Mirroring a disk

Started by gtnicol, March 11, 2006, 06:22:08 am

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gtnicol

I have a couple of machines that have some 'interesting' data, and installed applications that I'd prefer not to lose. Ideally, I'd like to be able to make a copy of the disk that I could restore from onto another disk.

What's the best way to do this? I have a number of tape drives, DAT, QIC, etc.

gaspar

Quote from: "gtnicol"I have a couple of machines that have some 'interesting' data, and installed applications that I'd prefer not to lose. Ideally, I'd like to be able to make a copy of the disk that I could restore from onto another disk.

What's the best way to do this? I have a number of tape drives, DAT, QIC, etc.


I'd use native OS utilities to run backup/restore.
Or you can mount an external disk and use cpio to transfer the files (but will need to have extra care with links)
All have pros and cons.
The Next Admin guide has all the options listed with pros and cons.

Bye
Gaspar

Andreas

Quote from: "gtnicol"I have a couple of machines that have some 'interesting' data, and installed applications that I'd prefer not to lose. Ideally, I'd like to be able to make a copy of the disk that I could restore from onto another disk.


You can use the dump/restore thingy for a disk backup. For tar or cpio, wich need to interpret the filesystem i'm not shure if you get a real doublicate.

I'm using dump/restore for copying bootable harddrives on a target, wich can't be used with builddisk or the install CDs.

idylukewild

This is similar to a question I have been trying to find
an answer to for some time now. I'd like to replace my
1Gb drive with a 2Gb drive and don't want to loose all
of the applications on the original drive (I don't have
original media for the apps). I read the following from
one source on the Web:

"A NeXTcube Turbo, 32MB memory, with monochrome display  and an external Contemporary Cybernetics CY-2000 650MB MO drive...
I had many difficulties  installing OpenSTEP on a new harddisc, I finally gave up and  made a bitwise copy of the 424MB drive in the NeXTstation (I  happened to have a spare drive of exactly the same size) and  put that in the cube. It works :-)"

Can anybody explain how to make a bitwise copy of
the 1Gb disk onto the 2Gb disk I want to install in the
NeXT? Alternatively, does somebody know that it will not
work?

Thanks!

gtnicol

>Can anybody explain how to make a bitwise copy of
>the 1Gb disk onto the 2Gb disk I want to install in the
>NeXT? Alternatively, does somebody know that it will not
>work?

That's exactly the problem I have: a 660MB Maxtor disk that I'd a) like to create a backup of and b) duplicate onto a 1.3G seagate.

I believe cpio and tar have trouble creating a clean copy of things don't they? I haven't used them for a while but I seem to remember having trouble getting to a bootable duplicated disk.

gaspar

I does need a bit of hardware hands on but it works and people I know did the same..

Basically find an external scsi enclosure or double ended scsi flat cable, either way be prepared to opent the hood (cover) of the black slab.

Then boot from your regular disk and make sure the other one is visible, then you have to create the partitions on the new (bigger) hard drive,the trick is that the first partition must not be larger than 450 MB and the rest no more than 1.2 GB
Once you have all the partitions mount the first one and then using  the builddisk utility create a Nextstep partition and install the SW.

Then unplug your primary disk (old/small) swap it for the new one (make sure you keep the same SCSI Id using the jumpers on the disk) and boot from it..
Then you have to mount the other partitions and make them permanent (/etc/vfstab I think...)

Or you can use the BIOS command b sd(n,n,n) mach ... command to boot from the other hard drive still attached to your next, this way could be simpler but you need to understand those parameters ahead of time.

Thats how I made my 4-5 ?? GB hard drive work... my only problem is that I need to have a SCSI terminator.. oh well .. nobody sees that end anyway. I'm sorry I can't give you all the details but I can't remember.. I did all that like 3-4 years ago... I know it took me hours cause you need to understand how everything works...

Then once your new drive up and running do a backup and restore it to one of the partitions.

Bye
Gaspar

fidel

I'm in a similar boat. I have a slab that, for reasons yet unknown, won't boot. I've never booted it, so don't know much more about it than that... Anyway, the drive sounds healthy - it spins, it coos, it warbles, but it doesn't grind, growl, or groan, etc. - and I'd like, at the very least, to verify that there's something on it to boot to...

So, my questions:

Is it possible to mount/ does anyone have any experience mounting a NS drive - being SCSI - on a Mac (more particularly, what is the filesystem on the slab's drive -UFS? ext2? etc.)?

And, if I can create a bitwise image of the drive, and write it back to another, larger drive later, are there any 'gotchas' to look out for, especially wrt the config files now on the drive (disktab, for example)?

Oh, and has anyone combined the real with the virtual - taking a dd'd disk image and used it, reconstituted, with Virtual PC (any version) as the primary/boot drive?

Andreas

Quote from: "idylukewild"
Can anybody explain how to make a bitwise copy of
the 1Gb disk onto the 2Gb disk I want to install in the
NeXT? Alternatively, does somebody know that it will not
work?


I do a try but excuse my bad english:

Put the disk in an external case and attach it to a runnable system.  
Boot up

- mount the new hd for example to /mnt
- cd /mnt  (IMPORTANT!)
- run

    dump 0f - /dev/sd0a | restore -rf -

(all 0 are zeros, not "O"scars)
You have to verify before this if your bootdrive is /dev/sd0a (should be) and after that you have a clone on your second drive.

the goal of this is, you can create partitions to the limit (2GB for NS) and you can use harddrive that builddisk doesn't like.

idylukewild

Gaspar and Andreas-

Sorry not to respond sooner, but I didn't see your advice until today. Thanks for the information. I've got an external drive case which I've been using, so I plan to try your techniques.

Gaspar- Are you sure about the 450 MB limit for the for the boot drive? I keep reading elseware about a 2GB limit. If the 2GB limit is correct, then I can partition my 4GB drive into two equal partitions. Thanks for your reply.

Andreas- I am being 're-introduced' to unix, but am learning. I imagine the line you wrote
"dump 0f - /dev/sd0a | restore -rf -"
is the command to tell the computer to simultaneously dump and restore (through a pipe) the existing boot drive to the external drive that I have just mounted by hardware and software.

If I use your technique to make a "clone" of my existing 1GB boot drive on to my new drive, will my new drive have only 1GB usable space (like the old boot drive that was cloned)? Is there something I have to do first to the new 4GB drive that I mount externally in order to prepare it for the  cloning process.

After I install the 4GB drive in the NeXT computer, need I do anything with the software to get the NeXT to recognize the new drive as the boot drive? I am aware I should set the 4GB drive jumpers so it is designated SCSI #1.

Forgive me if my questions are too basic. I haven't used Unix (or Macro-11, or Fortran) in over 15 years. I'm looking forward to trying out what you advise. It would be great to have more room and also know all is not lost if the old drive fails! Thanks!

Andreas

Quote from: "idylukewild"
Andreas- I am being 're-introduced' to unix, but am learning. I imagine the line you wrote
"dump 0f - /dev/sd0a | restore -rf -"
is the command to tell the computer to simultaneously dump and restore (through a pipe) the existing boot drive to the external drive that I have just mounted by hardware and software.


Yes, you are dumping the drive /dev/sd0a to the drive you are standing now, because this you have to cd-ing to the "new" drive.

Quote
If I use your technique to make a "clone" of my existing 1GB boot drive on to my new drive, will my new drive have only 1GB usable space (like the old boot drive that was cloned)?


No, if you use "my" technic, you get the whole size of the pre-partitioned harddrive.

Quote
Is there something I have to do first to the new 4GB drive that I mount externally in order to prepare it for the  cloning process.


If it would accepted by builddisk you have nothing to do. If you get some funny results, for example builddisk think you have only ~30 MB free space on you new disk, you have to do the steps:
- /usr/etc/scsimodes
- create your own disktab
- use the "disk" command

see another thread for this

But at all, see what builddisk think. If it tells the whole size of your drive you can use this tool.

Quote
After I install the 4GB drive in the NeXT computer, need I do anything with the software to get the NeXT to recognize the new drive as the boot drive?


No. If the drive isn't supported by builddisk it could be that the bootprocess shown some wrong results, but the drive itself brings the whole capacity.
I'm using mostly 9 Gig drives with 4 partitions.

Quote
Forgive me if my questions are too basic.


Its not basic, its a little bit tricky as far, as builddisk doesn't accept your drive, because its too new or too big.

In addition, read this thread:
http://www.nextcomputers.org/forums/viewtopic.php?t=62

idylukewild

Thanks Andreas! That makes it clear and I will try it!