lquerpv is an undocumented “midlevel” LVM command in AIX. Usually you don’t need it and never use it, but it is used by many “high-level” LVM commands to get LVM information from a physical volume.

If you run the command without any parameters, you’ll get a short usage information:

# lquerypv
0516-108 lquerypv: PV identifier not entered.
Usage: lquerypv [-h /dev/PVname] | [-p PVid [-g VGid | -N PVname] [-scPnaDdAtY]]

The first way to use the command (lquerypv -h /dev/PVname) shows dump of the first 256 bytes of the selected disk:

# lquerypv -h /dev/hdisk0
00000000   C9C2D4C1 00000000 00000000 00000000  |................|
00000010   00000000 00000000 00000000 00000000  |................|
00000020   00000000 00000000 00000000 00000000  |................|
00000030   00000000 00000000 00000000 00000000  |................|
00000040   00000000 00000000 00000000 00000000  |................|
00000050   00000000 00000000 00000000 00000000  |................|
00000060   00000000 00000000 00000000 00000000  |................|
00000070   00000000 00000000 00000000 00000000  |................|
00000080   0000313A BB567908 00000000 00000000  |..1:.Vy.........|
00000090   00000000 00000000 00000000 00000000  |................|
000000A0   00000000 00000000 00000000 00000000  |................|
000000B0   00000000 00000000 00000000 00000000  |................|
000000C0   00000000 00000000 00000000 00000000  |................|
000000D0   00000000 00000000 00000000 00000000  |................|
000000E0   00000000 00000000 00000000 00000000  |................|
000000F0   00000000 00000000 00000000 00000000  |................|

What you see as marked in the output is PVID (ID of the physical volume), usually seen in lspv output. If you don’t have PVID in lspv output, or you have some unexpected PVID, or you have some strange errors, trying to import a volume group, you can check the real PVID on the physical volume, using the command above.

Now we’re coming to something not obvious. I think, one the most important UNIX concepts is “everything is a file”. If it is so, we can use any file name instead of PV name as the parameter to lquerypv. Let’s check:

# lquerypv -h /etc/hosts
00000000   23204942 4D5F5052 4F4C4F47 5F424547  |# IBM_PROLOG_BEG|
00000010   494E5F54 4147200A 23205468 69732069  |IN_TAG .# This i|
00000020   7320616E 20617574 6F6D6174 6963616C  |s an automatical|
00000030   6C792067 656E6572 61746564 2070726F  |ly generated pro|
00000040   6C6F672E 200A2320 200A2320 626F7336  |log. .#  .# bos6|
00000050   31442073 72632F62 6F732F75 73722F73  |1D src/bos/usr/s|
00000060   62696E2F 6E657473 74617274 2F686F73  |bin/netstart/hos|
00000070   74732031 2E32200A 2320200A 23204C69  |ts 1.2 .#  .# Li|
00000080   63656E73 6564204D 61746572 69616C73  |censed Materials|
00000090   202D2050 726F7065 72747920 6F662049  | - Property of I|
000000A0   424D200A 2320200A 2320434F 50595249  |BM .#  .# COPYRI|
000000B0   47485420 496E7465 726E6174 696F6E61  |GHT Internationa|
000000C0   6C204275 73696E65 7373204D 61636869  |l Business Machi|
000000D0   6E657320 436F7270 2E203139 38352C31  |nes Corp. 1985,1|
000000E0   39383920 0A232041 6C6C2052 69676874  |989 .# All Right|
000000F0   73205265 73657276 6564200A 2320200A  |s Reserved .#  .|

and it works.

Not always useful to look at the first 256 bytes of the file. How can we look at the next 256 bytes of the file? There is another undocumented option – we can specify, at which point we want to start looking at a file. But the address must be in hexadecimal form. To show the next 256 bytes we can run the following command:

# lquerypv -h /etc/hosts 100
00000100   23205553 20476F76 65726E6D 656E7420  |# US Government |
00000110   55736572 73205265 73747269 63746564  |Users Restricted|
00000120   20526967 68747320 2D205573 652C2064  | Rights - Use, d|
00000130   75706C69 63617469 6F6E206F 72200A23  |uplication or .#|
00000140   20646973 636C6F73 75726520 72657374  | disclosure rest|
00000150   72696374 65642062 79204753 41204144  |ricted by GSA AD|
00000160   50205363 68656475 6C652043 6F6E7472  |P Schedule Contr|
00000170   61637420 77697468 2049424D 20436F72  |act with IBM Cor|
00000180   702E200A 2320200A 23204028 23293437  |p. .#  .# @(#)47|
00000190   09312E32 20207372 632F626F 732F7573  |.1.2  src/bos/us|
000001A0   722F7362 696E2F6E 65747374 6172742F  |r/sbin/netstart/|
000001B0   686F7374 732C2063 6D646E65 742C2062  |hosts, cmdnet, b|
000001C0   6F733631 442C2064 32303037 5F343941  |os61D, d2007_49A|
000001D0   32203130 2F312F30 37203133 3A35373A  |2 10/1/07 13:57:|
000001E0   35320A23 2049424D 5F50524F 4C4F475F  |52.# IBM_PROLOG_|
000001F0   454E445F 54414720 0A23200A 2320434F  |END_TAG .# .# CO|

So we can look at the whole file, starting every time 256 bytes further. Nice attempt, but I would like to see a little bit more, than 256 bytes. The second undocumented argument let us specify how many bytes (in hex) we would like to see. E.g., to show first 512 bytes of the file we specify 0 as a starting point and 200 as a length of the excerpt.

# lquerypv -h /etc/hosts 0 200
00000000   23204942 4D5F5052 4F4C4F47 5F424547  |# IBM_PROLOG_BEG|
00000010   494E5F54 4147200A 23205468 69732069  |IN_TAG .# This i|
00000020   7320616E 20617574 6F6D6174 6963616C  |s an automatical|
00000030   6C792067 656E6572 61746564 2070726F  |ly generated pro|
00000040   6C6F672E 200A2320 200A2320 626F7336  |log. .#  .# bos6|
00000050   31442073 72632F62 6F732F75 73722F73  |1D src/bos/usr/s|
00000060   62696E2F 6E657473 74617274 2F686F73  |bin/netstart/hos|
00000070   74732031 2E32200A 2320200A 23204C69  |ts 1.2 .#  .# Li|
00000080   63656E73 6564204D 61746572 69616C73  |censed Materials|
00000090   202D2050 726F7065 72747920 6F662049  | - Property of I|
000000A0   424D200A 2320200A 2320434F 50595249  |BM .#  .# COPYRI|
000000B0   47485420 496E7465 726E6174 696F6E61  |GHT Internationa|
000000C0   6C204275 73696E65 7373204D 61636869  |l Business Machi|
000000D0   6E657320 436F7270 2E203139 38352C31  |nes Corp. 1985,1|
000000E0   39383920 0A232041 6C6C2052 69676874  |989 .# All Right|
000000F0   73205265 73657276 6564200A 2320200A  |s Reserved .#  .|
00000100   23205553 20476F76 65726E6D 656E7420  |# US Government |
00000110   55736572 73205265 73747269 63746564  |Users Restricted|
00000120   20526967 68747320 2D205573 652C2064  | Rights - Use, d|
00000130   75706C69 63617469 6F6E206F 72200A23  |uplication or .#|
00000140   20646973 636C6F73 75726520 72657374  | disclosure rest|
00000150   72696374 65642062 79204753 41204144  |ricted by GSA AD|
00000160   50205363 68656475 6C652043 6F6E7472  |P Schedule Contr|
00000170   61637420 77697468 2049424D 20436F72  |act with IBM Cor|
00000180   702E200A 2320200A 23204028 23293437  |p. .#  .# @(#)47|
00000190   09312E32 20207372 632F626F 732F7573  |.1.2  src/bos/us|
000001A0   722F7362 696E2F6E 65747374 6172742F  |r/sbin/netstart/|
000001B0   686F7374 732C2063 6D646E65 742C2062  |hosts, cmdnet, b|
000001C0   6F733631 442C2064 32303037 5F343941  |os61D, d2007_49A|
000001D0   32203130 2F312F30 37203133 3A35373A  |2 10/1/07 13:57:|
000001E0   35320A23 2049424D 5F50524F 4C4F475F  |52.# IBM_PROLOG_|
000001F0   454E445F 54414720 0A23200A 2320434F  |END_TAG .# .# CO|

Now using this secret knowledge and KornShell capabilities, we can write a simple oneliner to dump a file in hex:

# hd() { [ -f "$1" ] && lquerypv -h "$1" 0 $(printf "%0x" $(ls -l "$1" 2>/dev/null | awk '{print $5}')) || print -u2 "File $1 not found" ; }

# hd /etc/hosts
00000000   23204942 4D5F5052 4F4C4F47 5F424547  |# IBM_PROLOG_BEG|
00000010   494E5F54 4147200A 23205468 69732069  |IN_TAG .# This i|
00000020   7320616E 20617574 6F6D6174 6963616C  |s an automatical|
00000030   6C792067 656E6572 61746564 2070726F  |ly generated pro|
...

 

P.S. If you don’t like to write scripts and use undocumented commands, there is a documented hex viewer in AIX – od -cx.