<div>If global bitmap is gone. then the fs is unusable. But you can extract data using</div><div>the rdump command in debugfs.ocfs. The success depends on how much of the</div><div>device is still usable.</div><div class="gmail_extra">
<br><br><div class="gmail_quote">On Fri, Nov 9, 2012 at 5:50 PM, Marian Serban <span dir="ltr"><<a href="mailto:marian@easic.ro" target="_blank">marian@easic.ro</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>I tried hacking the fsck.ocfs2 source
code by not considering metaecc flag. Then I ran into <br>
<br>
<tt>journal recovery: Bad magic number in inode while looking up
the journal inode for slot 0</tt><div class="im"><tt><br>
</tt><tt>fsck encountered unrecoverable errors while replaying the
journals and will not continue</tt><tt><br>
</tt><br></div>
After bypassing journal replay function, I got <br>
<br>
<tt>Pass 0a: Checking cluster allocation chains</tt><tt><br>
</tt><tt>pass0: Bad magic number in inode while looking up the
global bitmap inode</tt><tt><br>
</tt><tt>fsck.ocfs2: Bad magic number in inode while performing
pass 0</tt><tt><br>
</tt><br>
<br>
Does it mean the filesystem is destroyed completely?<div><div class="h5"><br>
<br>
<br>
<br>
On 10.11.2012 02:54, Marian Serban wrote:<br>
</div></div></div><div><div class="h5">
<blockquote type="cite">
<div>That's the kernel:<br>
<br>
<tt>Linux <a href="http://ro02xsrv003.bv.easic.ro" target="_blank">ro02xsrv003.bv.easic.ro</a> 2.6.39.4 #6 SMP Mon Dec 12
12:09:49 EET 2011 x86_64 x86_64 x86_64 GNU/Linux</tt><tt><br>
</tt><br>
Anyway, I tried disabling the metaecc feature, no luck.<br>
<br>
<tt>[root@ro02xsrv003 ~]# tunefs.ocfs2 --fs-features=nometaecc
/dev/mapper/volgr1-lvol0</tt><tt><br>
</tt><tt>tunefs.ocfs2: I/O error on channel while opening device
"/dev/mapper/volgr1-lvol0"</tt><tt><br>
</tt><br>
These are the last lines of strace corresponding to the
tunefs.ocfs command:<br>
<tt><br>
<br>
<br>
open("/sys/fs/ocfs2/cluster_stack", O_RDONLY) = 4<br>
fstat(4, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0<br>
mmap(NULL, 4096, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f54aad05000<br>
read(4, "o2cb\n", 4096) = 5<br>
close(4) = 0<br>
munmap(0x7f54aad05000, 4096) = 0<br>
open("/sys/fs/o2cb/interface_revision", O_RDONLY) = 4<br>
read(4, "5\n", 15) = 2<br>
read(4, "", 13) = 0<br>
close(4) = 0<br>
</tt><tt>stat("/sys/kernel/config", {st_mode=S_IFDIR|0755,
st_size=0, ...}) = 0</tt><tt><br>
</tt><tt>statfs("/sys/kernel/config", {f_type=0x62656570,
f_bsize=4096, f_blocks=0, f_bfree=0, f_bavail=0, f_files=0,
f_ffree=0, f_fsid={0, 0}, f_namelen=255, f_frsize=4096}) = 0</tt><tt><br>
</tt><tt>open("/dev/mapper/volgr1-lvol0", O_RDONLY) = 4</tt><tt><br>
</tt><tt>ioctl(4, BLKSSZGET, 0x7fffce711454) = 0</tt><tt><br>
</tt><tt>close(4) = 0</tt><tt><br>
</tt><tt>pread(3,
"\0\0\v\25\37\1\200\200\202@\21\2\30\26\0\0\0,\17\272\241\4\340\210\311\377\17\300\327\332\373\17"...,
4096, 532480) = 4096</tt><tt><br>
</tt><tt>close(3) = 0</tt><tt><br>
</tt><tt>write(2, "tunefs.ocfs2", 12tunefs.ocfs2) =
12</tt><tt><br>
</tt><tt>write(2, ": ", 2: ) = 2</tt><tt><br>
</tt><tt>write(2, "I/O error on channel", 20I/O error on
channel) = 20</tt><tt><br>
</tt><tt>write(2, " ", 1 ) = 1</tt><tt><br>
</tt><tt>write(2, "while opening device \"/dev/mappe"...,
47while opening device "/dev/mapper/volgr1-lvol0") = 47</tt><tt><br>
</tt><tt>write(2, "\r\n", 2</tt><tt><br>
</tt><br>
<br>
<br>
<br>
<br>
On 10.11.2012 02:06, Sunil Mushran wrote:<br>
</div>
<blockquote type="cite">It's either that or a check sum problem. Disable
metaecc. Not sure which kernel you are running.
<div>We had fixed few problems few years ago around this. If
your kernel is older, then it could be</div>
<div>a known issue.</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Fri, Nov 9, 2012 at 12:50 PM,
Marian Serban <span dir="ltr"><<a href="mailto:marian@easic.ro" target="_blank">marian@easic.ro</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi
Sunil,<br>
<br>
Thank you for answering. Unfortunately, it doesn't seem
like it's a hardware problem. There's no way a cable can
be loose because it's iSCSI over 1G Ethernet (copper
wires) environment. Also I performed "dd if=/dev/....
of=/dev/null" and first 16GB or so are fine. "Dmesg" shows
no errors.<br>
<br>
<br>
Also tried with debugfs.ocfs2:<br>
<br>
<br>
[root@ro02xsrv003 ~]# debugfs.ocfs2
/dev/mapper/volgr1-lvol0<br>
debugfs.ocfs2 1.6.3<br>
debugfs: ls<br>
ls: Bad magic number in inode '.'<br>
debugfs: slotmap<br>
slotmap: Bad magic number in inode while reading slotmap
system file<br>
debugfs: stats<br>
Revision: 0.90<br>
Mount Count: 0 Max Mount Count: 20<br>
State: 0 Errors: 0<br>
Check Interval: 0 Last Check: Fri Nov 9
14:35:53 2012<br>
Creator OS: 0<br>
Feature Compat: 3 backup-super
strict-journal-super<br>
Feature Incompat: 16208 sparse extended-slotmap
inline-data metaecc xattr indexed-dirs refcount
discontig-bg<br>
Tunefs Incomplete: 0<br>
Feature RO compat: 7 unwritten usrquota grpquota<br>
Root Blknum: 129 System Dir Blknum: 130<br>
First Cluster Group Blknum: 64<br>
Block Size Bits: 12 Cluster Size Bits: 18<br>
Max Node Slots: 10<br>
Extended Attributes Inline Size: 256<br>
Label: SAN<br>
UUID: B4CF8D4667AF43118F3324567B90A987<br>
Hash: 3698209293 (0xdc6e320d)<br>
DX Seed[0]: 0x9f4a2bb7<br>
DX Seed[1]: 0x501ddac0<br>
DX Seed[2]: 0x6034bfe8<br>
Cluster stack: classic o2cb<br>
Inode: 2 Mode: 00 Generation: 1093568923
(0x412e899b)<br>
FS Generation: 1093568923 (0x412e899b)<br>
CRC32: 46f2d360 ECC: 04d4<br>
Type: Unknown Attr: 0x0 Flags: Valid System
Superblock<br>
Dynamic Features: (0x0)<br>
User: 0 (root) Group: 0 (root) Size: 0<br>
Links: 0 Clusters: 45340448<br>
ctime: 0x4ee67f67 -- Tue Dec 13 00:25:43 2011<br>
atime: 0x0 -- Thu Jan 1 02:00:00 1970<br>
mtime: 0x4ee67f67 -- Tue Dec 13 00:25:43 2011<br>
dtime: 0x0 -- Thu Jan 1 02:00:00 1970<br>
ctime_nsec: 0x00000000 -- 0<br>
atime_nsec: 0x00000000 -- 0<br>
mtime_nsec: 0x00000000 -- 0<br>
Refcount Block: 0<br>
Last Extblk: 0 Orphan Slot: 0<br>
Sub Alloc Slot: Global Sub Alloc Bit: 65535<span><font color="#888888"><br>
<br>
<br>
<br>
<br>
Marian<br>
<br>
</font></span><br>
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</blockquote>
</div>
<br>
</div>
</blockquote>
<br>
</blockquote>
<br>
</div></div></div>
</blockquote></div><br></div>