Bowtie2 single seq mapping

[sigma]

Hi friends,

I'm trying to map some sequences (length : 17) in the initial chromosome sequence.
So i use this command :

/usr/local/bowtie2-2.0.0-beta5/bowtie2 -f --end-to-end -x Indexed_CHR10 -U INPUT.fasta -S OUTPUT.sam

so in INPUT it's a fasta format with my 17-mers
The problem is that i have warnings and so the mapping is not good.

Warning: skipping read 'tttttttgcaatagtag' because length (0) <= # seed mismatches (0)
Warning: skipping read 'tttttttgcaatagtag' because it was < 2 characters long

advance thanks,
Sigma

[sigma]

It's working, the problem was really simple :
actually i've given a bad fasta file format :

>SEQ

and not :

>ID
SEQ
...

regards,
Sigma