Before replying, I want to note that I think I've stumbled upon three (perhaps related) issues (some of which might just be configuration error): * AFS file access getting stuck; (seems to be solved by increasing the number of `fileserver` threads from `-p 4` to `-p 128`;) * trying to `SIGTERM` or `SIGKILL` a "stuck" process, takes Linux (in kernel code) to 100% CPU; * having `-jumbo -rxmaxmtu 9000` on the server, but not on the client, yields poor performance;
This new thread (which I was just going to open myself) is related to the third problem of mismatch between server and client jumbo frames setting. On Wed, Nov 20, 2019 at 8:59 PM Kostas Liakakis <[email protected]> wrote: > (Yesterday over wireless I didn't use Jumbo frames, but the day > before, where the same thing happened, I was using them.) > > Does this mean that '"the other day with jumbo frames" was over GigE ? Does > this happen over GigE with jumbo frames disabled a well? So, apparently having `-jumbo -rxmaxmtu 9000` on the server, but not configuring jumbo frames on the client yields poor performance. (Also the "getting stuck" issue happens regardless of this other problem.) Without touching the `fileserver` parameters, none of the following seem to work: * `afsd` with `-rxmaxmtu 9000` but without jumbo frames configured on the network card; (clear missconfiguration on my part); * `afsd` with `-rxmaxmtu 1500` but over GigaBit Ethernet (and without jumbo frames configured on the network card); (an usual client on the same network without jumbo frames support;) * `afsd` with `-rxmaxmtu 1500` but over Wifi (which is capable of ~14 MiB receive); (clearly no jumbo frames are supported;) * as mentioned only by matching the server configuration seem to solve the issue; * (encryption is disabled;) I've changed the `fileserver` parameters by removing `-jumbo` and updating `-rxmaxmtu 1400` (I also intend to use this over WAN, thus over PPPoE and VPN, which will add quite an impact on the MTU). Now the client works OK, however if I start the `afsd` client on the server itself (i.e. over `loopback` network), where previously (with `-jumbo`) I was able to max-out the disks (~300 MiB/s), now seems to be capped at around ~120MiB. (The packet-per-second is aroun ~120K...) > I 've seen problems finally attributed to jumbo frames where some > configuration change on a switch someplace amount the path rendered them > unusable. I don't think this is the case here. I have only one switch between the client and the server (no other network equipment), and I haven't encountered performance problems (even with regard to jumbo frames). Ciprian. _______________________________________________ OpenAFS-info mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-info
