Hi Andy, we did turn off async i/o in two of the 4 CMS servers 20 days ago. Since then, we never observed thread saturation, neither in those 2 servers nor in the 2 with async i/o on. So unfortunately we cannot comment further at the moment. Lucia -- Reply to this email directly or view it on GitHub: https://github.com/xrootd/xrootd/issues/1799#issuecomment-1333453644 You are receiving this because you commented. Message ID: <[log in to unmask]> ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-DEV list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-DEV&A=1