Windows Logical Disk Manager error

Windows Logical Disk Manager error

[Marcin Gibuła]

Hi, 
while using a disc partitioned with ldm the following error occures:

sda:<6>ldm_validate_vmdb(): VMDB and TOCBLOCK don't agree on the database 
size.
[LDM] sda1 sda2 sda3 sda4

One partition is then unaccessible (though it works in windows). Kernel 
version is 2.6.8.1, but the problem also seems to appear in earlier versions.

# mount -t ntfs /dev/sda1 /mnt/d
# ls /mnt/d
ls: reading directory /mnt/d: Input/output error

# dmesg
attempt to access beyond end of device
sda1: rw=0, want=58136241, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136240.
attempt to access beyond end of device
sda1: rw=0, want=58136242, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136241.
attempt to access beyond end of device
sda1: rw=0, want=58136243, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136242.
attempt to access beyond end of device
sda1: rw=0, want=58136244, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136243.
attempt to access beyond end of device
sda1: rw=0, want=58136245, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136244.
attempt to access beyond end of device
sda1: rw=0, want=58136246, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136245.
attempt to access beyond end of device
sda1: rw=0, want=58136247, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136246.
attempt to access beyond end of device
sda1: rw=0, want=58136248, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136247.
attempt to access beyond end of device
sda1: rw=0, want=58136241, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136240.
attempt to access beyond end of device
sda1: rw=0, want=58136242, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136241.
attempt to access beyond end of device
sda1: rw=0, want=58136243, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136242.
attempt to access beyond end of device
sda1: rw=0, want=58136244, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136243.
attempt to access beyond end of device
sda1: rw=0, want=58136245, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136244.
attempt to access beyond end of device
sda1: rw=0, want=58136246, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136245.
attempt to access beyond end of device
sda1: rw=0, want=58136247, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136246.
attempt to access beyond end of device
sda1: rw=0, want=58136248, limit=54138987
NTFS-fs error (device sda1): ntfs_end_buffer_async_read(): Buffer I/O error, 
logical block 58136247.
NTFS-fs error (device sda1): ntfs_readdir(): Reading index allocation data 
failed.

-- 
mg

Re: Windows Logical Disk Manager error

[Anton Altaparmakov]

On Thu, 2004-09-23 at 11:54, Marcin Gibuła wrote:
> while using a disc partitioned with ldm the following error occures:
> 
> sda:<6>ldm_validate_vmdb(): VMDB and TOCBLOCK don't agree on the database 
> size.
> [LDM] sda1 sda2 sda3 sda4

Can you compile in ldm debugging support and then send the full debug
output at boot time?

Also can you download the ldm tools
(http://linux-ntfs.sourceforge.net/downloads.html) and copy the ldm
database to a file and make it available to me?

To dump the database do:

download linux-ldm-0.0.8.tar.bz2 then:

tar xvjf linux-ldm-0.0.8.tar.bz2
cd linux-ldm-0.0.8/test
./ldminfo --copy /dev/sda
tar cvjf ldmdump.tar.bz2 sda.data sda.part

The created file ldmdump.tar.bz2 is what we need.

Thanks in advance.

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

Re: Windows Logical Disk Manager error

[Marcin Gibuła]

> Can you compile in ldm debugging support and then send the full debug
> output at boot time?

Here it goes:

SCSI device sda: 320173056 512-byte hdwr sectors (163929 MB)
SCSI device sda: drive cache: write back
 sda:<7>ldm_validate_partition_table(): Found W2K dynamic disk partition type.
ldm_parse_privhead(): Parsed PRIVHEAD successfully.
ldm_parse_privhead(): Parsed PRIVHEAD successfully.
ldm_parse_privhead(): Parsed PRIVHEAD successfully.
ldm_validate_privheads(): Validated PRIVHEADs successfully.
ldm_parse_tocblock(): Parsed TOCBLOCK successfully.
ldm_parse_tocblock(): Parsed TOCBLOCK successfully.
ldm_parse_tocblock(): Parsed TOCBLOCK successfully.
ldm_parse_tocblock(): Parsed TOCBLOCK successfully.
ldm_validate_tocblocks(): Validated TOCBLOCKs successfully.
ldm_parse_vmdb(): Parsed VMDB successfully.
ldm_validate_vmdb(): VMDB and TOCBLOCK don't agree on the database size.
ldm_parse_vblk(): Parsed VBLK 0x401 (type: 0x45) ok.
ldm_parse_vblk(): Parsed VBLK 0x406 (type: 0x51) ok.
ldm_parse_vblk(): Parsed VBLK 0x403 (type: 0x34) ok.
ldm_parse_vblk(): Parsed VBLK 0x408 (type: 0x32) ok.
ldm_parse_vblk(): Parsed VBLK 0x40a (type: 0x33) ok.
ldm_parse_vblk(): Parsed VBLK 0x500 (type: 0x51) ok.
ldm_parse_vblk(): Parsed VBLK 0x504 (type: 0x33) ok.
ldm_parse_vblk(): Parsed VBLK 0x448 (type: 0x33) ok.
ldm_parse_vblk(): Parsed VBLK 0x44a (type: 0x33) ok.
ldm_parse_vblk(): Parsed VBLK 0x506 (type: 0x33) ok.
ldm_parse_vblk(): Parsed VBLK 0x502 (type: 0x32) ok.
ldm_parse_vblk(): Parsed VBLK 0x527 (type: 0x33) ok.
ldm_parse_vblk(): Parsed VBLK 0x523 (type: 0x51) ok.
ldm_parse_vblk(): Parsed VBLK 0x525 (type: 0x32) ok.
ldm_parse_vblk(): Parsed VBLK 0x444 (type: 0x51) ok.
ldm_parse_vblk(): Parsed VBLK 0x446 (type: 0x32) ok.
ldm_parse_vblk(): Parsed VBLK 0x415 (type: 0x34) ok.
 [LDM] sda1 sda2 sda3 sda4
ldm_partition(): Parsed LDM database successfully.

> Also can you download the ldm tools
> (http://linux-ntfs.sourceforge.net/downloads.html) and copy the ldm
> database to a file and make it available to me?

I've sent it on your e-mail.

-- 
mg

Re: Windows Logical Disk Manager error

[Anton Altaparmakov]

On Thu, 2004-09-23 at 11:54, Marcin Gibuła wrote:
> Hi, 
> while using a disc partitioned with ldm the following error occures:
> 
> sda:<6>ldm_validate_vmdb(): VMDB and TOCBLOCK don't agree on the database 
> size.
> [LDM] sda1 sda2 sda3 sda4
> 
> One partition is then unaccessible (though it works in windows). Kernel 
> version is 2.6.8.1, but the problem also seems to appear in earlier versions.

Ok, I have now had the time to look at the ldm database you sent me. 
The problem is very simple.  You are using spanned volumes which are not
supported by the Linux LDM driver.  You need to use the software raid
(MD) driver in Linux to assemble the LDM partition devices (shown above)
into the correct MD devices and then mount the created md device(s). 
See linux-2.6/Documentation/filesystems/ntfs.txt for detailed
description of what you need to do.

The details you may want to know are that you have 4 volumes, three with
NTFS and one with FAT16:

Volume1: NTFS: Letter C in Windows: Size 10GiB
Volume2: NTFS: Letter D in Windows: Size 46GiB
Volume3: FAT16: Letter in Windows unknown: Size 28GiB
Volume6: NTFS: Letter in Windows unknown: Size 109GiB

Volume1 is a simple one partition volume which is the first LDM
partition on your other harddisk (i.e. the one you did not send me the
ldm dump from).  You can just mount that with the NTFS driver.

Volume2 is a two partition concatenated volume made up of partitions
sda1 (26GiB) and sda3 (20GiB) (in this order) on the disk you sent me
the ldm dump from.  This is why you get the errors when you try to mount
sda1.  It tries to access data that is outside sda1, i.e. in sda3, but
sda1 ends at the end of sda1 (obviously) so the data is not readable. 
You need to assemble sda1 and sda3 using the instructions in the ntfs
documentation (see above) and then mount the created MD device with the
ntfs driver.

Volume3 is a simple one partition volume which is the second LDM
partition on your other harddisk.  You can just mount that with the vfat
driver.

Volume6 is a two partition concatenated volume mad up of partitions sda4
(109GiB) and sda2 (32kiB!) (in this order!) on the disk you sent me the
ldm dump from.  You should assemble this as described for Volume2 and
then mount the created MD device with the ntfs driver.

btw. You can obtain all the above information yourself in the future by
running:
	linux-ldm-0.0.8/test/ldminfo --dump /dev/sda
And then putting the displayed info together.

Let me know how it goes.  Both success and failures are interesting to
me as I do not remember anyone actually having had spanned ldm volumes
before so it would be nice to know it all works...

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

Re: Windows Logical Disk Manager error

[Marcin Gibuła]

> Volume3 is a simple one partition volume which is the second LDM
> partition on your other harddisk.  You can just mount that with the vfat
> driver.

Yep, it's working.

> Volume6 is a two partition concatenated volume mad up of partitions sda4
> (109GiB) and sda2 (32kiB!) (in this order!) on the disk you sent me the
> ldm dump from.  You should assemble this as described for Volume2 and
> then mount the created MD device with the ntfs driver.

Maybe I should explain what is my disc layout...
Volume2 is one partition, and Volume6 is mounted as one of its directories, 
something like:

D:\  <- Volume2
D:\download <- Volume6

Volume6 works fine without using software raid though.  Volume2 does not.

> Let me know how it goes.  Both success and failures are interesting to
> me as I do not remember anyone actually having had spanned ldm volumes
> before so it would be nice to know it all works...

I've tried the following:

# mdadm --build /dev/md1 -l linear -n 2 /dev/sda1 /dev/sda3
mdadm: array /dev/md1 built and started.
# mount /dev/md1 /mnt/d
# ls /mnt/d
ls: reading directory /mnt/d: Input/output error

dmesg output:
NTFS volume version 3.1.
NTFS-fs error (device md1): ntfs_readdir(): Actual VCN (0x6e68dc76fa7923) of 
index buffer is different from expected VCN (0x4). Directory inode 0x5 is 
corrupt or driver bug.

-- 
mg

Re: Windows Logical Disk Manager error

[Anton Altaparmakov]

On Fri, 2004-10-01 at 00:49, Marcin Gibuła wrote:
> > Volume6 is a two partition concatenated volume mad up of partitions sda4
> > (109GiB) and sda2 (32kiB!) (in this order!) on the disk you sent me the
> > ldm dump from.  You should assemble this as described for Volume2 and
> > then mount the created MD device with the ntfs driver.
> 
> Maybe I should explain what is my disc layout...
> Volume2 is one partition, and Volume6 is mounted as one of its directories, 
> something like:
> 
> D:\  <- Volume2
> D:\download <- Volume6
> 
> Volume6 works fine without using software raid though.  Volume2 does not.

I would not advise you to use volume6 without the md driver.  You are
then missing the last 32kb off the end and you never know when they
might be needed and access to the volume might fall over just when you
expect it least.  Also the backup bootsector is in the last sector so
you are at present missing that and even worse something like chkdsk
could think "corrupt volume, lets fix it" and damage your volume because
you are missing the end.

> > Let me know how it goes.  Both success and failures are interesting to
> > me as I do not remember anyone actually having had spanned ldm volumes
> > before so it would be nice to know it all works...
> 
> I've tried the following:
> 
> # mdadm --build /dev/md1 -l linear -n 2 /dev/sda1 /dev/sda3
> mdadm: array /dev/md1 built and started.
> # mount /dev/md1 /mnt/d

Volume2 not working can have a possible explanation in that it might be
assembled incorrectly.  For example, Windows is using 512-byte blocks
but Linux 1024-byte blocks so if your first partition has an odd number
of sectors Windows will use the last sector whereas Linux will cut off
the last sector and hence all data in the second partition will be
shifted by 512-bytes in the array which you cause all data to appear
corrupt in the second part of the volume.  I have seen this happen in my
own experiments on the Windows NT4 fault tolerant linear raid volumes, I
have not done experiments with Windows 2k/xp LDM linear raid volumes. 
If this is the case you cannot use the md driver and are stuck I am
afraid.  At least I am not aware of any Linux utility/driver that will
allow you to work in this case.

Alternatively maybe Windows 2k/XP LDM linear raid volumes are using the
cluster size as the block size instead of 512-byte blocks.  If that were
the case and your cluster size is > 1024 bytes (very likely on such a
large volume, it is probably 4096 bytes) then the second part of the
volume is again misaligned when assembled but in the opposite
direction.  Fortunately you can fix this case by using the "--rounding="
parameter to mdadm.  So if you have a cluster size of 4k try
--rounding=4.  (If you don't know your cluster size enable debugging in
the ntfs driver and then do the mount and "dmesg | grep cluster_size"
will tell you the answer.  To enable debugging in the driver it must be
compiled with debugging enabled and you need to, as root, do: "echo 1 >
/proc/sys/fs/ntfs-debug" after loading the module if modular and before
doing the mount command.)

# ls /mnt/d
> ls: reading directory /mnt/d: Input/output error
> 
> dmesg output:
> NTFS volume version 3.1.
> NTFS-fs error (device md1): ntfs_readdir(): Actual VCN (0x6e68dc76fa7923) of 
> index buffer is different from expected VCN (0x4). Directory inode 0x5 is 
> corrupt or driver bug.

I have seen this particular error before and it was due to the volume
having been upgraded from FAT to NTFS (and the conversion utility
apparently had screwed up the vcns in at least one directory).  Running
"chkdsk /f" on it fixed it in that particular case (even though chkdsk
reported no errors, apparently it fixed them without telling anyone!). 
So this is worth trying before you start messing around with --rounding=
and mdadm.

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

Re: Windows Logical Disk Manager error

[Marcin Gibuła]

> I would not advise you to use volume6 without the md driver.  You are
> then missing the last 32kb off the end and you never know when they

Well, I can't even build it... mdadm failes and driver complains with
md: Dev sda2 smaller than chunk_size: 0k < 32k

Different chunk size doesn't make any difference.

> direction.  Fortunately you can fix this case by using the "--rounding="
> parameter to mdadm.  So if you have a cluster size of 4k try
> --rounding=4.  (If you don't know your cluster size enable debugging in
> the ntfs driver and then do the mount and "dmesg | grep cluster_size"
> will tell you the answer.  To enable debugging in the driver it must be
> compiled with debugging enabled and you need to, as root, do: "echo 1 >
> /proc/sys/fs/ntfs-debug" after loading the module if modular and before
> doing the mount command.)

According to ntfs driver output my cluster size is indeed 4kb, but it still 
failes to read mounted fs.

Error is now:
NTFS-fs error (device md1): ntfs_readdir(): Actual VCN (0x20006500680054) of 
index buffer is different from expected VCN (0x4). Directory inode 0x5 is 
corrupt or driver bug.

Oh, and my system (and kernel) is x86-64 if it matters.

> "chkdsk /f" on it fixed it in that particular case (even though chkdsk
> reported no errors, apparently it fixed them without telling anyone!).
> So this is worth trying before you start messing around with --rounding=
> and mdadm.

I've tried that. No effect though.

-- 
mg

Re: Windows Logical Disk Manager error

[Anton Altaparmakov]

On Fri, 2004-10-01 at 15:26, Marcin Gibuła wrote:
> > I would not advise you to use volume6 without the md driver.  You are
> > then missing the last 32kb off the end and you never know when they
> 
> Well, I can't even build it... mdadm failes and driver complains with
> md: Dev sda2 smaller than chunk_size: 0k < 32k
> Different chunk size doesn't make any difference.

That is a bug in the md driver then.

> > direction.  Fortunately you can fix this case by using the "--rounding="
> > parameter to mdadm.  So if you have a cluster size of 4k try
> > --rounding=4.  (If you don't know your cluster size enable debugging in
> > the ntfs driver and then do the mount and "dmesg | grep cluster_size"
> > will tell you the answer.  To enable debugging in the driver it must be
> > compiled with debugging enabled and you need to, as root, do: "echo 1 >
> > /proc/sys/fs/ntfs-debug" after loading the module if modular and before
> > doing the mount command.)
> 
> According to ntfs driver output my cluster size is indeed 4kb, but it still 
> failes to read mounted fs.
> 
> Error is now:
> NTFS-fs error (device md1): ntfs_readdir(): Actual VCN (0x20006500680054) of 
> index buffer is different from expected VCN (0x4). Directory inode 0x5 is 
> corrupt or driver bug.

So the number has changed.  Means it is aligning the two pieces
differently.  But still not correctly.  Actually, having looked at the
dump of your LDM database again, it is not rounding anything at all. It
behaves exactly like the NT4 fault tolerant arrays, i.e. it uses all
512-byte sectors to store data.

You can see it from:

Volume2 Size: 0x05AB2EA2 (46437 MB)
    Volume2-01
      Disk2-01   VolumeOffset: 0x00000000 Offset: 0x00000000 Length:
0x033A186B
      Disk2-02   VolumeOffset: 0x033A186B Offset: 0x033A18AA Length:
0x02711637

Disk2-01 contains 0x033a186B sectors == 5413987 in decimal an you can
see the number is odd and hence the Linux md driver cannot work as it
uses 1024 bytes minimum so it can never work.  )-:

Disk2-02 starts at the offset Disk2-01 stops and hence the Linux md
driver again cannot work.

Sorry but with current Linux md driver and tools it is not possible to
make your linear arrays work.

> Oh, and my system (and kernel) is x86-64 if it matters.

It doesn't.

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

Re: Windows Logical Disk Manager error

[Anton Altaparmakov]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 2929 bytes --]

On Fri, 1 Oct 2004, Anton Altaparmakov wrote:
> On Fri, 2004-10-01 at 15:26, Marcin Gibuÿÿa wrote:
> > > I would not advise you to use volume6 without the md driver.  You are
> > > then missing the last 32kb off the end and you never know when they
> > 
> > Well, I can't even build it... mdadm failes and driver complains with
> > md: Dev sda2 smaller than chunk_size: 0k < 32k
> > Different chunk size doesn't make any difference.
> 
> That is a bug in the md driver then.
> 
> > > direction.  Fortunately you can fix this case by using the "--rounding="
> > > parameter to mdadm.  So if you have a cluster size of 4k try
> > > --rounding=4.  (If you don't know your cluster size enable debugging in
> > > the ntfs driver and then do the mount and "dmesg | grep cluster_size"
> > > will tell you the answer.  To enable debugging in the driver it must be
> > > compiled with debugging enabled and you need to, as root, do: "echo 1 >
> > > /proc/sys/fs/ntfs-debug" after loading the module if modular and before
> > > doing the mount command.)
> > 
> > According to ntfs driver output my cluster size is indeed 4kb, but it still 
> > failes to read mounted fs.
> > 
> > Error is now:
> > NTFS-fs error (device md1): ntfs_readdir(): Actual VCN (0x20006500680054) of 
> > index buffer is different from expected VCN (0x4). Directory inode 0x5 is 
> > corrupt or driver bug.
> 
> So the number has changed.  Means it is aligning the two pieces
> differently.  But still not correctly.  Actually, having looked at the
> dump of your LDM database again, it is not rounding anything at all. It
> behaves exactly like the NT4 fault tolerant arrays, i.e. it uses all
> 512-byte sectors to store data.
> 
> You can see it from:
> 
> Volume2 Size: 0x05AB2EA2 (46437 MB)
>     Volume2-01
>       Disk2-01   VolumeOffset: 0x00000000 Offset: 0x00000000 Length:
> 0x033A186B
>       Disk2-02   VolumeOffset: 0x033A186B Offset: 0x033A18AA Length:
> 0x02711637
> 
> Disk2-01 contains 0x033a186B sectors == 5413987 in decimal an you can
> see the number is odd and hence the Linux md driver cannot work as it
> uses 1024 bytes minimum so it can never work.  )-:
> 
> Disk2-02 starts at the offset Disk2-01 stops and hence the Linux md
> driver again cannot work.
> 
> Sorry but with current Linux md driver and tools it is not possible to
> make your linear arrays work.

I should add an AFAIK here.  I am by no means familiar (enough) with EVMS, 
LVM1/2, and the kernel Device Mapper itself, to be able to tell if there 
isn't some clever way of making it work with existing drivers and tools...

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/

Re: Windows Logical Disk Manager error

[Marcin Gibuła]

> I should add an AFAIK here.  I am by no means familiar (enough) with EVMS,
> LVM1/2, and the kernel Device Mapper itself, to be able to tell if there
> isn't some clever way of making it work with existing drivers and tools...

Good news, when I did the following:

# dmsetup create test
0 54138987 linear /dev/sda1 0
54138987 40965687 linear /dev/sda3 0

# mount /dev/mapper/test /mnt/d
# ls /mnt/d

... it worked!
(the same with sda4 + sda2 volume, i've taken numbers from ldminfo output)

Maybe it's worth to update Documentation/filesystems/ntfs.txt :)

-- 
mg

Re: Windows Logical Disk Manager error

[Anton Altaparmakov]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1098 bytes --]

On Sat, 2 Oct 2004, Marcin [iso-8859-2] Gibu³a wrote:
> > I should add an AFAIK here.  I am by no means familiar (enough) with EVMS,
> > LVM1/2, and the kernel Device Mapper itself, to be able to tell if there
> > isn't some clever way of making it work with existing drivers and tools...
> 
> Good news, when I did the following:
> 
> # dmsetup create test
> 0 54138987 linear /dev/sda1 0
> 54138987 40965687 linear /dev/sda3 0
> 
> # mount /dev/mapper/test /mnt/d
> # ls /mnt/d
> 
> ... it worked!
> (the same with sda4 + sda2 volume, i've taken numbers from ldminfo output)
> 
> Maybe it's worth to update Documentation/filesystems/ntfs.txt :)

Great stuff!  Well done.  Thanks for letting me know.  It is definitely 
time for an update of Documentation/filesystems/ntfs.txt.  (-:

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/