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User-Agent: Mozilla/5.0 Galeon/1.2.6 (X11; Linux i686; U;) Gecko/20020913

Description of problem:
sometimes when it is made a new partition fdisk shows a message about it is
necesary reboot the system for to use the new fs. And this is not TRUE!!

--
[..fdisk shell...]
Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource
busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
---

it is possible to use partx for to solve this trouble
--partx--
/*
 * Given a block device and a partition table type,
 * try to parse the partition table, and list the
 * contents. Optionally add or remove partitions.
 *
 * [This is not an fdisk - adding and removing partitions
 * is not a change of the disk, but just telling the kernel
 * about presence and numbering of on-disk partitions.]
 *
 * Call:
 *	partx [-{l|a|d}] [--type TYPE] [--nr M-N] [partition] wholedisk
 * where TYPE is {dos|bsd|solaris|unixware|gpt}.
 *
 * Read wholedisk and add all partitions:
 *	partx -a wholedisk
 *
 * Subdivide a partition into slices (and delete or shrink the partition):
 * [Not easy: one needs the partition number of partition -
 *  that is the last 4 or 6 bits of the minor; it can also be found
 *  in /proc/partitions; but there is no good direct way.]
 *	partx -a partition wholedisk
 *
 * Delete all partitions from wholedisk:
 *	partx -d wholedisk
 *
 * Delete partitions M-N from wholedisk:
 *	partx -d --nr M-N wholedisk
 *
 * aeb, 2000-03-21 -- sah is 42 now
 */
--end--

I dont know about sfdisk, but this false reboot message must be changed by other
!!! 

more info here:
http://www.math.tau.ac.il/~didi/editing-busy-partition-tables.html
to

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1.fdisk
2.to add one partition and :w
3.reboot? NO
    

Additional info: