samtools sort Failed to open file问题

• 报错

[bam_sort_core] merging from 2525 files and 1 in-memory blocks...
[E::hts_open_format] Failed to open file "2_5_merged.sort.bam.tmp.1020.bam" : Too many open files

• 原脚本

samtools sort  -o w.sort.bam w.merged.bam

• 排查原因：临时文件生成太多导致，改善方法就是增大临时文件可写入的大小来减少文件个数

$ samtools sort
Usage: samtools sort [options...] [in.bam]
-m INT     Set maximum memory per thread; suffix K/M/G recognized [768M]

#改写参数
samtools sort -m 2G -o w.sort.bam w.merged.bam