Downloading viral genome database for viral read classification - Metagenomics

1.  Kraken2 Metagenomic Virus Database - redirects to globus - does not have an option to download
   
   
2. Default kraken2 command:
• kraken2-build --download-library viral --db $DBNAME
  
  Results in the error - adding --use-ftp did not help
  rsync: getaddrinfo: ftp.ncbi.nlm.nih.gov 873: Name or service not known
  rsync error: error in socket IO (code 10) at clientserver.c(127) [Receiver=3.1.3]
  Error downloading assembly summary file for viral, exiting.
  
  
• Tried changing code in specific scripts based on this error thread - still no luck! :(
• Tried changing code in specific scripts based on this error thread - still no luck! :(
  
  
3. A python script that helps with updating the kraken databases :
• error - FileNotFoundError: [Errno 2] No such file or directory: 'assembly_summary_refseq.txt'
  
  
4. Downloaded NCBI Viral database from here - have not tested - but fasta sqeuences needed to converted to kraken2 database format.
   
   
5. Downloaded Viral RefSeq database from a PeerJ paper - worked!
• Pre-compiled databases
• Looks comprehensive! Size is big (6.6 gb)
• Could classify the viral reads using kraken2 command