NBX Hard Disk Backup and Replacement

NBX Hard Disk Backup and Replacement

This page is here since there is a total lack of support from 3com.

Warning! This does not work as is

If the hard disk on an NBX 100 dies or get corrupted to the point where it won't work, this may get you going again but it assuems you have made a backup first.

Note, this is a work in progress and may not work properly.

This assumes you have access to a few things.


Take the disk out of the NBX and put it in the PC. I've got a removable hard drive sled that allows me to quickly remove hard drives. The drive should be set to master/slave or what ever it takes to get it working on the PC. In the NBX it is set as Master or it may be set as the only drive. Under linux the drives are labeled /dev/hda, hdb, hdc, hdd. Mine is a slave on the second IDE channel so it is /dev/hdd.

Copy the disk to a linux file. dd if=/dev/hdd of=nbx_backup bs=4M This will copy the raw disk image. file nbx_backup should tell you the file is a partition table. ls -l nbx_backup will show you the size of the file. Some version of linux have a 2gb file size limit. You can use dd if=/dev/hdd of=nbx_b_1 bs=4M skip=512 will get the second 2gb on these systems.


Start with a fresh disk. if you are using an used drive, wipe it out if its much bigger than the backup image you have. Wipe the disk with dd if=/dev/zero of=/dev/hdd bs=4M. The section where the htfs partition must be clear or teh nbx may get into a funny state where i can't be fixed.

Copy the disk image(s) to the new disk. dd if=mnx_backup of=/dev/hdd bs=4M will do it. If the disk image is the same size, you should be able put it in the nbx and have it work. If it does work, use the nbx upgrade procedure to put a fresh copy of the operating system. Use the option to start with an empty database as well. Once it rebuilds you should be able to restore from your backups and after 3 reboots the system should be ready for use.

You may have to rebuild the htfs partiation. I've had good luck by just copying the boot sector and dos partition.

Put the drive in the NBX and turn it on. It should normally and give you a nbx100> prompt. If you get complaints about the disk having problmes from the htfsFsck program. You can kill it with the command td nbxTaskInit. You can type that while its displaying info. If your working on a corrupted system, you may need to type this command before the htfsFsck program locks up. If you make a typeo, you must send a real back space (ctrl-H) or a ctrl-C will delete the line to allow you to start over.

Make the htfs partition using the nbxMakeHtfsPartition. This will create the partition and create some directories. There is also a diskInit command and diskFormat may be useful but I don't know how it works. diskInit /htfs0 will reformat the htfs0 partition but only seems to work sometimes while nbxMakeHtfsParition always seems to work.

Next set up the basic IP network with the nbxIpConfig. Answer the questions for your network or take the defaults.

The last step is to restore the data. type cd "/htfs0" to get into the correct area of the disk. You can get a directory with ll or ll "/htfs0/R2_8_8" to list files in a subdirectory. Next type vxtar "xvf","/dos0/R2_8_8/htfs.tar" which will unpack the needed files. Reboot and you should be able to use the web browser interface with the address of

Then do a software upgrade. If you have a newer version, install it using the web interface and delete the version that you installed on the disk just in case it has unnoticed side effects.

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 This page was last updated Saturday, 01-Sep-2001 05:32:12 UTC Copyright 2000-2018 thogard™ is a trademark of Tim Hogard