[linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[L.M.J]

Hi,

  For the third time, I had to change a failed drive from my home linux RAID5
  box. Previous time went right and this time, I don't know what I did wrong,
  but I broke my RAID5. Well, at least, he won't start.
  /dev/sdb was the failed drive
  /dev/sdc and /dev/sdd are OK.
  
  I tried to reassamble the RAID with this command after I replace sdb and
  create a new partition :
  ~# mdadm -Cv /dev/md0 --assume-clean --level=5
  --raid-devices=3 /dev/sdc1 /dev/sdd1 /dev/sdb1

  Well, I gues I did a mistake here, I should have done this instead :
  ~# mdadm -Cv /dev/md0 --assume-clean --level=5
  --raid-devices=3 /dev/sdc1 /dev/sdd1 missing

  Maybe this wipe out my data...

  Let's go futher, then, pvdisplay, pvscan, vgdisplay returns empty
  information :-(

  Google helped me, and I did this :
  ~# dd if=/dev/md0 bs=512 count=255 skip=1 of=/tmp/md0.txt
   
	[..]
	physical_volumes {
		pv0 {
			id = "5DZit9-6o5V-a1vu-1D1q-fnc0-syEj-kVwAnW"
			device = "/dev/md0"
			status = ["ALLOCATABLE"]
			flags = []
			dev_size = 7814047360
			pe_start = 384
			pe_count = 953863
		}
	}
	logical_volumes {

		lvdata {
			id = "JiwAjc-qkvI-58Ru-RO8n-r63Z-ll3E-SJazO7"
			status = ["READ", "WRITE", "VISIBLE"]
			flags = []
			segment_count = 1
	[..]



  Since I saw lvm information, I guess I haven't lost all information yet...

  I tried an unhoped command :
  ~# pvcreate --uuid "5DZit9-6o5V-a1vu-1D1q-fnc0-syEj-kVwAnW" --restorefile /etc/lvm/archive/lvm-raid_00302.vg /dev/md0

  Then,
  ~# vgcfgrestore lvm-raid

  ~# lvs -a -o +devices
  LV     VG       Attr   LSize   Origin Snap%  Move Log Copy%  Convert  Devices 
  lvdata lvm-raid -wi-a- 450,00g                                       /dev/md0(148480)
  lvmp   lvm-raid -wi-a-  80,00g                                       /dev/md0(263680)

  Then :
  ~# lvchange -ay /dev/lvm-raid/lv*

  I was quite happy until now.
  Problem appears now when I try to mount those 2 LV (lvdata & lvmp) as ext4 partition :
  ~# mount /home/foo/RAID_mp/

  ~# mount | grep -i mp
     /dev/mapper/lvm--raid-lvmp on /home/foo/RAID_mp type ext4 (rw)

  ~# df -h /home/foo/RAID_mp
     Filesystem                  Size  Used Avail Use% Mounted on
     /dev/mapper/lvm--raid-lvmp   79G   61G   19G  77% /home/foo/RAID_mp


  Here is the big problem 
  ~# ls -la /home/foo/RAID_mp
     total 0

  Worst on the other LVM :
  ~# mount /home/foo/RAID_data 
     mount: wrong fs type, bad option, bad superblock on /dev/mapper/lvm--raid-lvdata,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so


  I bet I recover the LVM structure but the data are wiped out, don't you think ?

  ~# fsck -n -v /dev/mapper/lvm--raid-lvdata
     fsck from util-linux-ng 2.17.2
     e2fsck 1.41.11 (14-Mar-2010)
     fsck.ext4: Group descriptors look bad... trying backup blocks...
     fsck.ext4: Bad magic number in super-block when using the backup blocks
     fsck.ext4: going back to original superblock
     fsck.ext4: Device or resource busy while trying to open /dev/mapper/lvm--raid-lvdata
     Filesystem mounted or opened exclusively by another program?


   
  Any help is welcome if you have any idea how to rescue me pleassse !

 

  
 
-- 
 LMJ
 "May the source be with you my young padawan"

Re: [linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[Stuart Gathman]

On 04/17/2014 06:22 AM, L.M.J wrote:
>    For the third time, I had to change a failed drive from my home linux RAID5
>    box. Previous time went right and this time, I don't know what I did wrong,
>    but I broke my RAID5. Well, at least, he won't start.
>    /dev/sdb was the failed drive
>    /dev/sdc and /dev/sdd are OK.
>    
>    I tried to reassamble the RAID with this command after I replace sdb and
>    create a new partition :
>    ~# mdadm -Cv /dev/md0 --assume-clean --level=5
>    --raid-devices=3 /dev/sdc1 /dev/sdd1 /dev/sdb1
>
>    Well, I gues I did a mistake here, I should have done this instead :
>    ~# mdadm -Cv /dev/md0 --assume-clean --level=5
>    --raid-devices=3 /dev/sdc1 /dev/sdd1 missing
>
>    Maybe this wipe out my data...
This is not an LVM problem, but an mdadm usage problem.

You told mdadm to create a new empty md device!  (-C means create a new 
array!)  You should have just started the old degraded md array, remove 
the failed drive, and add the new drive.

But I don't think your data is gone yet... (because of assume-clean).
>    Let's go futher, then, pvdisplay, pvscan, vgdisplay returns empty
>    information :-(
>
>    Google helped me, and I did this :
>    ~# dd if=/dev/md0 bs=512 count=255 skip=1 of=/tmp/md0.txt
>     
> 	[..]
> 	physical_volumes {
> 		pv0 {
> 			id = "5DZit9-6o5V-a1vu-1D1q-fnc0-syEj-kVwAnW"
> 			device = "/dev/md0"
> 			status = ["ALLOCATABLE"]
> 			flags = []
> 			dev_size = 7814047360
> 			pe_start = 384
> 			pe_count = 953863
> 		}
> 	}
> 	logical_volumes {
>
> 		lvdata {
> 			id = "JiwAjc-qkvI-58Ru-RO8n-r63Z-ll3E-SJazO7"
> 			status = ["READ", "WRITE", "VISIBLE"]
> 			flags = []
> 			segment_count = 1
> 	[..]
>
>
>
>    Since I saw lvm information, I guess I haven't lost all information yet...
nothing is lost ... yet

What you needed to do was REMOVE the blank drive before you write 
anything to the RAID5!  You didn't add it as a missing drive to be restored,
as you noted.
>    I tried an unhoped command :
>    ~# pvcreate --uuid "5DZit9-6o5V-a1vu-1D1q-fnc0-syEj-kVwAnW" --restorefile /etc/lvm/archive/lvm-raid_00302.vg /dev/md0

*Now* you are writing to the md and destroying your data!
>    Then,
>    ~# vgcfgrestore lvm-raid
Overwriting your LVM metadata.  But maybe not the end of the world YET...
>    ~# lvs -a -o +devices
>    LV     VG       Attr   LSize   Origin Snap%  Move Log Copy%  Convert  Devices
>    lvdata lvm-raid -wi-a- 450,00g                                       /dev/md0(148480)
>    lvmp   lvm-raid -wi-a-  80,00g                                       /dev/md0(263680)
>
>    Then :
>    ~# lvchange -ay /dev/lvm-raid/lv*
>
>    I was quite happy until now.
>    Problem appears now when I try to mount those 2 LV (lvdata & lvmp) as ext4 partition :
>    ~# mount /home/foo/RAID_mp/
>
>    ~# mount | grep -i mp
>       /dev/mapper/lvm--raid-lvmp on /home/foo/RAID_mp type ext4 (rw)
>
>    ~# df -h /home/foo/RAID_mp
>       Filesystem                  Size  Used Avail Use% Mounted on
>       /dev/mapper/lvm--raid-lvmp   79G   61G   19G  77% /home/foo/RAID_mp
>
>
>    Here is the big problem
>    ~# ls -la /home/foo/RAID_mp
>       total 0
>
>    Worst on the other LVM :
>    ~# mount /home/foo/RAID_data
>       mount: wrong fs type, bad option, bad superblock on /dev/mapper/lvm--raid-lvdata,
>         missing codepage or helper program, or other error
>         In some cases useful info is found in syslog - try
>         dmesg | tail  or so
Yes, you told md that the drive with random/blank data was good data!  
If ONLY you had mounted those filesystems
READ ONLY while checking things out, you would still be ok.  But now, 
you have overwritten stuff!

>    I bet I recover the LVM structure but the data are wiped out, don't you think ?
>
>    ~# fsck -n -v /dev/mapper/lvm--raid-lvdata
>       fsck from util-linux-ng 2.17.2
>       e2fsck 1.41.11 (14-Mar-2010)
>       fsck.ext4: Group descriptors look bad... trying backup blocks...
>       fsck.ext4: Bad magic number in super-block when using the backup blocks
>       fsck.ext4: going back to original superblock
>       fsck.ext4: Device or resource busy while trying to open /dev/mapper/lvm--raid-lvdata
>       Filesystem mounted or opened exclusively by another program?
>
>
>     
>    Any help is welcome if you have any idea how to rescue me pleassse !
Fortunately, your fsck was read only.  At this point, you need to 
crash/halt your system with no shutdown (to avoid further writes to the 
mounted filesystems).
Then REMOVE the new drive.  Start up again, and add the new drive properly.

You should check stuff out READ ONLY.  You will need fsck (READ ONLY at 
first), and at least some data has been destroyed.
If the data is really important, you need to copy the two old drives 
somewhere before you do ANYTHING else.  Buy two more drives!  That will 
let you recover from any more mistakes typing Create instead of Assemble 
or Manage.  (Note that --assume-clean warns you that you really need to 
know what you are doing!)

Re: [linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[L.M.J]

Le Thu, 17 Apr 2014 15:33:48 -0400,
Stuart Gathman <stuart@gathman.org> a �crit :

Thanks for your answer

> Fortunately, your fsck was read only.  At this point, you need to 
> crash/halt your system with no shutdown (to avoid further writes to the 
> mounted filesystems).
> Then REMOVE the new drive.  Start up again, and add the new drive properly.

RAID5 recreate : started with 2 original drives

~# mdadm --assemble --force /dev/md0 /dev/sdc1 /dev/sdd1

md0 status is normal, missing new drive : sdb(1)
~# cat /proc/mdstat 
md0 : active raid5 sdc1[0] sdd1[1]
      3907023872 blocks level 5, 64k chunk, algorithm 2 [3/2] [UU_]


> You should check stuff out READ ONLY.  You will need fsck (READ ONLY at 
> first), and at least some data has been destroyed.
> If the data is really important, you need to copy the two old drives 
> somewhere before you do ANYTHING else.  Buy two more drives!  That will 
> let you recover from any more mistakes typing Create instead of Assemble 
> or Manage.  (Note that --assume-clean warns you that you really need to 
> know what you are doing!)

I try a read-only fsck

~# fsck -n -v -f /dev/lvm-raid/lvmp3 
fsck from util-linux-ng 2.17.2
e2fsck 1.41.11 (14-Mar-2010)
Resize inode not valid.  Recreate? no
Pass 1: Checking inodes, blocks, and sizes
Inode 7, i_blocks is 114136, should be 8.  Fix? no
Inode 786433 is in use, but has dtime set.  Fix? no
Inode 786433 has imagic flag set.  Clear? no
Inode 786433 has compression flag set on filesystem without compression
support.  Clear? no Inode 786433 has INDEX_FL flag set but is not a directory.
Clear HTree index? no
HTREE directory inode 786433 has an invalid root node.
Clear HTree index? no
Inode 786433, i_blocks is 4294967295, should be 0.  Fix? no
[...]
Directory entry for '.' in ... (11) is big.
Split? no
Missing '.' in directory inode 262145.
Fix? no
Invalid inode number for '.' in directory inode 262145.
Fix? no
Directory entry for '.' in ... (262145) is big.
Split? no
Directory inode 917506, block #0, offset 0: directory corrupted
Salvage? no
e2fsck: aborted


Sounds bad, what should I do know ?

Re: [linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[L.M.J]

What do you think about this command :


  ~# dd if=/dev/md0 bs=512 count=255 skip=1 of=/tmp/md0.txt
   
	[..]
	physical_volumes {
		pv0 {
			id = "5DZit9-6o5V-a1vu-1D1q-fnc0-syEj-kVwAnW"
			device = "/dev/md0"
			status = ["ALLOCATABLE"]
			flags = []
			dev_size = 7814047360
			pe_start = 384
			pe_count = 953863
		}
	}
	logical_volumes {

		lvdata {
			id = "JiwAjc-qkvI-58Ru-RO8n-r63Z-ll3E-SJazO7"
			status = ["READ", "WRITE", "VISIBLE"]
			flags = []
			segment_count = 1
	[..]

I presume I still have data on my broken RAID5.

I did a pvcreate --restorefile and vgcfgrestore.
I can see now my 2 LVM, but my EXT4 filesystem are empty, df reports some realist disk usage, fsck (Read
only) find tons of errors.

Is there a way to recover my data on the EXT4 FS ?




Le Fri, 18 Apr 2014 23:14:17 +0200,
"L.M.J" <linuxmasterjedi@free.fr> a �crit :

> Le Thu, 17 Apr 2014 15:33:48 -0400,
> Stuart Gathman <stuart@gathman.org> a �crit :
> 
> Thanks for your answer
> 
> > Fortunately, your fsck was read only.  At this point, you need to 
> > crash/halt your system with no shutdown (to avoid further writes to the 
> > mounted filesystems).
> > Then REMOVE the new drive.  Start up again, and add the new drive properly.
> 
> RAID5 recreate : started with 2 original drives
> 
> ~# mdadm --assemble --force /dev/md0 /dev/sdc1 /dev/sdd1
> 
> md0 status is normal, missing new drive : sdb(1)
> ~# cat /proc/mdstat 
> md0 : active raid5 sdc1[0] sdd1[1]
>       3907023872 blocks level 5, 64k chunk, algorithm 2 [3/2] [UU_]
> 
> 
> > You should check stuff out READ ONLY.  You will need fsck (READ ONLY at 
> > first), and at least some data has been destroyed.
> > If the data is really important, you need to copy the two old drives 
> > somewhere before you do ANYTHING else.  Buy two more drives!  That will 
> > let you recover from any more mistakes typing Create instead of Assemble 
> > or Manage.  (Note that --assume-clean warns you that you really need to 
> > know what you are doing!)
> 
> I try a read-only fsck
> 
> ~# fsck -n -v -f /dev/lvm-raid/lvmp3 
> fsck from util-linux-ng 2.17.2
> e2fsck 1.41.11 (14-Mar-2010)
> Resize inode not valid.  Recreate? no
> Pass 1: Checking inodes, blocks, and sizes
> Inode 7, i_blocks is 114136, should be 8.  Fix? no
> Inode 786433 is in use, but has dtime set.  Fix? no
> Inode 786433 has imagic flag set.  Clear? no
> Inode 786433 has compression flag set on filesystem without compression
> support.  Clear? no Inode 786433 has INDEX_FL flag set but is not a directory.
> Clear HTree index? no
> HTREE directory inode 786433 has an invalid root node.
> Clear HTree index? no
> Inode 786433, i_blocks is 4294967295, should be 0.  Fix? no
> [...]
> Directory entry for '.' in ... (11) is big.
> Split? no
> Missing '.' in directory inode 262145.
> Fix? no
> Invalid inode number for '.' in directory inode 262145.
> Fix? no
> Directory entry for '.' in ... (262145) is big.
> Split? no
> Directory inode 917506, block #0, offset 0: directory corrupted
> Salvage? no
> e2fsck: aborted
> 
> 
> Sounds bad, what should I do know ?
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[L. M. J]

On 26 avril 2014 20:47:44 CEST, "L.M.J" <linuxmasterjedi@free.fr> wrote:
>
>What do you think about this command :
>
>
>  ~# dd if=/dev/md0 bs=512 count=255 skip=1 of=/tmp/md0.txt
>   
>	[..]
>	physical_volumes {
>		pv0 {
>			id = "5DZit9-6o5V-a1vu-1D1q-fnc0-syEj-kVwAnW"
>			device = "/dev/md0"
>			status = ["ALLOCATABLE"]
>			flags = []
>			dev_size = 7814047360
>			pe_start = 384
>			pe_count = 953863
>		}
>	}
>	logical_volumes {
>
>		lvdata {
>			id = "JiwAjc-qkvI-58Ru-RO8n-r63Z-ll3E-SJazO7"
>			status = ["READ", "WRITE", "VISIBLE"]
>			flags = []
>			segment_count = 1
>	[..]
>
>I presume I still have data on my broken RAID5.
>
>I did a pvcreate --restorefile and vgcfgrestore.
>I can see now my 2 LVM, but my EXT4 filesystem are empty, df reports
>some realist disk usage, fsck (Read
>only) find tons of errors.
>
>Is there a way to recover my data on the EXT4 FS ?
>
>
>
>
>Le Fri, 18 Apr 2014 23:14:17 +0200,
>"L.M.J" <linuxmasterjedi@free.fr> a écrit :
>
>> Le Thu, 17 Apr 2014 15:33:48 -0400,
>> Stuart Gathman <stuart@gathman.org> a écrit :
>> 
>> Thanks for your answer
>> 
>> > Fortunately, your fsck was read only.  At this point, you need to 
>> > crash/halt your system with no shutdown (to avoid further writes to
>the 
>> > mounted filesystems).
>> > Then REMOVE the new drive.  Start up again, and add the new drive
>properly.
>> 
>> RAID5 recreate : started with 2 original drives
>> 
>> ~# mdadm --assemble --force /dev/md0 /dev/sdc1 /dev/sdd1
>> 
>> md0 status is normal, missing new drive : sdb(1)
>> ~# cat /proc/mdstat 
>> md0 : active raid5 sdc1[0] sdd1[1]
>>       3907023872 blocks level 5, 64k chunk, algorithm 2 [3/2] [UU_]
>> 
>> 
>> > You should check stuff out READ ONLY.  You will need fsck (READ
>ONLY at 
>> > first), and at least some data has been destroyed.
>> > If the data is really important, you need to copy the two old
>drives 
>> > somewhere before you do ANYTHING else.  Buy two more drives!  That
>will 
>> > let you recover from any more mistakes typing Create instead of
>Assemble 
>> > or Manage.  (Note that --assume-clean warns you that you really
>need to 
>> > know what you are doing!)
>> 
>> I try a read-only fsck
>> 
>> ~# fsck -n -v -f /dev/lvm-raid/lvmp3 
>> fsck from util-linux-ng 2.17.2
>> e2fsck 1.41.11 (14-Mar-2010)
>> Resize inode not valid.  Recreate? no
>> Pass 1: Checking inodes, blocks, and sizes
>> Inode 7, i_blocks is 114136, should be 8.  Fix? no
>> Inode 786433 is in use, but has dtime set.  Fix? no
>> Inode 786433 has imagic flag set.  Clear? no
>> Inode 786433 has compression flag set on filesystem without
>compression
>> support.  Clear? no Inode 786433 has INDEX_FL flag set but is not a
>directory.
>> Clear HTree index? no
>> HTREE directory inode 786433 has an invalid root node.
>> Clear HTree index? no
>> Inode 786433, i_blocks is 4294967295, should be 0.  Fix? no
>> [...]
>> Directory entry for '.' in ... (11) is big.
>> Split? no
>> Missing '.' in directory inode 262145.
>> Fix? no
>> Invalid inode number for '.' in directory inode 262145.
>> Fix? no
>> Directory entry for '.' in ... (262145) is big.
>> Split? no
>> Directory inode 917506, block #0, offset 0: directory corrupted
>> Salvage? no
>> e2fsck: aborted
>> 
>> 
>> Sounds bad, what should I do know ?
>> 
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
>_______________________________________________
>linux-lvm mailing list
>linux-lvm@redhat.com
>https://www.redhat.com/mailman/listinfo/linux-lvm
>read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Help please :-( 
-- 
May the open source be with you my young padawan. 

Envoyé de mon téléphone, excusez la brièveté.

Re: [linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[Stuart Gathman]

Long ago, Nostradamus foresaw that on 04/26/2014 02:47 PM, L.M.J would
write:
>
> I presume I still have data on my broken RAID5.
>
> I did a pvcreate --restorefile and vgcfgrestore.
Did you restore the raid 5, taking out the new drive, and add00ing it
back in properly?  I can't take the time right now to give you a step by
step.  The big warning on what you did wasn't a joke.  You should get
help from md driver people.  You do not have an LVM problem.

> I can see now my 2 LVM, but my EXT4 filesystem are empty, df reports
some realist disk usage, fsck (Read only) find ? tons of errors. Is
there a way to recover my data on the EXT4 FS ? Le Fri, 18 Apr 2014
23:14:17 +0200, "L.M.J"

None of that is relevant until you restore your raid 5.  Your problem
was that you told md that your new blank drive was good, in-sync data. 
Which is obviously isn't.  You need to degrade your raid back to the one
missing drive.  Then add the new drive normally - NOT using that experts
only shortcut with the big warning, which you used incorrectly.

Re: [linux-lvm] LVM issues after replacing linux mdadm RAID5 drive

[L.M.J]

Le Fri, 02 May 2014 00:02:25 -0400,
Stuart Gathman <stuart@gathman.org> a �crit :

> > I presume I still have data on my broken RAID5.
> >
> > I did a pvcreate --restorefile and vgcfgrestore.  
> Did you restore the raid 5, taking out the new drive, and add00ing it
> back in properly?  I can't take the time right now to give you a step by
> step.  The big warning on what you did wasn't a joke.  You should get
> help from md driver people.  You do not have an LVM problem.

Yes, I did that, I had it back properly, but I guess the problem comes from the first sync, which was bad...