[Info-vax] NFS proxy database when booted from DVD?

[Craig A. Berry]

On 1/31/19 2:57 PM, Stephen Hoffman wrote:
> On 2019-01-31 20:09:41 +0000, Craig A. Berry said:
> 
>> ...I'm contemplating what it would take to restore one of these 
>> backups, such as to a brand new system with empty disk drives after 
>> the old system went up in smoke...
> 
> Boot OpenVMS off a customized USB or customized DVD—based off the 
> standard installation kit, with an added procedure and maybe with an 
> added menu item—and have that procedure use sftp to retrieve and stage 
> the savesets for restoration.

Using sftp or scp to fetch the savesets to local storage other than what
will be the target of the restore and use that as the source of the
restore does makes sense.  There is no such storage currently in the
picture, but it's a reasonable ask.

> Depending on how locked down the configuration is, the procedure could 
> perform the saveset restoration.
> 
> If you want to get more complex with the access credentials needed for 
> the backup server, have the procedure generate a key-pair and then 
> display the generated public key, and transfer that to the target server 
> during the recovery when the restoration is necessary.
> 
> Remember to provide a way to clobber the client known hosts entry, if 
> the backup server sshd identity might change.
> 
> NFS support on OpenVMS has tended to be somewhat less than robust.
> 
> If you want to use NFS and if you can't pre-populate the files for 
> read-only access, then you might have to figure out how to mount an LD 
> partition or similar using a memory-only section or paged or non-paged 
> pool or some such; an emulated disk device in memory sans backing 
> storage.  That's probably possible using a memory-resident section, but 
> I don't know that LD has support for that sort of a volatile device. 
> Generate and place anything that needs to be read-write on that pseudo 
> disk device, and aim some logical names at the files.  

Yes, I think that's it, but probably DECram, not LD.

$ mcr SYSMAN IO CONNECT MDA0:/DRIVER=SYS$MDDRIVER/NOADAPTER
$ initialize/structure=5/nohighwater/size=<someblocks> mda0 mda0
$ mount/system mda0 mda0
$ create/directory/owner=[system] mda0:[tcpip]
$ define/system/exec TCPIP$PROXY mda0:[tcpip]
$ tcpip create proxy
$ tcpip add proxy system /nfs=outgoing /uid=<n> /gid=<n> /host=<host>
$ tcpip mount dnfs0: /host=<host> /path=<path>

All of that from the DCL prompt while booted from DVD, or built into a
customized DVD or USB stick as suggested above.  This is starting to
sound like real work.

> But I wouldn't use NFS here.

I wouldn't either, but not doing so means asking for things I may or may
not get.