I hate this so much:

            Linux builtsowell 2.6.18-274.7.1.el5 #1 SMP Mon Oct 17 11:57:14 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux

            df -kh

            Filesystem            Size  Used Avail Use% Mounted on
            /dev/mapper/mpath0p2  8.8G  8.7G  90M  99% /
            /dev/mapper/mpath0p6  2.0G   37M  1.9G   2% /tmp
            /dev/mapper/mpath0p3  5.9G  670M  4.9G  12% /var
            /dev/mapper/mpath0p1  494M   86M  384M  19% /boot
            /dev/mapper/mpath0p7  7.3G  187M  6.7G   3% /home
            tmpfs                  48G  6.2G   42G  14% /dev/shm
            /dev/mapper/o10g.bin   25G  7.4G   17G  32% /app/SIP/logs
            /dev/mapper/o11g.bin   25G   11G   14G  43% /o11g
            tmpfs                 4.0K     0  4.0K   0% /dev/vx
            lunmonster1q:/vol/oradb_backup/epmxs1q1
                                  686G  507G  180G  74% /rpmqa/backup
            lunmonster1q:/vol/oradb_redo/bisxs1q1
                                  4.0G  1.6G  2.5G  38% /bisxs1q/rdoctl1
            lunmonster1q:/vol/oradb_backup/bisxs1q1
                                  686G  507G  180G  74% /bisxs1q/backup
            lunmonster1q:/vol/oradb_exp/bisxs1q1
                                  2.0T  1.1T  984G  52% /bisxs1q/exp
            lunmonster2q:/vol/oradb_home/bisxs1q1
                                   10G  174M  9.9G   2% /bisxs1q/home
            lunmonster2q:/vol/oradb_data/bisxs1q1
                                   52G  5.2G   47G  10% /bisxs1q/oradata
            lunmonster1q:/vol/oradb_redo/bisxs1q2
                                  4.0G  1.6G  2.5G  38% /bisxs1q/rdoctl2
            ip-address1:/vol/oradb_home/cspxs1q1
                                   10G  184M  9.9G   2% /cspxs1q/home
            ip-address2:/vol/oradb_backup/cspxs1q1
                                  674G  314G  360G  47% /cspxs1q/backup
            ip-address2:/vol/oradb_redo/cspxs1q1
                                  4.0G  1.5G  2.6G  37% /cspxs1q/rdoctl1
            ip-address2:/vol/oradb_exp/cspxs1q1
                                  4.1T  1.5T  2.6T  37% /cspxs1q/exp
            ip-address2:/vol/oradb_redo/cspxs1q2
                                  4.0G  1.5G  2.6G  37% /cspxs1q/rdoctl2
            ip-address1:/vol/oradb_data/cspxs1q1
                                  160G   23G  138G  15% /cspxs1q/oradata
            lunmonster1q:/vol/oradb_exp/epmxs1q1
                                  2.0T  1.1T  984G  52% /epmxs1q/exp
            lunmonster2q:/vol/oradb_home/epmxs1q1
                                   10G   80M   10G   1% /epmxs1q/home
            lunmonster2q:/vol/oradb_data/epmxs1q1
                                  330G  249G   82G  76% /epmxs1q/oradata
            lunmonster1q:/vol/oradb_redo/epmxs1q2
                                  5.0G  609M  4.5G  12% /epmxs1q/rdoctl2
            lunmonster1q:/vol/oradb_redo/epmxs1q1
                                  5.0G  609M  4.5G  12% /epmxs1q/rdoctl1
            /dev/vx/dsk/slaxs1q/slaxs1q-vol1
                                  183G   17G  157G  10% /slaxs1q/backup
            /dev/vx/dsk/slaxs1q/slaxs1q-vol4
                                  173G   58G  106G  36% /slaxs1q/oradata
            /dev/vx/dsk/slaxs1q/slaxs1q-vol5
                                   75G  952M   71G   2% /slaxs1q/exp
            /dev/vx/dsk/slaxs1q/slaxs1q-vol2
                                  9.8G  381M  8.9G   5% /slaxs1q/home
            /dev/vx/dsk/slaxs1q/slaxs1q-vol6
                                  4.0G  1.6G  2.2G  42% /slaxs1q/rdoctl1
            /dev/vx/dsk/slaxs1q/slaxs1q-vol3
                                  4.0G  1.6G  2.2G  42% /slaxs1q/rdoctl2
            /dev/mapper/appoem     30G  1.3G   27G   5% /app/em

Yet, I equally, if not quite a bit more, also hate this:

            SunOS solarious 5.10 Generic_147440-19 sun4u sparc SUNW,SPARC-Enterprise

            Filesystem             size   used  avail capacity  Mounted on
            kiddie001Q_rpool/ROOT/s10s_u8wos_08a  8G    7.7G    1.3G    96%    /
            /devices                 0K     0K     0K     0%    /devices
            ctfs                     0K     0K     0K     0%    /system/contract
            proc                     0K     0K     0K     0%    /proc
            mnttab                   0K     0K     0K     0%    /etc/mnttab
            swap                    15G   1.8M    15G     1%    /etc/svc/volatile
            objfs                    0K     0K     0K     0%    /system/object
            sharefs                  0K     0K     0K     0%    /etc/dfs/sharetab
            fd                       0K     0K     0K     0%    /dev/fd
            kiddie001Q_rpool/ROOT/s10s_u8wos_08a/var    31G   8.3G   6.6G    56%    /var
            swap                   512M   4.6M   507M     1%    /tmp
            swap                    15G    88K    15G     1%    /var/run
            swap                    15G     0K    15G     0%    /dev/vx/dmp
            swap                    15G     0K    15G     0%    /dev/vx/rdmp
            /dev/dsk/c3t4d4s0   3   20G   279G    41G    88%    /fs_storage
            /dev/vx/dsk/oracle/ora10g-vol1  292G   214G    73G    75%     /o10g
            /dev/vx/dsk/oec/oec-vol1    64G    33G    31G    52%    /oec/runway
            /dev/vx/dsk/oracle/ora9i-vol1   64G    33G    31G   59%    /o9i
            /dev/vx/dsk/home     23G    18G   4.7G    80%    /export/home
            /dev/vx/dsk/dbwork/dbwork-vol1 292G   214G    73G    92%    /db03/wk01
            /dev/vx/dsk/oradg/ebusredovol   2.0G   475M   1.5G    24%    /u21
            /dev/vx/dsk/oradg/ebusbckupvol   200G    32G   166G    17%    /u31
            /dev/vx/dsk/oradg/ebuscrtlvol   2.0G   475M   1.5G    24%    /u20
            kiddie001Q_rpool       31G    97K   6.6G     1%    /kiddie001Q_rpool
            monsterfiler002q:/vol/ebiz_patches_nfs/NSA0304   203G   173G    29G    86%    /oracle/patches
            /dev/odm                 0K     0K     0K     0%    /dev/odm

The people with the authority don't rotate logs or delete packages after install in my environment. Standards, remediation, cohesion...all fancy foreign words to me.

==============

How am I supposed to deal with / filesystem full issues across multiple platforms that have a devastating number of mounts?

On Red Hat el5, du -x apparently avoids traversal into other filesystems. While this may be so, it does not appear to do anything if run from the / directory.

On Solaris 10, the equivalent flag is du -d, which apparently packs no surprises, allowing Sun to uphold its legacy of inconvenience effortlessly.

(I'm hoping I've just been doing it wrong.)

I offer up for sacrifice my Frankenstein's monster. Tell me how ugly it is. Tell me I should download forbidden 3rd party software. Tell me I should perform unauthorized coreutils updates, piecemeal, across 2000 systems, with no single sign-on, no authorized keys, and no network update capability. Then, please help me make this bastard better:

            pwd
            /
            du * | egrep -v "$(echo $(df | awk '{print $1 "\n" $5 "\n" $6}' | \
            cut -d\/ -f2-5 | egrep -v "[0-9]|^$|Filesystem|Use|Available|Mounted|blocks|vol|swap")| \
            sed 's/ /\|/g')" | egrep -v "proc|sys|media|selinux|dev|platform|system|tmp|tmpfs|mnt|kernel" | \
            cut -d\/ -f1-2  | sort -k2 -k1,1nr | uniq -f1 | sort -k1,1n | cut -f2 | xargs du -shx | \
            egrep "G|[5-9][0-9]M|[1-9][0-9][0-9]M"

My biggest failure and regret is that it still requires a single character edit for Solaris:

            pwd
            /
            du * | egrep -v "$(echo $(df | awk '{print $1 "\n" $5 "\n" $6}' | \
            cut -d\/ -f2-5 | egrep -v "[0-9]|^$|Filesystem|Use|Available|Mounted|blocks|vol|swap")| \
            sed 's/ /\|/g')" | egrep -v "proc|sys|media|selinux|dev|platform|system|tmp|tmpfs|mnt|kernel" | \
            cut -d\/ -f1-2  | sort -k2 -k1,1nr | uniq -f1 | sort -k1,1n | cut -f2 | xargs du -shd | \
            egrep "G|[5-9][0-9]M|[1-9][0-9][0-9]M"

This will exclude all non / filesystems in a du search from the / directory by basically munging an egrepped df from a second pipe-delimited egrep regex subshell exclusion that is naturally further excluded upon by a third egrep in what I would like to refer to as "the whale." The munge-fest frantically escalates into some xargs du recycling where -x/-d is actually useful, and a final, gratuitous egrep spits out a list of directories that almost feels like an accomplishment:

Linux:

            54M     etc/gconf
            61M     opt/quest
            77M     opt
            118M    usr/  ##===\
            149M    etc
            154M    root
            303M    lib/modules
            313M    usr/java  ##====\
            331M    lib
            357M    usr/lib64  ##=====\
            433M    usr/lib  ##========\
            1.1G    usr/share  ##=======\
            3.2G    usr/local  ##========\
            5.4G    usr   ##<=============Ascending order to parent
            94M     app/SIP   ##<==\
            94M     app   ##<=======Were reported as 7gb and then corrected by second du with -x.

Solaris:

            63M     etc
            490M    bb
            570M    root/cores.ric.20100415
            1.7G    oec/archive
            1.1G    root/packages
            2.2G    root
            1.7G    oec

Guess what? It's really slow.

Edit: Are there any bash one-liner heroes out there than can turn my bloated abomination into divine intervention, or at least something resembling gingerly copypasta?