# Using mv command in AWS environment with fusion **URL:** \ **Category:** Ask for help\ **Tags:** nextflow, fusion\ **Created:** [October 27, 2023, 2:34pm UTC](https://community.seqera.io/t/using-mv-command-in-aws-environment-with-fusion/231 "2023-10-27T14:34:06Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![ggabernet](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/ggabernet/32/65_2.png) [@ggabernet](https://community.seqera.io/u/ggabernet)\ **Post date:** [October 27, 2023, 2:34pm UTC](https://community.seqera.io/t/using-mv-command-in-aws-environment-with-fusion/231/1 "2023-10-27T14:34:06Z")
Hi all, I had a nextflow process that used the move command to change the name of a folder inside the work directory, and had issues running it on AWS with fusion. Nextflow terminated with the `Missing declared output files` error, I guess because the `mv` command on the Fusion file system was taking too long and Nextflow did not wait for it to finish. Changing the `mv` command to `cp` solved the issue but of course in other infrastructure this makes the process slower. I was wondering if there is another possible solution to this. ---
**Author:** ![jordeu](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/jordeu/32/90_2.png) [@jordeu](https://community.seqera.io/u/jordeu)\ **Post date:** [October 28, 2023, 4:23am UTC](https://community.seqera.io/t/using-mv-command-in-aws-environment-with-fusion/231/2 "2023-10-28T04:23:33Z")
To move a “folder” on a block storage is an expensive operation because there is no concept of “folder” and no concept of “move”. So the implementation has to do a copy&remove of each single file inside the folder. But this is supported by Fusion and the performance should be similar to the equivalent copy (that it’s a bit more performance but also has similar problems). So, I guess that in your case there was some problem. Can you send me the `.fusion.log` file of that process that was doing the move?