[Aboriginal] Building a floppy rescue set like BG did?

[Philip Rhoades]

Christopher,


On 2017-03-15 03:03, Christopher Barry wrote:
> On Tue, 14 Mar 2017 16:05:55 +1100
> Philip Rhoades <phil at pricom.com.au> wrote:
> 
>> People,
>> 
>> As an exercise, I want to create a VM image (or at least backup of all
>> the files with rsync) from a SCSI drive in an old Red Hat (NOT
>> Enterprise) v5.2 Linux 486 machine (circa 1999 that does have rsync on
>> it but it has protocol problems talking to my server).  The 486 has:
>> 
>> - an ISA Adaptec 1542 SCSI controller attached to a Seagate 2GB drive
>> with 6 partitions
>> 
>> - an ISA ne2000 network card
>> 
>> - a 1.44MB FD
>> 
>> So, to be able to create the image of the 2GB SCSI drive that is in
>> the 486, I need to boot the 486 on one or more floppy disks and dd the
>> /dev/sda drive over SSH to a file on my big Fedora 25 x86_64
>> workstation.  I now have Basic Linux booting from floppies but it is
>> still 2005 vintage and uses SSH1 and I haven't been able to get the
>> old Ciphers, MACs and KexAlgorithms working with my Fedora 25 x86_64
>> server
>> - so I still can't ssh or rsync to it from the 486.  BL does not have
>> any rshd that rsync could use . . so I am thinking that AL should be
>> more up to date but I will have to build my own system it seems.  I
>> got BG's disks going:
>> 
>>   http://www.giannone.ch/rescue/current
>> 
>> but they didn't have support for the SCSI controller - I sent him a
>> couple of emails (and even rang him from Australia!) about getting his
>> custom build scripts of AL to modify . . but he didn't get back to
>> me . .
>> 
>> Has anyone here already produced a floppy boot set?  I have just
>> cloned the git repo and am building for the 486 but it would be nice
>> if someone could make my learning curve less steep . .
>> 
>> Thanks!
>> 
>> Phil.
> 
> Q: does the 486 boot at all on it's own? That's not clear to me from
> this email. If it does boot, then I assume you are worried about open
> files not transferring.


Correct - RH5.2.


> If it can boot on it's own, then I also assume you can see the disk and
> and all the files and the network too.


Yes.


> If you have nc (netcat command) you can simply use dd over netcat to
> backup the system. It's the simplest way to backup a disk image to
> another host over the network.


Ah yes . .


> start nc listening on port 9000 for connections in a shell on the f25
> boxen first:
> 
> # nc -l -p 9000 | dd of=/somewhere/486-rh-backup.img
> It will hang there waiting...
> (-p may or may not be needed on your f25 box)
> 
> then on the 486, boot to single user mode with networking (if an
> option), or telinit S to get into single mode and start networking if
> needed.


Isn't that just Level 3?  Are you saying that after starting networking, 
the system is still in single-user mode?


> From the 486 command line, dd off the entire disk (I assume it's called
> sda here):
> 
> # dd if=/dev/sda | nc ip.of.fedora.box:9000
> 
> 
> This sends data in the clear though, no encryption.


Yep, no worries - it is just over the LAN.


> Being in single user
> mode, there will be very few if any important files open during the
> transfer (e.g. some logfiles may be truncated), and you should be fine.


Oh, OK - I will give it a shot!  Thanks!


> Here's the netcat source code if you need to build it on the 486.
> ftp://ftp.debian.org/debian/pool/main/n/netcat/netcat_1.10.orig.tar.bz2


I can't remember if it has netcat on there - I will have a look.  I 
think the SCSI drive is on the way out though - but I did manage to 
compile rsh - but that still didn't work for some reason . .

Even if netcat works - I am still interested in building a floppy-booted 
AL system!

Regards,

Phil.
-- 
Philip Rhoades

PO Box 896
Cowra  NSW  2794
Australia
E-mail:  phil at pricom.com.au