[pkg-cryptsetup-devel] Bug#584174: cryptsetup create --offset does not document what units are used (appears to be 512-byte sectors)

Daniel Kahn Gillmor dkg at fifthhorseman.net
Wed Jun 2 00:11:01 UTC 2010


Package: cryptsetup
Version: 2:1.1.0-2.1
Severity: normal

cryptsetup(8) documents the --offset command as:

       --offset, -o
              start offset in the backend device.  This option is  only  rele‐
              vant for create action.

and cryptsetup luksDump reports a "Payload offset:"

but neither tool specifies the units.  Based on inspection with dd and
cmp, I believe the units used are 512-byte sectors.  It would be good
to have this documented clearly, though (e.g. that it does not depend
on the physical sector size of the backing device, since some newer
large disks are not using 512-byte sectors any more).

      --dkg

-- Package-specific info:
-- /proc/cmdline
BOOT_IMAGE=/vmlinuz-2.6.32-5-686 root=/dev/mapper/vg_pip0-root ro quiet

-- /etc/crypttab
md0_crypt /dev/md0 none luks

-- /etc/fstab
# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/mapper/vg_pip0-root /               ext3    defaults,noatime,errors=remount-ro 0       1
# /dev/sda1       /boot           ext3    defaults,noatime         0       2
UUID=775781da-4b41-4fb7-b95a-6ed507fdac3f       /boot           ext3    defaults,noatime         0       2
/dev/mapper/vg_pip0-home /home           ext3   defaults,noatime         0       2
/dev/mapper/vg_pip0-usr /usr            ext3    defaults,noatime         0       2
/dev/mapper/vg_pip0-var /var            ext3    defaults,noatime         0       2
/dev/mapper/vg_pip0-swap swap swap defaults 0 0
tmpfs /tmp tmpfs defaults,mode=1777,nosuid,nodev 0 0
/dev/mapper/vg_pip0-srv /srv ext3 defaults,noatime,nosuid,nodev,acl 0 2
/dev/mapper/vg_pip0-ftp /srv/ftp ext3 defaults,noatime,nosuid,nodev,acl 0 2

-- lsmod
Module                  Size  Used by
ufs                    56158  0 
qnx4                    5118  0 
hfsplus                61005  0 
hfs                    33093  0 
minix                  17814  0 
ntfs                  163917  0 
vfat                    6570  0 
msdos                   5118  0 
fat                    34912  2 vfat,msdos
jfs                   134682  0 
xfs                   417013  0 
exportfs                2618  1 xfs
reiserfs              176154  0 
ext4                  254973  0 
jbd2                   56091  1 ext4
ext2                   46293  0 
nls_utf8                 908  0 
isofs                  24608  0 
snd_seq_dummy            987  0 
arc4                     974  0 
ecb                     1405  0 
sco                     5857  2 
bridge                 32987  0 
stp                      996  1 bridge
bnep                    7444  2 
l2cap                  21705  3 bnep
crc16                   1027  2 ext4,l2cap
bluetooth              36327  5 sco,bnep,l2cap
binfmt_misc             4907  1 
fuse                   43758  1 
ath5k                 104118  0 
mac80211              123222  1 ath5k
ath                     6014  1 ath5k
cfg80211               87601  3 ath5k,mac80211,ath
led_class               1757  1 ath5k
loop                    9757  0 
snd_hda_codec_realtek   163214  1 
joydev                  6771  0 
snd_hda_intel          16675  2 
snd_hda_codec          46002  2 snd_hda_codec_realtek,snd_hda_intel
snd_hwdep               4054  1 snd_hda_codec
snd_pcm_oss            28671  0 
snd_mixer_oss          10461  1 snd_pcm_oss
snd_pcm                47214  3 snd_hda_intel,snd_hda_codec,snd_pcm_oss
snd_seq_midi            3576  0 
snd_rawmidi            12505  1 snd_seq_midi
snd_seq_midi_event      3684  1 snd_seq_midi
snd_seq                35463  3 snd_seq_dummy,snd_seq_midi,snd_seq_midi_event
i915                  218992  2 
uvcvideo               45226  0 
drm_kms_helper         18305  1 i915
snd_timer              12258  2 snd_pcm,snd_seq
snd_seq_device          3673  4 snd_seq_dummy,snd_seq_midi,snd_rawmidi,snd_seq
drm                   112020  3 i915,drm_kms_helper
eeepc_laptop           10104  0 
videodev               25545  1 uvcvideo
v4l1_compat            10250  2 uvcvideo,videodev
i2c_algo_bit            3497  1 i915
ftdi_sio               26968  0 
snd                    34363  15 snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
rfkill                 10264  4 bluetooth,cfg80211,eeepc_laptop
psmouse                44653  0 
usbserial              21847  1 ftdi_sio
i2c_core               12696  5 i915,drm_kms_helper,drm,videodev,i2c_algo_bit
tpm_tis                 5496  0 
tpm                     8137  1 tpm_tis
tpm_bios                3569  1 tpm
soundcore               3450  1 snd
rng_core                2178  0 
serio_raw               2916  0 
evdev                   5609  23 
pci_hotplug            18065  1 eeepc_laptop
video                  14605  1 i915
ac                      1640  0 
battery                 3782  0 
processor              26599  1 
output                  1204  1 video
snd_page_alloc          5045  2 snd_hda_intel,snd_pcm
button                  3598  1 i915
ext3                   94204  7 
jbd                    32169  1 ext3
mbcache                 3762  3 ext4,ext2,ext3
sha256_generic         10748  2 
aes_i586                6816  2 
aes_generic            25738  1 aes_i586
cbc                     2047  1 
usb_storage            30461  0 
dm_crypt                9127  1 
dm_mod                 46082  28 dm_crypt
raid1                  16103  1 
md_mod                 67177  2 raid1
sd_mod                 25869  3 
crc_t10dif              1012  1 sd_mod
ata_generic             2019  0 
ahci                   27246  0 
uhci_hcd               16057  0 
ata_piix               17640  2 
libata                115665  3 ata_generic,ahci,ata_piix
thermal                 9206  0 
ehci_hcd               27763  0 
scsi_mod              101401  3 usb_storage,sd_mod,libata
usbcore                98402  8 uvcvideo,ftdi_sio,usbserial,usb_storage,uhci_hcd,ehci_hcd
nls_base                4541  9 hfsplus,hfs,ntfs,vfat,fat,jfs,nls_utf8,isofs,usbcore
atl2                   17912  0 
thermal_sys             9378  3 video,processor,thermal


-- System Information:
Debian Release: squeeze/sid
  APT prefers testing
  APT policy: (500, 'testing'), (200, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.32-5-686 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages cryptsetup depends on:
ii  dmsetup                      2:1.02.45-1 The Linux Kernel Device Mapper use
ii  libc6                        2.10.2-9    Embedded GNU C Library: Shared lib
ii  libdevmapper1.02.1           2:1.02.45-1 The Linux Kernel Device Mapper use
ii  libpopt0                     1.16-1      lib for parsing cmdline parameters
ii  libuuid1                     2.16.2-0    Universally Unique ID library

cryptsetup recommends no packages.

Versions of packages cryptsetup suggests:
ii  dosfstools                    3.0.9-1    utilities for making and checking 
ii  initramfs-tools [linux-initra 0.94.4     tools for generating an initramfs
ii  udev                          154-1      /dev/ and hotplug management daemo

-- no debconf information





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