UNIX for Dummies Questions & Answers

Hey all,

At my work we have an installation that runs on a Xenix System V coupled with a PLC.
Now I have to take a backup of the complete Hard Disk from the PC but have no idea how to manage this.

Could someone help me and tell me which steps I have to take.

Thanx.

PLC=Programmable Logic Controller? Presumably this is a 25-year old computer in some sort of production environment. Even power cycling something this old is high risk.

1) Make sure you have the unix root password.

2) Obtain a hardware and software inventory and find out what you have got.
Find original receipts, manuals, media etc. .
If it has a backup device, see if there are directions.

3) If you have several of these, check whether they are clones of a master system which has a backup device fitted.

4) Consider contacting the original suppliers.

5) Consider hiring a specialist data recovery company to make the backup.

Since Xenix compiled programs will run on the current version of SCO (either 5.0.7 or 6.0.0) all you really need to backup is the programs and data.
You could use tar to back up all this to diskettes, slow but easily accomplished.

Code:

tar ctv6  /usr /u    # backs up all of /usr and /u to 3-1/2 diskettes

Check /etc/default/tar for the number that corresponds to your device.

Code:

/dev/rfd0135ds18 is drive 0 (A), 135 tracks, 18 sectors per track. (1.44mb)
/dev/rfd096ds15 is drive 0 (A), 96 tracks, 15 sectors per track  (1.2mb)

Tar will automatically create multi disk volumes.
If you have a 5-1/4 diskette drive only, then you would probably be better off replacing it with a 3-1/2

You can duplicate the disk using Norton Ghost, however, depending upon the specific release of Xenix, only hard drives that are listed in the BIOS can be used.

The larger problem is the PLC, if it is connected using a specific purpose ISA or EISA card you are very unlikely to find a replacement PCI card that would use the same software.

@jgt: so it is possible to make a complete copy of the hard drive with norton ghost? Is norton ghost not only for making images of a windows PC?

ghost or not, there's various ways of making copies of the disk, but that depends what the hardware is. Depending on how old it is, it may not even be useful to do so.

You can make a duplicate of the Xenix partition using Norton Ghost, you would have to install the drive in a system running the appropriate DOS/Windows operating system. But, you cannot change the size of the partition, and, you probably would not be able to use the copied drive in the current machine.
The newest machine that you could use would likely be a P3 with both PCI and ISA slots.
I have assumed that the disk is IDE/MFM and not SCSI.
You could also add a second disk to the current system, and use dd to copy the contents of drive 0 to drive 1. The same problem of having the MB recognize a new disk still exists though.

Another way which is often used for forensics is to use dd and netcat to "pipe" the partition image to another system.

You do this by starting a netcat listener (nc -l -p <port>) on another system which has enough space to store an image of the XENIX disk or partition and on XENIX system do dd <dd options> | nc <hostname> <port>.