatime option to mount, but I am unsure as
> to whether this is sufficient.
> my 2c.
> This message posted from opensolaris.org
> zfs-discuss mailing list
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