Re: [Qemu-discuss] Issue related to mounting /dev/nbd0p1

[Pascal]

disconnect and reconnect with *-f raw* option...

qemu-nbd --connect /dev/nbd0* --format=raw* /home/test/test.3.5.1b.debug/
test.3.5.1b.debug.raw


Le mar. 4 déc. 2018 à 14:32, ramakanth varala <address@hidden>
a écrit :

> address@hidden ~]# file
> /home/test/test.3.5.1b.debug/test.3.5.1b.debug.raw
> /home/test/test.3.5.1b.debug/test.3.5.1b.debug.raw: x86 boot sector;
> partition 1: ID=0x83, starthead 1, startsector 63, 208782 sectors;
> partition 2: ID=0x83, starthead 254, startsector 41913585, 16065 sectors,
> code offset 0x48
>
>
> On Tue, Dec 4, 2018 at 6:48 PM Pascal <address@hidden> wrote:
>
>> the partition does not appear and so, cannot be mounted.
>> moreover, if it appeared, it would have to be formatted before it could
>> be mounted...
>>
>> what is the result of the "file /home/test/test.3.5.1b.debug/
>> test.3.5.1b.debug.raw" command ?
>>
>> Le mar. 4 déc. 2018 à 13:51, ramakanth varala <address@hidden>
>> a écrit :
>>
>>> Hi Pascal..
>>>
>>> this works fine ....
>>>
>>> address@hidden ~]# qemu-nbd --connect /dev/nbd0
>>> /home/test/test.3.5.1b.debug/test.3.5.1b.debug.raw
>>>
>>> after this when i try to do mount like below...it fails..
>>>
>>>
>>> address@hidden ~]# mount /dev/nbd0p1
>>> /home/test/test.3.5.1b.debug/mnt/boot/
>>> mount: special device /dev/nbd0p1 does not exist
>>>
>>> but fdisk -l shows me this..
>>>
>>>
>>> address@hidden ~]# fdisk -l /dev/nbd0
>>>
>>> Disk /dev/nbd0: 21.4 GB, 21474836480 bytes
>>> 255 heads, 63 sectors/track, 2610 cylinders
>>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>>
>>>      Device Boot      Start         End      Blocks   Id  System
>>> /dev/nbd0p1               1          13      104391   83  Linux
>>> /dev/nbd0p2            2610        2610        8032+  83  Linux
>>>
>>>
>>> Hope we have some way ..which i can mount to partition .
>>>
>>> Thanks
>>> Rama Kanth
>>>
>>>
>>> On Tue, Dec 4, 2018 at 5:07 PM Pascal <address@hidden> wrote:
>>>
>>>> # qemu-nbd --connect */dev/nbd0* /home/test/test.3.5.1b.debug/
>>>> test.3.5.1b.debug.raw
>>>>
>>>> Le mar. 4 déc. 2018 à 12:32, ramakanth varala <
>>>> address@hidden> a écrit :
>>>>
>>>>> Hi  Pascal..
>>>>>
>>>>> I tried like below..
>>>>>
>>>>> address@hidden ~]# qemu-nbd -d /dev/nbd0
>>>>> /dev/nbd0 disconnected
>>>>>
>>>>> address@hidden ~]# qemu-nbd --connect /dev/nbd0p1
>>>>> /home/test/test.3.5.1b.debug/test.3.5.1b.debug.raw
>>>>> qemu-nbd: Could not access '/dev/nbd0p1': No such file or directory
>>>>>
>>>>>
>>>>> On Tue, Dec 4, 2018 at 4:55 PM ramakanth varala <
>>>>> address@hidden> wrote:
>>>>>
>>>>>> first time i got below..
>>>>>>
>>>>>> address@hidden ~]# kpartx -a /dev/ndb0
>>>>>> failed to stat() /dev/ndb0
>>>>>>
>>>>>> from second time onwards like below..
>>>>>>
>>>>>> address@hidden ~]# kpartx -a /dev/nbd0
>>>>>> device-mapper: resume ioctl failed: Invalid argument
>>>>>>
>>>>>>
>>>>>> On Tue, Dec 4, 2018 at 4:23 PM Jan Schermer <address@hidden> wrote:
>>>>>>
>>>>>>> Partigion is missing :-)
>>>>>>> try:
>>>>>>> kpartx -a /dev/ndb0
>>>>>>>
>>>>>>>
>>>>>>> > On 4 Dec 2018, at 11:35, ramakanth varala <
>>>>>>> address@hidden> wrote:
>>>>>>> >
>>>>>>> > Hi Pascal..
>>>>>>> >
>>>>>>> > yes its RW ...
>>>>>>> >
>>>>>>> > address@hidden ~]# fdisk -l /dev/nbd0
>>>>>>> >
>>>>>>> > Disk /dev/nbd0: 21.4 GB, 21474836480 bytes
>>>>>>> > 255 heads, 63 sectors/track, 2610 cylinders
>>>>>>> > Units = cylinders of 16065 * 512 = 8225280 bytes
>>>>>>> >
>>>>>>> >     Device Boot      Start         End      Blocks   Id  System
>>>>>>> > /dev/nbd0p1               1          13      104391   83  Linux
>>>>>>> > /dev/nbd0p2            2610        2610        8032+  83  Linux
>>>>>>> >
>>>>>>> > address@hidden ~]# ls -ltr /dev/nbd0*
>>>>>>> > brw-r----- 1 root disk 43, 0 Dec  4 11:06 /dev/nbd0
>>>>>>> >
>>>>>>> > address@hidden ~]# mount /dev/nbd0p1
>>>>>>> /home/test/test.3.5.1b.debug/mnt/boot/
>>>>>>> > mount: special device /dev/nbd0p1 does not exist
>>>>>>> >
>>>>>>> > address@hidden ~]# cat /proc/partitions
>>>>>>> > major minor  #blocks  name
>>>>>>> >
>>>>>>> >   8     0   62914560 sda
>>>>>>> >   8     1     104391 sda1
>>>>>>> >   8     2   62806117 sda2
>>>>>>> > 253     0   56655872 dm-0
>>>>>>> > 253     1    6127616 dm-1
>>>>>>> > 253     2     104391 dm-2
>>>>>>> > 253     3   20860402 dm-3
>>>>>>> >
>>>>>>> >
>>>>>>> > --Not sure..what's missing..
>>>>>>> >
>>>>>>> > Thanks
>>>>>>> > Rama Kanth
>>>>>>> >
>>>>>>> > On Tue, Dec 4, 2018 at 3:07 PM Pascal <address@hidden> wrote:
>>>>>>> >
>>>>>>> >> hi,
>>>>>>> >>
>>>>>>> >> you left fdisk without saving the changes (w before q), so there
>>>>>>> can't be
>>>>>>> >> two partitions.
>>>>>>> >> on the other hand, we should find the existing partition...
>>>>>>> >> there is a strange warning when fdisk starts: what is on the over
>>>>>>> side of
>>>>>>> >> nbd0 ?
>>>>>>> >> is /dev/nbd0 rw ?
>>>>>>> >> if you can't re-read the partitions table, can you disconnect
>>>>>>> /dev/nbd0 and
>>>>>>> >> then reconnect it ?
>>>>>>> >>
>>>>>>> >>
>>>>>>> >> Le lun. 3 déc. 2018 à 16:17, ramakanth varala <
>>>>>>> address@hidden>
>>>>>>> >> a écrit :
>>>>>>> >>
>>>>>>> >>> Hi ,
>>>>>>> >>>
>>>>>>> >>> I tried below steps .. still with some errors..
>>>>>>> >>>
>>>>>>> >>>
>>>>>>> >>> address@hidden ~]# fdisk /dev/nbd0
>>>>>>> >>>
>>>>>>> >>> The number of cylinders for this disk is set to 2610.
>>>>>>> >>> There is nothing wrong with that, but this is larger than 1024,
>>>>>>> >>> and could in certain setups cause problems with:
>>>>>>> >>> 1) software that runs at boot time (e.g., old versions of LILO)
>>>>>>> >>> 2) booting and partitioning software from other OSs
>>>>>>> >>>   (e.g., DOS FDISK, OS/2 FDISK)
>>>>>>> >>>
>>>>>>> >>> Command (m for help): n
>>>>>>> >>> Command action
>>>>>>> >>>   e   extended
>>>>>>> >>>   p   primary partition (1-4)
>>>>>>> >>> p
>>>>>>> >>> Partition number (1-4): 1
>>>>>>> >>> Partition 1 is already defined.  Delete it before re-adding it.
>>>>>>> >>>
>>>>>>> >>> Command (m for help): d
>>>>>>> >>> Partition number (1-4): 1
>>>>>>> >>>
>>>>>>> >>> Command (m for help): d
>>>>>>> >>> Selected partition 2
>>>>>>> >>>
>>>>>>> >>> Command (m for help): p
>>>>>>> >>>
>>>>>>> >>> Disk /dev/nbd0: 21.4 GB, 21474836480 bytes
>>>>>>> >>> 255 heads, 63 sectors/track, 2610 cylinders
>>>>>>> >>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>>>>>> >>>
>>>>>>> >>>     Device Boot      Start         End      Blocks   Id  System
>>>>>>> >>>
>>>>>>> >>> Command (m for help): n
>>>>>>> >>> Command action
>>>>>>> >>>   e   extended
>>>>>>> >>>   p   primary partition (1-4)
>>>>>>> >>> p
>>>>>>> >>> Partition number (1-4): 1
>>>>>>> >>> First cylinder (1-2610, default 1):
>>>>>>> >>> Using default value 1
>>>>>>> >>> Last cylinder or +size or +sizeM or +sizeK (1-2610, default
>>>>>>> 2610): 4
>>>>>>> >>>
>>>>>>> >>> Command (m for help): n
>>>>>>> >>> Command action
>>>>>>> >>>   e   extended
>>>>>>> >>>   p   primary partition (1-4)
>>>>>>> >>> p
>>>>>>> >>> Partition number (1-4): 2
>>>>>>> >>> First cylinder (5-2610, default 5):
>>>>>>> >>> Using default value 5
>>>>>>> >>> Last cylinder or +size or +sizeM or +sizeK (5-2610, default
>>>>>>> 2610):
>>>>>>> >>> Using default value 2610
>>>>>>> >>>
>>>>>>> >>> Command (m for help): p
>>>>>>> >>>
>>>>>>> >>> Disk /dev/nbd0: 21.4 GB, 21474836480 bytes
>>>>>>> >>> 255 heads, 63 sectors/track, 2610 cylinders
>>>>>>> >>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>>>>>> >>>
>>>>>>> >>>     Device Boot      Start         End      Blocks   Id  System
>>>>>>> >>> /dev/nbd0p1               1           4       32098+  83  Linux
>>>>>>> >>> /dev/nbd0p2               5        2610    20932695   83  Linux
>>>>>>> >>>
>>>>>>> >>> Command (m for help): q
>>>>>>> >>>
>>>>>>> >>> address@hidden ~]# blockdev --rereadpt /dev/nbd0
>>>>>>> >>> BLKRRPART: Invalid argument
>>>>>>> >>> address@hidden ~]# ls /dev/nbd0
>>>>>>> >>> /dev/nbd0
>>>>>>> >>> address@hidden ~]# ls /dev/nbd0*
>>>>>>> >>> /dev/nbd0
>>>>>>> >>>
>>>>>>> >>>
>>>>>>> >>>
>>>>>>> >>> Thanks
>>>>>>> >>> Rama Kanth
>>>>>>> >>>
>>>>>>> >>> On Fri, Nov 30, 2018 at 6:48 PM Pascal <address@hidden>
>>>>>>> wrote:
>>>>>>> >>>
>>>>>>> >>>> do not create nodes manually but with fdisk on nbd0 :
>>>>>>> >>>>
>>>>>>> >>>> # fdisk /dev/nbd0
>>>>>>> >>>> ## now create your partitions in fdisk
>>>>>>> >>>> ## use w to write changes and q to quit fdisk
>>>>>>> >>>>
>>>>>>> >>>> # blocdev --rereadpt /dev/nbd0
>>>>>>> >>>>
>>>>>>> >>>> # ls /dev/nbd0*
>>>>>>> >>>> ## you will now have /dev/nbd0, /dev/nbd0p1 and /dev/nbd0p2
>>>>>>> >>>>
>>>>>>> >>>> if this is not the case while the fdisk command ended without
>>>>>>> error :
>>>>>>> >>>>
>>>>>>> >>>> # sync
>>>>>>> >>>> # qemu-nbd -d /dev/nbd0
>>>>>>> >>>> # qemu-nbd -c /dev/nbd0 /the/target
>>>>>>> >>>>
>>>>>>> >>>>
>>>>>>> >>>> Le ven. 30 nov. 2018 à 14:04, ramakanth varala <
>>>>>>> >>>> address@hidden>
>>>>>>> >>>> a écrit :
>>>>>>> >>>>
>>>>>>> >>>>> Hi Pascal & Jakob,
>>>>>>> >>>>>
>>>>>>> >>>>> I started from first .
>>>>>>> >>>>>
>>>>>>> >>>>> I created manully the partitions as below
>>>>>>> >>>>>
>>>>>>> >>>>>   27  mknod /dev/nbd0p1 b 1 4
>>>>>>> >>>>>   28  mknod /dev/nbd0p2 b 1 4
>>>>>>> >>>>>
>>>>>>> >>>>> still in /proc/partitions i don't see any info , it shows as
>>>>>>> below
>>>>>>> >>>>>
>>>>>>> >>>>> address@hidden ~]# cat /proc/partitions
>>>>>>> >>>>> major minor  #blocks  name
>>>>>>> >>>>>
>>>>>>> >>>>>   8     0   62914560 sda
>>>>>>> >>>>>   8     1     104391 sda1
>>>>>>> >>>>>   8     2   62806117 sda2
>>>>>>> >>>>> 253     0   56655872 dm-0
>>>>>>> >>>>> 253     1    6127616 dm-1
>>>>>>> >>>>>
>>>>>>> >>>>> address@hidden ~]# fdisk  -l /dev/nbd0
>>>>>>> >>>>>
>>>>>>> >>>>> Disk /dev/nbd0: 21.4 GB, 21474836480 bytes
>>>>>>> >>>>> 255 heads, 63 sectors/track, 2610 cylinders
>>>>>>> >>>>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>>>>>> >>>>>
>>>>>>> >>>>>     Device Boot      Start         End      Blocks   Id  System
>>>>>>> >>>>> /dev/nbd0p1   *           1          13      104391   83  Linux
>>>>>>> >>>>> /dev/nbd0p2              14        2610    20860402+  8e
>>>>>>> Linux LVM
>>>>>>> >>>>>
>>>>>>> >>>>>
>>>>>>> >>>>> when i try for mount , i see below error
>>>>>>> >>>>>
>>>>>>> >>>>>
>>>>>>> >>>>> address@hidden ~]# mount /dev/nbd0p1
>>>>>>> >>>>> /home/test/test.3.5.1b.debug/mnt/boot
>>>>>>> >>>>> mount: you must specify the filesystem type
>>>>>>> >>>>>
>>>>>>> >>>>> i tried to give file system type as below, still issues.
>>>>>>> >>>>>
>>>>>>> >>>>> address@hidden ~]# mount -t ext3 /dev/nbd0p1
>>>>>>> >>>>> /home/test/test.3.5.1b.debug/mnt/boot
>>>>>>> >>>>> mount: wrong fs type, bad option, bad superblock on
>>>>>>> /dev/nbd0p1,
>>>>>>> >>>>>       missing codepage or other error
>>>>>>> >>>>>       In some cases useful info is found in syslog - try
>>>>>>> >>>>>       dmesg | tail  or so
>>>>>>> >>>>>
>>>>>>> >>>>>
>>>>>>> >>>>> Any inputs would be really helpfull..
>>>>>>> >>>>>
>>>>>>> >>>>>
>>>>>>> >>>>> Thanks
>>>>>>> >>>>> Rama Kanth
>>>>>>> >>>>>
>>>>>>> >>>>> On Fri, Nov 30, 2018 at 1:50 PM Pascal <address@hidden>
>>>>>>> wrote:
>>>>>>> >>>>>
>>>>>>> >>>>>> restart from zero if possible...
>>>>>>> >>>>>>
>>>>>>> >>>>>> # qemu-nbd -d /dev/nbd0
>>>>>>> >>>>>> # modprobe -rv nbd
>>>>>>> >>>>>>
>>>>>>> >>>>>> # modprobe nbd
>>>>>>> >>>>>> # qemu-nbd -c /dev/nbd0 /the/file
>>>>>>> >>>>>> # blockdev --rereadpt /dev/nbd0
>>>>>>> >>>>>> # fdisk -l /dev/nbd0
>>>>>>> >>>>>> # mount /dev/nbd0p1 /mount/point
>>>>>>> >>>>>>
>>>>>>> >>>>>> Le jeu. 29 nov. 2018 à 17:32, Jakob Bohm <
>>>>>>> address@hidden> a
>>>>>>> >>>>>> écrit :
>>>>>>> >>>>>>
>>>>>>> >>>>>>> Check
>>>>>>> >>>>>>>
>>>>>>> >>>>>>>    cat /proc/partitions
>>>>>>> >>>>>>>
>>>>>>> >>>>>>> If the partitions are not listed there, the kernel does not
>>>>>>> >>>>>>> recognize them, perhaps the kernel doesn't recognize that
>>>>>>> >>>>>>> nbd0 is a "partitionable disk", and thus does not create the
>>>>>>> >>>>>>> internal nbd0p1 and ndb0p2 devices.
>>>>>>> >>>>>>>
>>>>>>> >>>>>>> If the partitions are listed there, you just need to create
>>>>>>> the
>>>>>>> >>>>>>> actual /dev/nbd0p1 and /dev/nbd0p2 file names with mknod or
>>>>>>> >>>>>>> figure out why your "/dev/" management software (maybe udev,
>>>>>>> >>>>>>> maybe something better) doesn't do that for you.
>>>>>>> >>>>>>>
>>>>>>> >>>>>>> On 29/11/2018 12:46, ramakanth varala wrote:
>>>>>>> >>>>>>>> Still with some errors..
>>>>>>> >>>>>>>>
>>>>>>> >>>>>>>> address@hidden ~]# kpartx -a /dev/nbd0
>>>>>>> >>>>>>>> read error, sector 0
>>>>>>> >>>>>>>> read error, sector 1
>>>>>>> >>>>>>>> read error, sector 29
>>>>>>> >>>>>>>> address@hidden ~]# ls /dev/nbd
>>>>>>> >>>>>>>> nbd0   nbd1   nbd10  nbd11  nbd12  nbd13  nbd14  nbd15  nbd2
>>>>>>> >> nbd3
>>>>>>> >>>>>>> nbd4
>>>>>>> >>>>>>>>  nbd5   nbd6   nbd7   nbd8   nbd9
>>>>>>> >>>>>>>>
>>>>>>> >>>>>>>>
>>>>>>> >>>>>>>>
>>>>>>> >>>>>>>> On Thu, Nov 29, 2018 at 4:22 PM Nerijus Baliūnas <
>>>>>>> >>>>>>>> address@hidden> wrote:
>>>>>>> >>>>>>>>
>>>>>>> >>>>>>>>> Please try kpartx -a /dev/nbd0
>>>>>>> >>>>>>>>>
>>>>>>> >>>>>>>>> 2018-11-29 12:38, ramakanth varala rašė:
>>>>>>> >>>>>>>>>> thanks for the reply ..
>>>>>>> >>>>>>>>>>
>>>>>>> >>>>>>>>>> But i get below error when i do ..
>>>>>>> >>>>>>>>>>
>>>>>>> >>>>>>>>>>
>>>>>>> >>>>>>>>>> address@hidden ~]# partx -a /dev/nbd0
>>>>>>> >>>>>>>>>> HDIO_GETGEO: Inappropriate ioctl for device
>>>>>>> >>>>>>>>>>
>>>>>>> >>>>>>>>>> On Thu, Nov 29, 2018 at 4:04 PM Nerijus Baliūnas <
>>>>>>> >>>>>>>>>> address@hidden> wrote:
>>>>>>> >>>>>>>>>>
>>>>>>> >>>>>>>>>>> 2018-11-29 12:10, ramakanth varala rašė:
>>>>>>> >>>>>>>>>>>> address@hidden ~]# mount /dev/nbd0p1
>>>>>>> >>>>>> /home/test.1.3.debug/mnt/boot
>>>>>>> >>>>>>>>>>>> mount: special device /dev/nbd0p1 does not exist
>>>>>>> >>>>>>>>>>> partx -a /dev/nbd0
>>>>>>> >>>>>>>>>>>
>>>>>>> >>>>>>>
>>>>>>> >>>>>>>
>>>>>>> >>>>>>> Enjoy
>>>>>>> >>>>>>>
>>>>>>> >>>>>>> Jakob
>>>>>>> >>>>>>> --
>>>>>>> >>>>>>> Jakob Bohm, CIO, Partner, WiseMo A/S.
>>>>>>> https://www.wisemo.com
>>>>>>> >>>>>>> Transformervej 29, 2860 Søborg, Denmark.  Direct +45 31 13
>>>>>>> 16 10
>>>>>>> >>>>>>> This public discussion message is non-binding and may contain
>>>>>>> >> errors.
>>>>>>> >>>>>>> WiseMo - Remote Service Management for PCs, Phones and
>>>>>>> Embedded
>>>>>>> >>>>>>>
>>>>>>> >>>>>>>
>>>>>>> >>>>>>>
>>>>>>> >>>>>>
>>>>>>> >>>>>
>>>>>>> >>>>
>>>>>>> >>>
>>>>>>> >>
>>>>>>>
>>>>>>>