iostat -N doesn't report device mapper names

[Hugh Saunders]

Binary package hint: sysstat

Ubuntu Release: 8.04LTS
Package: sysstat
Package Version: 8.0.3-1ubuntu1
Expected: Using iostat -N statistics are shown against device mapper names (from /dev/mapper/*)
Actually Happened: Statistics are shown against devices labeled as "dm-n"

Further Information
=================

From iostat manpage:
    -N Display the registered device mapper names for any device mapper devices. Useful for viewing LVM2 statistics.

Reproduction Transcript:

admin-user@solok:~$ ls /dev/mapper
control sda5_crypt sdcard_crypt solok-root solok-rsnapshot solok-swap_1
admin-user@solok:~$ iostat
Linux 2.6.24-23-generic (solok) 09/04/09

avg-cpu: %user %nice %system %iowait %steal %idle
           1.18 0.20 1.06 2.88 0.00 94.68

Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 8.67 180.92 131.48 13312145 9674338
dm-0 25.77 180.84 131.48 13305939 9674328
dm-1 9.64 89.71 49.41 6600722 3635848
dm-2 0.14 0.02 1.09 1288 79896
dm-3 15.99 91.10 80.98 6703346 5958584
mmcblk0 1.40 4.78 58.15 351570 4278440
dm-4 7.86 4.75 58.15 349698 4278440

admin-user@solok:~$ iostat -N
Linux 2.6.24-23-generic (solok) 09/04/09

avg-cpu: %user %nice %system %iowait %steal %idle
           1.18 0.20 1.06 2.88 0.00 94.68

Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 8.67 180.92 131.48 13312145 9674338
dm-0 25.77 180.83 131.48 13305939 9674328
dm-1 9.64 89.71 49.41 6600722 3635848
dm-2 0.14 0.02 1.09 1288 79896
dm-3 15.99 91.10 80.98 6703346 5958584
mmcblk0 1.40 4.78 58.15 351570 4278440
dm-4 7.86 4.75 58.15 349698 4278440

[Chuck Short (zulcss)]

This actually the proper output for iostat since dm-0 is the information found in /sys/block/dm-0.

Regards
chuck