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fbackup and NAS

Regular Advisor

fbackup and NAS



I have on an HP-UX 11.31 RISC server a DAT/DDS tape drive, and all of my backups are done through the fbackup command on this device. All is working fine, but recently someone told me about the availability of some hard drive space on a NAS available in our network.

This external volume has been made available for me as a NFS volume, or eventually also as a CIFS volume. In both cases my windows domain username was mandatory to read/write on this volume.


I'd like to do (almost) all of my backups on this NAS, but I don't know how to proceed. I hope I can reuse some of the backup scripts already created.


Can anybody please point me in the right direction with a few brief suggestion(s) ?


Thank you 





Patrick Wallek
Honored Contributor

Re: fbackup and NAS

fbackup has the ability to write to a file on disk.  Instead of specifying a tape device (for example - 'fbackup -f /dev/rmt/0m') you can specify a disk device (for example - 'fbackup -f /backup/dir/20130423.fbackup' ).


Here's an example where I'm backing up my /tmp directory to a file in /var/tmp:


# bdf /tmp
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol6 1048576 397320 648216 38% /tmp


# bdf /var
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol8 6160384 3813144 2337472 62% /var


# fbackup -f /var/tmp/test.fbackup -c /etc/fbackup.conf -i /tmp
fbackup(1004): session begins on Tue Apr 23 16:22:22 2013
fbackup(3024): writing volume 1 to the output file /var/tmp/test.fbackup
fbackup(3055): total file blocks read for backup: 764734
fbackup(3056): total blocks written to output file /var/tmp/test.fbackup: 772768


# ll /var/tmp/test.fbackup
-rw------- 1 root sys 395657216 Apr 23 16:23 /var/tmp/test.fbackup


Checking the header on the file written:


# frecover -V - -f /var/tmp/test.fbackup
Machine Identification:9000/800
System Identification:HP-UX
Release Identification:B.11.11
Node Identification:ftp
User Identification:root
Record Size:4194304
Time:Tue Apr 23 16:22:22 2013
Media Use:0
Volume Number:1
Checkpoint Frequency:8192
Fast Search Mark Frequency:5000
Index Size:100512
Backup Identification Tag:1626 1366752142


Getting the list of files from the fbackup INDEX:


# frecover -I /tmp/pwfile -f /var/tmp/test.fbackup


# wc -l /tmp/pwfile
1598 /tmp/pwfile


# head /tmp/pwfile

8192 1 /
8192 1 /tmp
8192 1 /tmp/!p4.d
36864 1 /tmp/!p4.d/ipf.p4:00000005
24576 1 /tmp/!p4.d/pfil.p4:00000083
29 1 /tmp/!p4.d/signature
1548288 1 /tmp/!p4.d/vmunix.p4:0000006d
96 1 /tmp/.AgentSockets
0 1 /tmp/.AgentSockets/A
0 1 /tmp/.VRTSisisshmem


When specifying a device file you may want to use unique files for each day, so you don't accidentally overwrite a backup you need.  For example, in a script:


FILE=$(date +%Y%m%d).fbackup

fbackup -f ${FILE} -c /etc/fbackup.conf -i /tmp



Regular Advisor

Re: fbackup and NAS



Thank you for the help, and for the complete procedure.

Anyway, I've readed elsewhere ( that a direct backup with fbackup to a NFS share is NOT suggested, for performance and security reasons. In this old discussion was suggested to use the remote magtape capability of "fbackup", but I think it is not my case since there is no HP-UX capabilities on the NFS server (it is a non-HP NAS).

Apart of this problem, what still remains is the authentication problem, since the NFS share can be root mounted from "my" server, but I cannot read or write on it, since for this permits I need to be logged on the NFS share as a Windows domain user.  


Has anybody of you (please!) another suggestion ?


I was thinking about the make_net_recovery utility; it can be launched to store all the file systems on the remote server, but I believe it cannot be used for regular backups. And, of course, the "authentication problem" will still remain.


Thank you



Honored Contributor

Re: fbackup and NAS

> Apart of this problem, what still remains is the authentication problem, since the NFS share can be root mounted

> from "my" server, but I cannot read or write on it, since for this permits I need to be logged on the NFS share as

> a Windows domain user.  


There is no such thing as "logging on the NFS share as a particular user": the NFS protocol simply does not work that way.


The NFS server may require a Kerberos-based NFS security mode, which probably means that the HP-UX system would have to be added to the Active Directory and receiving Kerberos tickets from it. In that case, write access would only be granted to Unix users holding a valid Kerberos ticket matching the appropriate AD user.


In addition, the NAS would also need to have some way of mapping the Unix UID of the user to the corresponding Windows account. Otherwise it is likely to regard all the incoming write operations as being done by the anonymous user (usually user "nobody" in Unix world, the closest equivalent in Windows terms would probably be the "guest" user).


Here are instructions for using Kerberos authentication with a Windows-based NFS server. They might be enlightening in your case too, as your NAS seems to be rather strongly Windows-oriented (at least in its current configuration):


Without more details on what your NAS actually is and how it is configured, it will be hard to give any more specific advice.



I think make_net_recovery requires that the remote server is an Ignite-UX server. It won't work with just any NFS server.


Anyway, a backup created by make_net_recovery is very suitable for restoring the server in an all-or-nothing fashion, but very inconvenient if you only need to restore a single filesystem or even a single file from backups.

If your server handles non-negligible amounts of data, you really want some way to take incremental backups, or the time and storage space requirements for your backups are going to be very inconvenient.

Regular Advisor

Re: fbackup and NAS

Thank you, really nice document about NFS. It seems I can authenticate easily on this windows-like-nfs server through Kerberos, I will test this in the next few days.

A (really last!) question: can anybody please give me an advice about a fbackup alternative to save backups on an NFS server ?