I used this command: hisat2-build -f genome.fa -p 4 genome
then I got 8 index files. Theoretically, there're 8 file named genome.1.ht2 to genome.8.ht2
but my output had .1.ht2 .2.ht2 .3.ht2 .4.ht2 .7.ht2 .8.ht2 and .2.sa .3.sa
lack of genome.5.ht2/.6.ht2 but 2 extra genome.2.sa/.3.sa
could you give me some help about that?