/stand no superblock.. no alternate superblock.. file system backup?

[Bill McNAMARA_1]

Hi,
I have to be a bit brief with the description because it seems to be one of those Monday machine days (machines made on mondays)


ISL>hpux ll
shows can't open directory.
no kernel

I boot from a second bootable disk vgimport the vg00 of my first disk and mount / .
I then try to fsck my stand on disk1 with fsck -F hfs -b=32 ...
and -o full
and no alternate sbs can be found.
I recall there is a directory backup of the sbs that I could restore. but can't remember where..

I don't even know if the fsck will correct the problem, the stand of disk1 after vgimport does mount.. but doesn't appear to hpux on an ll.

the lifls of the disk1 shows all okay.
ISL works too! hpux does do the ll, but doesn't see the /stand kernel that I can mount and see on the other OS..

I'm not sure if the alternate sb is a problem, but it's the only idea I have at the moment.

Any ideas?
disk1 is potentially bootable and normally not in a vg on the disk2 that does boot.. except for this troubleshooting exercise.


Later,
Bill

[eran maor]

Hi Bill

The workaround is to find an auxiliary super block with the following small C program, and copy it with dd to a location visited by fsck_vxfs.
The program scans the lvol and list the
superblock and alternate superblock.

/* Compile and redirect input to come from the raw device with the */
/* file system for which you need to find auxiliary super blocks */
/* e.g. cc fsb.c; a.out < /dev/vg00/rlvol5 */

#include
#include
#include
#include

main()
{
int address = 0;
union {
char buf[8192];
int magic;
} block;

while ( read (0, &block, 8192) )
{
if ( block.magic == VX_MAGIC )
printf("Superblock at block %d ...\n", address);
if ( block.magic == VX_AUMAGIC )
printf("Auxiliary superblock at block %d ...\n", address);
address += 8192;
}
}

but i have to say that it doesnt seem to me a sbs problem .

try this and i will try to think about other idea's

[eran maor]

Hi Bill

the dir of the superblock is in : /etc/sbtab

[eran maor]

Hi Bill

i know that you know the answer but use the command of the fsck with -b alternate superblock .

i hope that you have a ignite backup of the system .

[Jerry Zhang]

The super block table is at:
/var/adm/sbtab

[Bill McNAMARA_1]

I really don't want to reinstall this system.. there's too much to reconfigure.

What's really frustrating is that I can see the kernel when I mount the disk on from other bootable disk.
There is no fsck on any of the imported lvols required.

Perhaps its more to do with stable storage or even the LIF area itself?

Bill

[Wodisch]

Hello Bill,

on HPUX system the first alternate superblock was
always #16, only on other (BSD) UN*Xs it was #32.

HTH,
Wodisch