[Info-vax] New filesystem mentioned

[Dave Froble]

On 5/14/2019 9:58 AM, Bob Koehler wrote:
> In article <qbd262$ejt$1 at dont-email.me>, Dave Froble <davef at tsoft-inc.com> writes:
>>
>> The DLM is cluster aware, and any locks are respected over the entire
>> cluster.
>
>     There are no DLM calls in ZFS as it is distributed.  You'ld have to
>     add them.
>

Perhaps because no other OS (well, almost all) has a DLM.  At least that 
I'm aware of.  IBM Sysplex is most likely something similar, don't know.

Anyway, as I understand it, on VMS, the DLM and the ODS file systems are 
two separate and independent things.  Users can access files through a 
file system, and can use the DLM to determine whether a particular 
resource is available, or in use by another.

I don't know what is used in other environments to implement some form 
of locking with ZFS.  For that matter I don't know anything about ZFS. 
But if sharing files, then some form of locking is called for.  For any 
file system to be implemented on VMS, it's reasonable to assume that the 
DLM would be used for locking.

So, I don't understand the comment about DLM calls in ZFS?  Locking is 
not part of a file system, locking is used in the tools that access a 
file system.  Things such as a database, or RMS, or other such.

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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