02-29-2008
How to corrupt a superblock?
The mounted device is a loopback one using lofiadm. Can dd command be used to get this condition?
Need help urgently.
Thanks in advance.
10 More Discussions You Might Find Interesting
1. Linux
Hi everyone,
OK, I've made a monumental fsck-up of my linux installation AND I did not backup my data properly (idiot!), so I'm really up the proverbial without a paddle here.
Basically the problem is I re-sized my /home partition (hda13) using Partition Magic 8.0, after doing so my mandrake... (0 Replies)
Discussion started by: alarmcall
0 Replies
2. AIX
Dear All
Last day in Aix 5.2 server by executing
# df –g
I found following:
Filesystem GB blocks Free %Used Iused %Iused Mounted on
.
.
/dev/fslv00 58.00 136.70 -135% 212103 1% /sprod
After shutting down by following command
# shutdown –h
And when... (1 Reply)
Discussion started by: xa52000
1 Replies
3. UNIX for Advanced & Expert Users
Is there a way to recover or rebuild the superblock of an ext3 filesystem with out loosing data?
Thanks (5 Replies)
Discussion started by: lochraven
5 Replies
4. Red Hat
can anybody help me to recovermy superblock , the recent power crash has done some stuff on my linux redhat 9 box .
when i startup the machine iam getting the following error:
The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it... (2 Replies)
Discussion started by: ppass
2 Replies
5. HP-UX
Hallo Friends,
I have application X running on hpux 11.11 and oracle 9i release 2. I recently had a hardware failure on disk /dev/dsk/c2t0d0
Below is the systemlog file :
root@a7dmc:/var/adm/syslog > /opt/resmon/bin/resdata -R 155713541 -r /storage/events/enclosures/gazemon/0_1_1_0.0.0... (11 Replies)
Discussion started by: kekanap
11 Replies
6. Linux
Hi Guys,
I really don't know where to put my query about this. And as a newbie, I think CentOS is closest to Ubuntu. Anyway, here's my dilemma. I have installed a VMWare - ESX 3.5 and installed CentOS 6 and cloned the CentOS 6. The first CentOS was working fine, when i cloned it, and the cloning... (2 Replies)
Discussion started by: init6_
2 Replies
7. UNIX for Advanced & Expert Users
Good morning!
I met a problem on a FS with AIX 5.3
It's not possible to mount the FS because of a dirty superblock.
I tried few things without success. I need your help to solve my problem guys. Do you have any idea please?
Thanks a lot
drp01,/home/root # mount /GSPRES/data
Replaying... (9 Replies)
Discussion started by: Castelior
9 Replies
8. Linux
I have a failed 160 GB Western Digital Netcenter NAS disk and its image after failing in .DSK format.
When I connect the disk to my ubuntu machine and typed:
# losetup -o 512006144 /dev/loop1 /dev/sdc
# mkdir /tmp/sdc
# mount -r -t reiserfs /dev/loop1 /tmp/sdc
I get my folders and... (0 Replies)
Discussion started by: jalil1408
0 Replies
9. Solaris
Hi All,
we are having a file system error in one of our servers. The server failed to boot in usual user mode. Instead boot with single user mode and requesting to run a FSCK manually to repair the corrupted. see the below output.
Netra T2000, No Keyboard
Copyright 2008 Sun Microsystems,... (5 Replies)
Discussion started by: Buddhike G
5 Replies
10. Red Hat
Hi Friends . my linux try to start very slowly after give it this error:
mount: wrong fs type, bad option, bad superblock on /dev/mapper/VolGroup-lv_root,
missing codepage or helper program, or other error
in some cases useful info is found in syslog - try
dmesg : tail or so
Kernel panic... (3 Replies)
Discussion started by: blackjuan
3 Replies
lofs(7FS) File Systems lofs(7FS)
NAME
lofs - loopback virtual file system
SYNOPSIS
#include <sys/param.h>
#include <sys/mount.h>
int mount (const char* dir, const char* virtual, int mflag, lofs, NULL, 0);
DESCRIPTION
The loopback file system device allows new, virtual file systems to be created, which provide access to existing files using alternate
pathnames. Once the virtual file system is created, other file systems can be mounted within it, without affecting the original file sys-
tem. However, file systems which are subsequently mounted onto the original file system are visible to the virtual file system, unless or
until the corresponding mount point in the virtual file system is covered by a file system mounted there.
virtual is the mount point for the virtual file system. dir is the pathname of the existing file system. mflag specifies the mount options;
the MS_DATA bit in mflag must be set. If the MS_RDONLY bit in mflag is not set, accesses to the loop back file system are the same as
for the underlying file system. Otherwise, all accesses in the loopback file system will be read-only. All other mount(2) options are
inherited from the underlying file systems.
A loopback mount of '/' onto /tmp/newroot allows the entire file system hierarchy to appear as if it were duplicated under /tmp/newroot,
including any file systems mounted from remote NFS servers. All files would then be accessible either from a pathname relative to '/' or
from a pathname relative to /tmp/newroot until such time as a file system is mounted in /tmp/newroot, or any of its subdirectories.
Loopback mounts of '/' can be performed in conjunction with the chroot(2) system call, to provide a complete virtual file system to a
process or family of processes.
Recursive traversal of loopback mount points is not allowed. After the loopback mount of /tmp/newroot, the file /tmp/newroot/tmp/newroot
does not contain yet another file system hierarchy; rather, it appears just as /tmp/newroot did before the loopback mount was performed
(for example, as an empty directory).
Examples
lofs file systems are mounted using:
mount -F lofs /tmp /mnt
SEE ALSO
lofiadm(1M), mount(1M), chroot(2), mount(2), sysfs(2), vfstab(4), lofi(7D)
WARNINGS
Loopback mounts must be used with care; the potential for confusing users and applications is enormous. A loopback mount entry in
/etc/vfstab must be placed after the mount points of both directories it depends on. This is most easily accomplished by making the loop-
back mount entry the last in /etc/vfstab.
SunOS 5.10 10 Apr 2001 lofs(7FS)