Things like having to do the "low level format" of CKD is a lot of extra
work that's not strictly needed.
Consider what's happening.
The backing store of all contemporary DASD is fixed block (whether
spinning rust or solid state, same for either).
The storage system presents CKD on the channel by emulating tracks and
records on top of what is actually FBA.
Systems like Linux and CMS don't actually use tracks and records or
counts and keys, so they lay-down blocks of the same size (typically 4K
for 3390).
You could bypass the CKD emulation and simply have byte-for-byte
storage-to-system if the DASD frame presented (e.g.) 9336, and most can
do that. (In SCSI/FCP land, that's all there is, last I knew.)
VM (both CP and CMS) and Linux and VSE can all run from IPL to shutdown
on FBA DASD.
I have been told that for clustering VM wants CKD for some synchro
handshake magic. Seriously Endicott?!?!? (Other uses of the word
"cluster" come to mind.)
But in every other context, and especially for FCP, everything is fixed
blocks. There is no more "low level format". It's just not a thing.
This has been true for PC disks and all micro and mini systems for years.
In fact, the only time you'd "low level format" since the advent of
Linux was for a floppy.
In a fully FBA world, yeah, enlarge the partition, then 'resize2fs',
voi-la! Like Harry Potter said, "I love magic!".
-- R; <><
On 8/29/24 4:20 PM, Rick Troth wrote:
This is one reason why I keep saying we should do more with FBA and
less with CKD. But I'll defer that to a separate note.
When 'resize2fs' sees a block device with more space than the
filesystem consumes, it simply changes the counts in the master inode
(and/or whatever other magic it manages).
With CKD, the new space must be blocked. Gotta have a bunch of 4K, not
empty cylinders.
You say "the new 3390".
Did you DDR the old onto the first part of the new disk? If not, do so.
What I mean is, CMS FORMAT the new volume, and then DDR the existing
disk onto the start.
CMS FORMAT (of CKD) does both _high level_ (the CMS EDF filesystem,
which you'll discard) and _low level_ (the blocks).
That way, the new space out there will all be wonderfully pre-blocked.
Yay!
THEN again try 'fdisk' on the new disk.
The trick of deleting the partition and creating a new one is exactly
how I would do it.
Just be careful that the new partition starts at exactly the same
offset as the old one.
Then when you have the lovely new partition of the size you're after,
again run 'resize2fs' on it. It should "just work".
I really hope this helps.
-- R; <><
On 8/29/24 1:17 PM, Mark Pace wrote:
I'm looking for a way to increase the size of my root filesystem.
I want to copy it from a 3390-mod9 10017 cyls to a 3390-mod27 32760 cyls.
It has an EXT4 filesystem.
I tried to use the same procedure I used with a Ubunto PC new disk.
fdisk
deleted the partition
add a new partition with all the new space
resize2fs
But when I fdisk the new 3390 - it says no partitions exist.
I tried to resize2fs - it says, nothing to do.
Is there a procedure to accomplish this?
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