Hello Renar, Thank you for the suggestion. I tried the configuration changes. They however do not seem to have any effect - the performance seems identical. I also tried all 4 combinations. I checked the documentation on the parameter "dioSmallSeqWriteBatching" and it states that small IOs are considered under 64kb. I've also found a parameter "dioSmallSeqWriteThreshold" but my GPFS version (5.1.9.0) claims that it's an unknown attribute.
-- S přáním pěkného dne / Best regards Mgr. Peter Hruška IT specialista M Computers s.r.o. Úlehlova 3100/10, 628 00 Brno-Líšeň (mapa<https://mapy.cz/s/gafufehufe>) T:+420 515 538 136 E: peter.hru...@mcomputers.cz<mailto:peter.hru...@mcomputers.cz> www.mcomputers.cz<http://www.mcomputers.cz/> www.lenovoshop.cz<http://www.lenovoshop.cz/> [cid:7960eefed7c420f97bb5d3ea3ccc383e18a57bcd.camel@mcomputers.cz-0] On Mon, 2024-03-11 at 13:56 +0000, Grunenberg, Renar wrote: EXTERNÍ ODESÍLATEL Hallo Peter, my to cents to this. Set the diasbleDIO=yes Parameter to DEFAULT and use the ! dioSmallSeqWriteBatching 1 disableDIO 0 And give it a try. Regards Renar Renar Grunenberg Abteilung Informatik - Betrieb HUK-COBURG Bahnhofsplatz 96444 Coburg Telefon: 09561 96-44110 Telefax: 09561 96-44104 E-Mail: renar.grunenb...@huk-coburg.de Internet: www.huk.de ________________________________ HUK-COBURG Haftpflicht-Unterstützungs-Kasse kraftfahrender Beamter Deutschlands a. G. in Coburg Reg.-Gericht Coburg HRB 100; St.-Nr. 9212/101/00021 Sitz der Gesellschaft: Bahnhofsplatz, 96444 Coburg Vorsitzender des Aufsichtsrats: Prof. Dr. Heinrich R. Schradin. Vorstand: Klaus-Jürgen Heitmann (Sprecher), Stefan Gronbach, Dr. Hans Olav Herøy, Dr. Helen Reck, Dr. Jörg Rheinländer, Thomas Sehn, Daniel Thomas. ________________________________ Diese Nachricht enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese Nachricht irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Nachricht. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Nachricht ist nicht gestattet. This information may contain confidential and/or privileged information. If you are not the intended recipient (or have received this information in error) please notify the sender immediately and destroy this information. Any unauthorized copying, disclosure or distribution of the material in this information is strictly forbidden. ________________________________ Von: gpfsug-discuss <gpfsug-discuss-boun...@gpfsug.org>Im Auftrag von Peter Hruška Gesendet: Montag, 11. März 2024 14:22 An: gpfsug-discuss@gpfsug.org Betreff: [gpfsug-discuss] Slow performance on writes when using direct io Hello, We encountered a problem with performance of writes on GPFS when the application uses direct io access. To simulate the issue it is enough to run fio with option direct=1. The performance drop is quite dramatic - 250 MiB/s vs. 2955 MiB/s. We've tried to instruct GPFS to ignore direct IO by using "disableDIO=yes". The directive didn't have any effect. Is there any possibility how to achieve that GPFS would ignore direct IO requests and use caching for everything? -- S přáním pěkného dne / Best regards Mgr. Peter Hruška IT specialista M Computers s.r.o. Úlehlova 3100/10, 628 00 Brno-Líšeň (mapa<https://mapy.cz/s/gafufehufe>) T:+420 515 538 136 E: peter.hru...@mcomputers.cz<mailto:peter.hru...@mcomputers.cz> www.mcomputers.cz<http://www.mcomputers.cz/> www.lenovoshop.cz<http://www.lenovoshop.cz/> [cid:image001.png@01DA73C4.13BF9D80] _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at gpfsug.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss_gpfsug.org
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