mkfs.ext4: No such device or address while trying to determine filesystem size

[jackson byers]

trying to format a partition  as ext4
getting following error

[root at f14 ~]# mkfs.ext4 /dev/sdc7
mke2fs 1.41.12 (17-May-2010)
mkfs.ext4: No such device or address while trying to determine filesystem size
[root at f14 ~]#

I did this same command earlier today and it worked.

Since then, I made some kind of error copying to that partition,
after it was mounted to /mnt/sdc7.
So I was trying to reformat.

Also, now if I try to  mount it I can't even see what is in it:

[root at f14 ~]# mount /dev/sdc7 /mnt/sdc7
mount: /dev/sdc7 is not a valid block device

This must be newbie stuff, but I am lost.


mount shows sdc9 for example
/dev/sdc9 on /grubp type ext3 (rw)

but fdisk -l shows only sda, sdb,
nothing for sdc

df -kh does show sdc9,  nothing for sdc7
root at f14 ~]# df -kh
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda8              17G  8.1G  7.5G  52% /
tmpfs                1007M  444K 1006M   1% /dev/shm
/dev/sdc9              16M  1.5M   13M  11% /grubp
/dev/sda3              21G  9.2G   11G  48%
/media/54c84c0a-040b-43bd-8887-202519baaae2_
/dev/sda6             8.1G  7.0G  1.1G  87% /media/rootusb6_
/dev/sda7              16G  7.3G  7.4G  50%
/media/c2f44d00-09e6-45b2-9a14-a0a765716005_
/dev/sda2              21G  7.5G   13G  38% /media/rootusb2_
/dev/sda1              24G   18G  5.8G  76% /media/rootusb_
[root at f14 ~]#



Jack