HP-UX 9.1, 9000/400 and alternate boot disks.....

[Craig D. Wilcox]

I've been recently tasked to come up with a good (meaning fast, reliable and replicable) method of doing a boot disk mirror for about 15 Series 400 workstations running 9.10. Since there's no real LVM stuff for the 400 workstations at 9.X, I'm a bit at a loss as to a good way to go!

The systems are test stations and ideally shouldn't be down for any longer than they need to. We've narrowed the solutions down to:

1) swap box - pre-setup machine to be swapped in as needed.

2) spare disk- an alternate boot disk ( 1H is the main boot disk, 2H would be the alternate). 2H should be identical ( or as identical as possible given the majority of application data is stored on the network ), so that if the machine's disk dies, the operator reboots, interrupts the sequence, chooses 2H as the boot device and is back up and running.

We're leaning towards 2, and using an external drive. Trouble is, how can I get an EXACT duplicate of the Main boot drive? Even in Single user state, there are open files to contend with, etc.

The ultimate solution I guess is to boot off a third drive, and copy the Main boot to the alternate boot using something like dd or cpio. There's still a make boot issue too to throw in there.

ANY ideas are much appreciated. Thanks!

[James A. Donovan]

I would try using the dd utility. I've done this in the past with some Solaris boxes that I needed to make identical to each other. Set if=/dev/rdsk/cXtYdZ and of=/dev/rdsk/cAtBdC, where "if" is the drive to be duplicated and "of" is the duplicate.

You would need to experiment with the setting of blocksize to determine what would be fastest for your environment.

In the end, you should end up with a duplicate disk, and only need to change some values (like hostname, ip address, etc...) before placing a new machine with a duplicate drive on the network

[Craig D. Wilcox]

Jim.. you're talking about booting off the 3rd alternate drive so that I have the 2 "live" (main boot and alternate boot ) drives not mounted and in theory with no open files right? Just trying to clarify your idea. I'm leaning that way, especially as I can use any OS ( I think ) to boot from on the 3rd disk, do the dd, and then test it.

Question.. will DD pick up the boot stuff so as to make the alternate boot disk ready to go in terms of being immediate bootable? or Will I have to do some tricks re: mkboot and all that?

Thanks!

[James A. Donovan]

I'm about 99% certain that you won't need to run any other utility.

Also, I dont see an issue with making your copy from the live boot disk onto a 2nd disk. At least as long as there is no other activity happening on the system at the time. Even though files may be "open", that is, referenced in memory, it's unlikely that their contents are going to change in any way. Especially if those open files are binaries. About the only files I could see being updated on an inactive system would be a few log files...maybe....

[Craig D. Wilcox]

I'll see what happens. Log files I can live without copying bit for bit, it's the apps and the general OS, and naturally the boot info stuff from mkboot and all.

Thanks for the help!

[Craig D. Wilcox]

here's the results:


internal drive C2235A (400M)
external drive C2490A_300 (2G)

single user mode
only the internal disk mounted

dd if=/dev/rdsk/cEd6s0 of=/dev/rdsk/cEd4s0 bs=1024

I didn't time it ( started it and left for the day )

the dd was complete this AM, and I rebooted, interrupted the boot, and had 1H (C2235) and 2H (C2490A_300) as bootable devices. Chose 2H and came up nicely.

Had a couple of issues:

1. on boot, the kernal complained of not enough swap available--that I needed to increase MAXSWAPCHUNKS by 328 in order for it to be happy

2. bdf and mount showed my boot device as /dev/root. A quick edit to the 2H /etc/checklist file fixed that issue

3. bdf shows the disk size identical to the internal one--same available, total etc. I think that may be the boot sector info, or some other file/setting.. ideas there?

Otherwise, it's up and working, and appears to be a good copy--full services, etc.. It's looking GREAT!

[Eugene Klaus]

Try executing fsck on disk 2 prior to usage.