Cannot mount sdb : Wish to rsync the 2 sata drives

vaibhavs · 10-22-2009, 04:19 AM

Hi,

I have CentOS 5.3 (Final)

2 SATA disks attached on boot

Code:

[root@server1 ~]# fdisk -l

Disk /dev/sda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14       30401   244091610   8e  Linux LVM

Disk /dev/sdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          13      104391   83  Linux
/dev/sdb2              14       30401   244091610   8e  Linux LVM

Did this:
mkdir /mnt/HDD2
mount /dev/sdb /mnt/HDD2 -rw

Got this response "mount: /dev/sdb already mounted or /mnt/HDD2 busy"

I have been reading on the net; multiple causes and resolutions but all dated 2004-2005. Tried some, no help.

I want to mount the 2nd sata disk, rsync my sda to sdb, then unmount sdb

Someone pls help me...

Thx
Vai

avijitp · 10-22-2009, 04:25 AM

Do a df -h and see if the /dev/sdb1 or /dev/sdb2 is already mounted to some other mount points.

vaibhavs · 10-22-2009, 04:27 AM

Not mounted.

Quote:

[root@server1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
224G 3.7G 209G 2% /
/dev/sda1 99M 19M 75M 20% /boot
tmpfs 1013M 0 1013M 0% /dev/shm
[root@server1 ~]#

avijitp · 10-22-2009, 04:33 AM

Is this a new drive that you attached recently. It seems that /dev/sdb2 is part of the LVM volume group VolGroup00.

What are the output of the following commands:
vgdisplay -vv
pvdisplay -v

vaibhavs · 10-22-2009, 04:42 AM

Code:

[root@server1 ~]# vgdisplay -vv
      Setting global/locking_type to 1
      File-based locking selected.
      Setting global/locking_dir to /var/lock/lvm
    Finding all volume groups
      /dev/root: No label detected
      /dev/sda1: No label detected
      /dev/VolGroup00/LogVol01: No label detected
      /dev/sda2: lvm2 label detected
      Locking /var/lock/lvm/V_VolGroup00 RB
    Finding volume group "VolGroup00"
      /dev/sda2: lvm2 label detected
  --- Volume group ---
  VG Name               VolGroup00
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               232.78 GB
  PE Size               32.00 MB
  Total PE              7449
  Alloc PE / Size       7449 / 232.78 GB
  Free  PE / Size       0 / 0
  VG UUID               rYEsOa-Bmao-0NKS-Jhgg-fnvu-1fXn-4DFVig

  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol00
  VG Name                VolGroup00
  LV UUID                jVqFmo-Uj3A-YxIV-HJMc-LgL5-tItD-WK61Db
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                230.84 GB
  Current LE             7387
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol01
  VG Name                VolGroup00
  LV UUID                nfWROu-7SCT-qqVE-ph2P-teGh-u0YU-SXYu87
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.94 GB
  Current LE             62
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1

  --- Physical volumes ---
  PV Name               /dev/sda2
  PV UUID               Ytx80v-bcMA-DdGW-a3Me-REY2-4U4X-fuJd5v
  PV Status             allocatable
  Total PE / Free PE    7449 / 0

      Unlocking /var/lock/lvm/V_VolGroup00

Code:

[root@server1 ~]# pvdisplay -v
    Scanning for physical volume names
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               VolGroup00
  PV Size               232.78 GB / not usable 2.71 MB
  Allocatable           yes (but full)
  PE Size (KByte)       32768
  Total PE              7449
  Free PE               0
  Allocated PE          7449
  PV UUID               Ytx80v-bcMA-DdGW-a3Me-REY2-4U4X-fuJd5v

avijitp · 10-22-2009, 04:45 AM

It is not part of the LVM then.

Try this and see how it goes:

mount /dev/sdb2 /mnt/HDD2

vaibhavs · 10-22-2009, 04:52 AM

Code:

[root@server1 ~]# mount /dev/sdb2 /mnt/HDD2
mount: /dev/sdb2 already mounted or /mnt/HDD2 busy
[root@server1 ~]#

avijitp · 10-22-2009, 04:59 AM

What is your pwd? Are you in the /mnt/HDD2 directory?

whats output of :
pwd
ls -l /mnt/HDD2

vaibhavs · 10-22-2009, 05:02 AM

Code:

[root@server1 ~]# pwd
/root
[root@server1 ~]# ls -l /mnt/HDD2
total 0
[root@server1 ~]#

avijitp · 10-22-2009, 05:08 AM

/dev/sdb already has an LVM lebel. Was this done by you after recently attaching the drive or this drive was being used in some other server under LVM control?

vaibhavs · 10-22-2009, 05:23 AM

It was a blank - brand new hdd.

I mirrored the existing disc on the new disc using "DISC COPY 2" -- its a sector-by-sector disc copy tool.

Now I want to simply do rsync on `alternate day` basis to copy just the changes on sdb

I hope this is making sense and I can achieve this...

Thx for all your help.

Vai

avijitp · 10-22-2009, 05:54 AM

Ah..as you have done a sector by sector copy, it has copied the LVM level as well, which is making this disk as another disk under LVM control. I believe this is why you are getting a error as kernel also sees that under a LVM and not allowing to mount it seperately.

I might be wrong. However, I will expect others to comment on this so that we both have a better idea to achieve this.

vaibhavs · 10-22-2009, 07:09 AM

I really appreciate your help and hope someone can get me out of this....

On second thoughts, what if I did a new install of CentOS.
Would I still have faced this LVM problem ?

Since we are on this subject, any idea what is the best way (commands) to do a full HDD rsync
I am thinking of the following process:
- Stop mysqld, httpd
- Mount HDD2
- RSync
- unmount HDD2
- start mysql, httpd

Let me know if this is good!

Thx
Vai

avijitp · 10-22-2009, 09:35 AM

A clean install would have been good with same file system layout as the current one.

Quote:

I am thinking of the following process:
- Stop mysqld, httpd
- Mount HDD2
- RSync
- unmount HDD2
- start mysql, httpd

Let me know if this is good!

Sounds good to me.

vaibhavs · 10-23-2009, 07:00 AM

Update:

I installed the basic OS (centOS 5.3) on the Backup HDD and again connected it to the main server.

This time when I execute the mount command, I get the following response.

Code:

[root@server1 ~]# fdisk -l

Disk /dev/sda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14       30401   244091610   8e  Linux LVM

Disk /dev/sdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          13      104391   83  Linux
/dev/sdb2              14       30401   244091610   8e  Linux LVM

[root@server1 ~]#

Code:

[root@server1 ~]# mount -t ext3 -o rw /dev/sdb /mnt/HDD2
mount: wrong fs type, bad option, bad superblock on /dev/sdb,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

[root@server1 ~]#

Someone pls help me, this issue is driving me nuts!!

Thx
Vai