Hi, In ATLAS TDAQ we have the following problem: there is a huge number of small files (~5 million) that we are storing in EOS as compressed tar archives. Then to read a single small file we have to bring back from EOS an entire archive file which can be up to 6 GBs. This is very inneficient and takes a lot of time. Is there a way to programatically extract just the small file we need from the archive directly on the EOS side? Or do you know a file format which can be used instead of tar that will return us only a subset of data from EOS, not only a complete file? What can the XrootD API give to us? Cheers, Alex ---- Alexandru Dan Sicoe MEng, Research Fellow CERN, PH-ADT Office: 40-5-D01 Phone: +41 (0) 22 76 71113 ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-L list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-L&A=1