Adam,

zipl writes pointers to the kernel and the parmfile.  Which is why simply
updating the parmfile doesn't work, and can actually cause your system to
not find the parmfile, if the blocks used by the previous incarnation get
over-written.

Mark Post

-----Original Message-----
From: Adam Thornton [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, January 14, 2003 1:36 PM
To: [EMAIL PROTECTED]
Subject: Re: Backing up VM with linux facilities


On Tue, Jan 14, 2003 at 11:24:36AM -0600, Rick Troth wrote:
> > So, has anyone considered this?
>
> CKD volumes on the VM side make it tricky.   (the usual situation)
> If you have a wholly FBA based VM system  (sadly,  a rarity these days),
> then backing up VM volumes via Linux is trivial.   On FBA,  data blocks
> are always the same size and can be safely stored as a stream of bytes
> on any media.   Shops with VM, VSE, and/or Linux, and no MVS workload
> should consider FBA DASD.   VM does not need CKD.   Linux does
> not particularly *like* CKD.

Can Linux IPL from FBA these days?  I haven't tried in, like, a while.

Also, can anyone tell me how the parmline is encoded in the IPL record
on (CKD) DASD?  Specifically, is the parmline itself written into the
boot block (if so, where does that live?), or does the IPL record
contain a pointer to the block that holds the parmfile (which seems
dangerous)?  I'd assume it's the first, except that I don't see my
parmline in either ASCII or EBCDIC in the first 1M of the disk.

Adam

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