setup-storage fails on blank disk

[Derek Poon]

Me too.  I have been using the following script, placed in hooks/partition.LINUX, as a workaround.


#!/bin/bash

######################################################################
# If setup-storage encounters a disk to be partitioned, but the disk
# contains no partition table at all, it will give up.  To prevent
# such failures, this hook creates an empty partition table of the
# type specified in the setup-storage configuration file on any disk
# whose first 512 bytes are all null.
######################################################################

. /usr/lib/fai/subroutines

# Prints the absolute path of the disk configuration file, chosen based on
# the last applicable class to have a configuration file in
# /var/lib/fai/config/disk_config.
disk_config_file() {
    echo $classes | tr ' ' '\n' | tac | while read class ; do
        if [ -f "$FAI/disk_config/$class" ]; then
            echo "$FAI/disk_config/$class"
            break
        fi
    done
}

# Output contains one line per disk, with the device followed by the partition
# table type that it is supposed to have:
#
# /dev/sda gpt
# /dev/sda gpt-bios
# /dev/sdc msdos
want_partition_tables() {
    config_file=`disk_config_file`
    if [ -z "$config_file" ]; then
        # No suitable setup-storage config file
        exit 1
    fi
    awk -v disks="`/usr/lib/fai/fai-disk-info | sort`" '
        BEGIN {
            split(disks, dev);
        }

        $1 == "disk_config" && $2 ~ "disk.*" {
            sub("^disk", "", $2);
            for (i = 3; i <= NF; i++) {
                if (split($i, optionpair, ":")) {
                    if (optionpair[1] == "sameas") {
                        sub("^disk", "", optionpair[2]);
                        partition_table[$2] = partition_table[optionpair[2]];
                        if (dev[$2]) print "/dev/" dev[$2], partition_table[$2];
                        next;
                    } else if (optionpair[1] == "disklabel") {
                        partition_table[$2] = optionpair[2];
                        if (dev[$2]) print "/dev/" dev[$2], partition_table[$2];
                        next;
                    }
                }
            }

            # If no disklabel option is given, setup-storage uses "msdos" as
            # the default.
            if (dev[$2]) print "/dev/" dev[$2], "msdos";
        }
    ' "$config_file"
}

# Returns 0 if the first 512 bytes of the specified device are all null.
has_partition_table() {
    local dev="$1"
    perl -e "
        open D, '<', '$dev' and
        read D, \$buf, 512 and
        \$buf ne \"\\000\" x 512 or
        exit 1
    "
}

# For every disk in the setup-storage configuration, if there is no partition
# table apparent in the first 512 bytes, then we will create one of the
# appropriate type.
ensure_partition_tables_exist() {
    set -o pipefail
    want_partition_tables |
    while read dev table ; do
        if ! has_partition_table "$dev" ; then
            [ "$table" = "gpt-bios" ] && table=gpt
            echo "$dev has no partition table; making one of type $table"
            parted --script "$dev" mktable "$table"
        fi
    done
}

ensure_partition_tables_exist



> On Jan 4, 2018, at 7:12 AM, Brian Kroth <bpkroth at gmail.com> wrote:
> 
> Ages ago I recall having a similar problem to that as well.  I think it was a bug with the preserver_reinstall flag not working correctly with LVM setups on fresh disks.  Pretty sure I ended up writing a hack that executed early on in the classes phase to figure out if the disk was lacking a label (partition table) and then creating one and setting the reinstall flag to force the disk layout down.  Unfortunately I don't easily have access to that code anymore, else I'd share it.  Also, it may no longer be applicable.  setup-storage has changed a lot since then.
> 
> Cheers,
> Brian