Hi Jonathan, I assume this is using GNR, right ? which Scale version are you using ? Background: there was a known issue with the bandwidth_low event when GNR is used. best regards Mathias Dietz Storage Scale RAS Architect IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Wolfgang Wendt Geschäftsführung: David Faller Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294 ________________________________ From: gpfsug-discuss <gpfsug-discuss-bounces at gpfsug.org> on behalf of Jonathan Buzzard via gpfsug-discuss <gpfsug-discuss at gpfsug.org> Sent: Tuesday, August 25, 2026 4:47 PM To: gpfsug-discuss <gpfsug-discuss at gpfsug.org> Cc: Jonathan Buzzard <jonathan.buzzard at strath.ac.uk> Subject: [EXTERNAL] [gpfsug-discuss] Bandwidth low I have a number of new DSS-G servers that are showing a bandwidth_low tip. Searching suggests this is something to do with a large pagepool and insufficient network bandwidth. Except all these servers have dual 200Gbps Ethernet connections in a 802.3ad bond to two SN3700m switches in an MLAG. After lots of digging around the maxMBpS is set to 80000 which is what it should be. I figure as far as Ethernet networking goes this is about as good as it gets. It is way better than our old DSS-G which for a long time only had dual 40Gbps Ethernet on each node, though this is now been maxed out at quad 40Gbps Ethernet on each node. Those nodes are not showing the tip despite their lower total network bandwidth. The only thing I can think is that 200Gbps is an unusual Ethernet speed which is confusing the calculations? I know Lenovo could not supply 200Gbps Ethernet optics and DAC's and I had to supply my own. JAB. -- Jonathan A. Buzzard Tel: +44141-5483420 HPC System Administrator, ARCHIE-WeSt. University of Strathclyde, John Anderson Building, Glasgow. G4 0NG _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at gpfsug.org https://urldefense.proofpoint.com/v2/url?u=http-3A__gpfsug.org_mailman_listinfo_gpfsug-2Ddiscuss-5Fgpfsug.org&d=DwIGaQ&c=BSDicqBQBDjDI9RkVyTcHQ&r=-MaHePVLWSGaTuAdHQuYYijcz_c4mSZc_nxIEMnqfSM&m=Tj9xwUSzxhplEQ-sFL40lLKkeT7mwMyWEiqxwvqOOswUcUmpC8tGj_3mFpZJ_alg&s=VP9Bz2jfBILZfKfhLjlsspGHCiaYLDZX1nBy6mb-9xA&e= -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20260825/8b9b5f68/attachment-0001.html>