misc/86388: periodic(8) daily should backup bsdlabel(8) / fdisk(8) disk labels

[Seklecki at FreeBSD.org]

>Number:         86388
>Category:       misc
>Synopsis:       periodic(8) daily should backup bsdlabel(8) / fdisk(8) disk labels
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Wed Sep 21 02:20:05 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Seklecki, Brian A.
>Release:        5.3 Releng
>Organization:
Collaborative Fusion, Inc.  / Spiritual Machines
>Environment:
FreeBSD soundwave 5.3-RELEASE-p20 FreeBSD 5.3-RELEASE-p20 #0: Wed Jul 27 16:03:34 EDT 2005     root at soundwave.collaborativefusion.com:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
      Open/NetBSD have periodic(8) (well, actually /etc/perdiodic) scripts to backup fdisk(8) and disklabel(8) output.  This is exceptionally useful in the event that you need to recover your system from an offsite storage tape backup to another facility on new (identical) hardware.  Without disk partition / slice layout information, you have no idea how your system was originally partitioned.

Of course, depending on whether you're using software or hardware RAID, you might not even know how your RAID was setup.  We also need a way to extract software RAID configurations (vinnum, geom, gmirror, CCD ex.) to a config file reference.  For example, RAIDFrame's raidctl(8)  has a nice "-G" flag:          
                                                                                                                                                                                                                            "-G dev  
Generate the configuration of the RAIDframe device in a                                                             format suitable for use with the -c or -C options."  

There is one caveat: If you're using software RAID CCD, you have your ccd.conf(5) and the output of the component disks` bsdlabel(8) using my solution to determine where on the disk the CCD slice began.

There's no way to backup hardware RAID configuration layouts until the OS has a unified RAID API (see OpenBSD's msic@ list for details on something coming in the next release there).
>How-To-Repeat:
      Sit around for a few weeks every year and brainstorm DRP (Disaster Recovery Planning) scnearios in a 100% FreeBSD environment.
>Fix:
      I wrote an ugly little script for periodic to accomplish this here initially, until someone commits a higher quality one to the fbsd src tree:

The script is viewable at the following URL as well:

http://digitalfreaks.org/~lavalamp/220.backup-bsdlabels


-------------
#!/bin/sh
#
# $FreeBSD: src/etc/periodic/daily/220.backup-bsdlablels******
#

# If there is a global system configuration file, suck it in.
#
if [ -r /etc/defaults/periodic.conf ]
then
    . /etc/defaults/periodic.conf
    source_periodic_confs
fi

case "$daily_backup_bsdlabels_enable" in
    [Yy][Ee][Ss])

    bak=/var/backups

    disks=`sysctl -n kern.disks`

    if [ -z "$disks"  ]; then
        echo '$daily_backup_disklabels_enable" is set but no disk probed by kernel.' \
        "perhaps NFS diskless client."
        rc = 2
    else

        for i in $disks; do

                # first order of business is to check for an existing backup-backup
                if [ -f $bak/fdisk.$i.bak ] ; then
                        rc=1
                        echo "rotating $bak/fdisk.$i.bak"
                        cp -p $bak/fdisk.$i.bak $bak/fdisk.$i.bak2 || rc=3
                fi

                echo "backing up fdisk for $i"

                fdisk $i > "$bak/fdisk.$i.bak" 2>/dev/null || rc=3

                # again exept now we have to get a list of patitions/slices
                # sparc64 can have...9 hopefully slices on a sunlabel?
                part_slices=$(echo /dev/${i}s[0-9])

                for j in $(echo "$part_slices" | sed 's/\/dev\///'); do
                        if [ -f $bak/disklabel.${j}.bak ] ; then
                                rc=1
                                echo "rotating $bak/disklabel.${j}.bak"
                                cp -p $bak/disklabel.${j}.bak $bak/disklabel.${j}.bak2 || rc=3
                        fi

                        echo "backing up disklabel for ${j}"
                        disklabel /dev/${j} > "$bak/disklabel.${j}.bak" 2>/dev/null || rc=3
                done
        done
    fi;;

    *)  rc=0;;
esac


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