Creating a bootable tape

[Stephen Keane]

I am trying to create a bootable tape for an HP-UX 11.11 9000/785 system. I can put a LIF on the front of the tape and run the ISL from it, but I don't know what hpux(1M) is looking for when I try the next stage. With a disk it would look for an HFS file system with a file on it (default /vmunix or /stand/vmunix depending upon your configuration). But a tape doesn't have a filesystem. The hpux(1M) man page does say that you can boot from a raw device, but doesn't say whether that device can be a tape, or what it is that should be written on the tape and in what format it should be written.

I've tried putting the kernel in the LIF on the front of the tape. I've tried dd'ing the kernel after the LIF.

[Pete Randall]

Stephen,

The easiest way to do this is to download and install Ignite and then run make_tape_recovery. This will give you a bootable tape that you can use to restore your root VG - very handy for disaster recovery.

http://www.software.hp.com/products/IUX/index.html


Pete

[Stephen Keane]

Yes, I am aware of that Pete, thanks. I am working at a much lower level and specifically DON'T want to use Ignite. I just wish HP would actually give some guidance as to what is actually on a raw device that you can boot from.

[Deoncia Grayson_1]

Take a look at this
7.2.4 Creating a Bootable System Backup
HP-UX doesn't have the mksysb command nor a command that all by itself does the same thing, but you can create a bootable image of a disk using DDS. The following is an example of backing up an internal SCSI disk drive at target number 6.

Shut down to single user mode to minimize system activity:
# shutdown 0

Clear any remaining data in the buffers:
# sync;sync

Use dd to copy the LIF boot area:
dd if=/usr/lib/uxbootlf of=/dev/rmt/0mn bs=2k

Again, sync the disk:
# sync;sync

Use dd to append to append the disk data:
# dd if=/dev/rdsk/c0t6d0 of=/dev/rmt/0m bs=64

The first dd puts a boot area on the tape, making it a bootable image. Once the boot image is on tape, the tape is not rewound. The next dd appends an image of the SCSI disk at address 6 to the tape. Be sure to use the appropriate disk device file.

Once created, the tape can be used to completely restore the disk:

Insert the tape into the DDS tape drive.
Go into the Boot Administration utility and boot to ISL from the tape. If your tape drive is at target 3, then your command would look like:
BOOT_ADMIN> b scsi.3.0 isl

Enter the following in response to the ISL prompt in order to restore to the internal drive at target 6:
ISL> hpux restore disc(scsi.6;0)

This command restores the disk image from the tape to the actual disk at scsi.6, destroying any existing data on the disk. There is a 2GB limit on the amount of data that can be restored. The tape and disk must be on the boot device interface.

or

Under HP-UX a bootable tape can be created. For HP-UX 9.X, the mkrs utility is used to do this. Under 10.X the copyutil is used.

Hope this helps

[Michael Roberts_3]

booting vmunix from the tape, without a ram filesystem, isn't going to get you very far.

Here is the contents from my make_tape_recovery
tape:

$mt rew

$dd if=/dev/rmt/0m of=/extra/tapeLif bs=10k
0+48217 records in
0+48217 records out

$lifls -l /extra/tapeLif
volume ISL10 data size 960926 directory size 3 04/12/06 01:08:16
filename type start size implement created
===============================================================
ISL -12800 16 242 0 04/12/06 01:08:16
AUTO -12289 264 1 0 04/12/06 01:08:16
INDEX BIN 272 1 0 04/12/06 01:08:16
CONFIG BIN 280 68 0 04/12/06 01:08:16
HPUX -12928 352 1024 0 04/12/06 01:08:16
FWWKAR6 BIN 1376 1 0 04/12/06 01:08:16
FWWKAR7 BIN 1384 1 0 04/12/06 01:08:16
FWWKAR8 BIN 1392 1 0 04/12/06 01:08:16
INSTALL -12290 1400 68184 0 04/12/06 01:08:22
INSTALLFS -12290 69584 49152 0 04/12/06 01:08:26
VINSTALLFS -12290 69584 49152 0 04/12/06 01:08:26
WINSTALLFS -12290 69584 49152 0 04/12/06 01:08:26
VINSTALL -12290 118736 73806 0 04/12/06 01:08:31
WINSTALL -12290 192544 83837 0 04/12/06 01:08:35
INSTCMDS BIN 276384 30244 0 04/12/06 01:08:36
RECCMDS BIN 306632 988 0 04/12/06 01:08:36
SYSCMDS BIN 307624 77795 0 04/12/06 01:08:39
SCRIPTS BIN 385424 45 0 04/12/06 01:08:39
VERSION BIN 385472 1 0 04/12/06 01:08:39
PAD BIN 385480 256 0 04/12/06 01:08:39


The kernel names ending in "INSTALL" causes the ram disk to be built, and the matching "INSTALLFS" to be loaded on to it. At that point the kernel just runs 'init' like usual, but in this case 'init' is Ignite code.

The boot syntax to instruct 'hpux' to load the kernel from the lif instead of from network or disk:

hpux (;0):kernelName

Note the ':' colon.

Loading software from the tape is the next step, and it is all in the Ignite code, not delivered anywhere else in the OS.

[Stephen Keane]

I got as far as

hpux boot (;0):FRED

But I get

Exec failed: Exec format error

FRED is simply created by using

lifcp -Knnn -b /stand/vmunix fredlif:FRED

(where nnn is calculated to put kernel on a 2k boundary)

I've tried creating fredlif:FRED as BIN, RAW, -12800, -12289, -12928 and BINARY, but none of them seem to work. Is the problem the lack of a RAM disk, or the format of the kernel itself?

[Stephen Keane]

OK, I've got a tape that kind of boots. It has a kernel on it and a minimal file system. It loads the kernel OK, complains about a couple of missing files (which are in the minimal file system) then tries turning the swap on (a bit difficult without a disk!) and stack traces before dying pitifully and rebooting. Progress of sorts.

[Michael Roberts_3]

If the kernel name does not end in 'INSTALL' it tries to do the regular vmunix things like turning on swap and accessing '/'.

If the kernel name _does_ end in INSTALL and has the ramfs driver in it:

nm INSTALL |grep -i ramfs
krs_free_ramfs_funcp| 11286848|extern|data |$BSS$
ramfs_init | 4095956|extern|entry |$CODE$
ramfs_return_pfds | 4096312|extern|entry |$CODE$
ramfsbegin_real | 11051588|extern|data |$SHORTDATA$
ramfsbegin_vir | 11051584|extern|data |$SHORTDATA$
ramfssize | 11051580|extern|data |$SHORTDATA$
reserve_ramfs_memory| 4096076|extern|entry |$CODE$
return_ramfs_memory | 4096448|extern|entry |$CODE$

Then the kernel will look for a ram filesystem image in the same location it was loaded from with the name ending in INSTALLFS
that matches the kernels name:

WINSTALL - kernel
WINSTALLFS - RAMFS image

So if the kernel is loaded from LIF, it will look in the LIF for the ramfs image.

[Stephen Keane]

Where doea it get the swap information from, all it has at that point is a kernel and the mini-filesystem that I've given it. I haven't told it to turn swap on, so wouldn't it be looking for some sort of configuration file to tell it what type of swap it has and where it is?

[Stephen Keane]

I've tried a boot tape with a kernel called FINSTALL and a ramdisk called FINSTALLFS and I still have the same problem, it's trying to enable swap and looking for a dump device, even when starting in single-user mode.