<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="">I was reading this slide deck on GPFS metadata sizing and I ran across something</div><div class=""><a href="http://files.gpfsug.org/presentations/2016/south-bank/D2_P2_A_spectrum_scale_metadata_dark_V2a.pdf" class="">http://files.gpfsug.org/presentations/2016/south-bank/D2_P2_A_spectrum_scale_metadata_dark_V2a.pdf</a></div><div class=""><br class=""></div><div class="">On slide 51 it says</div><div class=""><br class=""></div><div class=""><i class="">"Max replicas for Data, multiplies the MD capacity used<br class=""><br class="">• Reserves space in MD for the replicas even if no files replicated!”</i></div><div class=""><br class=""></div><div class="">This is something I did not realize - setting data replicas to 2 or even 3 consumes metadata space even if you are not using the data replicas. For metadata replicas it says unused replica’s have little impact - great. I like to set data and metadata replica’s to 3 when I make a filesystem even when the initial replicas used are 1 since you never know what will change down the road. However this makes me wonder about that idea for the data replica’s - it’s really expensive metadata spacewise.</div><div class=""><br class=""></div><div class="">This information was written prior to GPFSv5 when subblocks changed from only 32. Does it still hold true that unused data replica’s use metadata space with v5? </div><div class=""><br class=""></div><div class="">thanks</div><div class="">Russell</div><div class=""><br class=""></div><div class=""><br class=""></div></body></html>