Repartitioning with format: bad superblock produced
Hi everybody,
i wanted to increase the size of my / partition in solaris 9.
The partition table had the following entries, among others:
PartTagFlagCylSizeBlocks
0rootwm363-16101.72GB1248/0/03605472
2backupwm0-2461933.92GB24620/0/0 71127180
7homewm1611-2468 31.70GB23008/0/0 6647112
# First question: is backup always covering all the disk?
# Now i want to reduce the size of home.
# I will cut the first cylinders and start it from cyl 3800.
# Then i just typed:
format
0# this was the disk selection
partition
7# this is partition home, as in table above
Enter partition id tag[home]:
Enter partition permission flag[wm]:
Enter new starting cyl[1611]: 3800
Enter partition size: 28.68gb
label
Ready to label disk, continue? y
print
# below only the partitions under interest ...
PartTagFlagCylSize
0rootwm363-16101.72GB
7homewm3800-21936 28.68GB
# now i want to use the gigas made free in the / partition.
# So i continued from the same point as above ... (the partition prompt)
0# this selects the / partition
Enter partition id tag[root]:
Enter partition permission flag[wm]:
Enter new starting cyl[363]:
Enter partition size: 3437c
# here i calculated the size from the first root cyl (363) to the first home cyl (3800).
# Continuing ...
label
Ready to label disk, continue? y
print
# below only the partitions under interest ...
PartTagFlagCyl Size
0rootwm363-37994.7GB
7homewm3800-2193628.68GB
quit
quit
reboot
# the boot stoped in fsck with the message:
/dev/rdsk/c1t2d0s7: BAD SUPERBLOCK AT 16: MAGIC NUMBER WRONG
/dev/rdsk/c1t2d0s7: USE AN ALTERNATIVE SUPERBLOCK TO SUPLY NEEDED INFORMATION
/dev/rdsk/c1t2d0s7: e.g. fsck -F ufs -o b=# [special ...]
/dev/rdsk/c1t2d0s7: where # is the alternative superblock
# It seems that Solaris complains only with the /export/home partition, which had its size reduced,
# but not with the / partition, which was increased.
# ? I do not know what i have to give as superblock. Any help ?
# Thanks enormously for a help!
[2294 byte] By [
tunelera] at [2007-11-27 0:37:03]
# 1
format is not designed to change the size of filesystems.
It just edits the partition table.
So you just created an invalid filesystem.
Solaris in fact doesnt have a simple tool for resizing filesystems.
growfs can expand them, but is normally used in conjunction with svm and it can't be used on the root fs.
Theres no tool available to shrink filesystems.
The / filesystem that you just extended should be ok (or at least not corrupt).
Except that it won't see the new space.
As far as /export/home goes,
If you know the previous settings, change it back and reboot and if your really lucky, your filesystem will be intact.
If not, you can newfs /export/home. But you're probably better off reinstalling the system and picking a more appropriate size for /
In genrnal, the easiest way to get some extra space in / is to pick a biggish directory like /var,
copy it only /export/home and symlink it back the original location.
# 5
Hi all,
i reset back to the original partition table. I had to boot from cdrom in single
user mode to do that, since exporting the variable NOINUSE_CHECK was
not working.
I will then symlink /usr/local and /var to /export/home.
Are you sure moving /var is ok?
A simple command `cp -pr /var /export/home/var` freezes.
It seems to freeze in the directory /var/sadm/wbem/snmp/map
when transfering the fifo files:
# file /var/sadm/wbem/snmp/*
/var/sadm/wbem/snmp/_adapter_rcv.fifo: fifo
/var/sadm/wbem/snmp/_adapter_snd.fifo: fifo
Should i break /var into pieces and transfere only part of it to /export/home?
Thanks ...
# 6
> Hi all,
> i reset back to the original partition table. I had
> to boot from cdrom in single
> user mode to do that, since exporting the variable
> NOINUSE_CHECK was
> not working.
>
> I will then symlink /usr/local and /var to
> /export/home.
> Are you sure moving /var is ok?
No. /var also mounts before non-OS filesystems.
If you boot to single-user mode, /, /usr, /var, /var/adm, and /var/run should all be accessible either as subdirectories or as separate mount points.
If you symlink it to some other filesystem, then that filesystem won't yet be mounted and these directories will not be accessible.
> A simple command `cp -pr /var /export/home/var`
> freezes.
> It seems to freeze in the directory
> /var/sadm/wbem/snmp/map
> when transfering the fifo files:
> # file /var/sadm/wbem/snmp/*
> /var/sadm/wbem/snmp/_adapter_rcv.fifo: fifo
> /var/sadm/wbem/snmp/_adapter_snd.fifo: fifo
Don't use 'cp'. Use 'tar' or 'cpio'.
--
Darren
