# Restarting ACCESS-AM3 mid run **URL:** \ **Category:** AM3\ **Tags:** help\ **Created:** [1 October 2026 07:37 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051 "2026-10-01T07:37:11Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![paocorrales](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/paocorrales/32/3326_2.png) [@paocorrales](https://forum.access-hive.org.au/u/paocorrales)\ **Post date:** [1 October 2026 07:37 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/1 "2026-10-01T07:37:11Z")
Hi! I have an experiment that ran from Jan 2007 to Dec 2008, the experiment has already finished. For a reason, I have to re-run Aug 2007. What would be the correct way to restart the model to run only that month? I would usually change the initial conditions to use the corresponding dump file and initial date and start a new run. But if I do that, the suite will run the reconfiguration step before running the model. I’d like to avoid it since it is not what happens in a “normal” run. I already tried starting the suite and skipping the recon step, but the model complains that there is no `astart` file. When I copy the initial conditions with that name, the model complains that there is no xhist ☹ ---
**Author:** ![paocorrales](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/paocorrales/32/3326_2.png) [@paocorrales](https://forum.access-hive.org.au/u/paocorrales)\ **Post date:** [6 October 2026 06:26 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/2 "2026-10-06T06:26:41Z")
I’ve been exploring the suite and the documentation and I found an option `BITCOMP_NRUN` that activates `l_nrun_as_crun=.true.`. It sounded like it was the solution, according to the documentation: > can be set to treat a new run in the same way as a continuation run. This effectively bypasses special behaviour on timestep one. However, the model still complains that it needs the `am3.xhist` file. I can potentially copy one of those from a previous run, but the content won’t match anyway. ---
**Author:** ![lachlanswhyborn](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/lachlanswhyborn/32/1837_2.png) [@lachlanswhyborn](https://forum.access-hive.org.au/u/lachlanswhyborn)\ **Post date:** [6 October 2026 23:39 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/3 "2026-10-06T23:39:50Z")
Ahh good question- I think what you should be able to do is play the workflow (`cylc play`) and then trigger the specific task you want to re-run, before Cylc times out and shuts the workflow down again (which I think is 5mins)? I think the date should be the cycle point, so `cylc trigger access-am3-configs////atmos`? ---
**Author:** ![paocorrales](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/paocorrales/32/3326_2.png) [@paocorrales](https://forum.access-hive.org.au/u/paocorrales)\ **Post date:** [7 October 2026 02:08 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/4 "2026-10-07T02:08:36Z")
Thanks for that one! It didn’t work immediately for me, it returned `Command queued` but then nothing else (no job sent to the queue). I tried a few things and this worked: ```auto cylc set --pre=all access-am3-configs_21st/run16//20070801T0000Z/atmos_main ``` It seems you need to set all the dependencies to success, even when the workflow has already finished successfully. So, now I got atmos\_main in the queue 🎉 > Note for people in the future. Those double // are not a typo, trust me 😅 But, it didn’t run the model. I got a bunch of warnings like this: ```auto IO: Open: /home/565/pc2687/cylc-run/access-am3-configs_21st/run16/share/data/History_Data/am3a.pg20081231 on unit 19 (Server = 23) loadHeader: The file on unit 19 does not have enough content to load the header ???????????????????????????????????????????????????????????????????????????????? ?????????????????????????????? WARNING ?????????????????????????????? ? Warning code: -10 ? Warning from routine: INIT_PP_CRUN ? Warning message: Error: Failed to load fixed header. ? Warning from processor: 0 ? Warning number: 66 ???????????????????????????????????????????????????????????????????????????????? ``` I think it is still reading the last `am3.xhist` with the last cycle information. I’m tempted to manually edit the file and see what happens. ---
**Author:** ![paocorrales](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/paocorrales/32/3326_2.png) [@paocorrales](https://forum.access-hive.org.au/u/paocorrales)\ **Post date:** [7 October 2026 06:31 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/5 "2026-10-07T06:31:37Z")
It worked!! So, I changed the `am3.xhist` file to match what I imagine it would need to run Aug 2007 (dump and output stream file names) and the model ran without any complaints, triggering with: ```auto cylc set --pre=all access-am3-configs_21st/run16//20070801T0000Z/atmos_main ``` I also checked a few variables to see if they match and yes, diff = 0 🎉 ---
**Author:** ![bethanwhite](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/bethanwhite/32/3080_2.png) [@bethanwhite](https://forum.access-hive.org.au/u/bethanwhite)\ **Post date:** [7 October 2026 06:38 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/6 "2026-10-07T06:38:04Z")
I have been reading along wondering if there would be a (relatively) simple fix to be discovered. This is great news, Pao! ---
**Author:** ![lachlanswhyborn](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/lachlanswhyborn/32/1837_2.png) [@lachlanswhyborn](https://forum.access-hive.org.au/u/lachlanswhyborn)\ **Post date:** [7 October 2026 22:42 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/7 "2026-10-07T22:42:55Z")
Nice, good to hear you found a solution, it has always bothered me that I often couldn’t get `cylc trigger` to work the way I wanted it to. ---
**Author:** ![lachlanswhyborn](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/lachlanswhyborn/32/1837_2.png) [@lachlanswhyborn](https://forum.access-hive.org.au/u/lachlanswhyborn)\ **Post date:** [8 October 2026 00:15 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/8 "2026-10-08T00:15:03Z")
@paocorrales did you need to `cylc play` the workflow before calling `cylc set --pre=all ...`? ---
**Author:** ![paocorrales](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/paocorrales/32/3326_2.png) [@paocorrales](https://forum.access-hive.org.au/u/paocorrales)\ **Post date:** [8 October 2026 05:44 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/9 "2026-10-08T05:44:44Z")
Yes, the suite has stopped so `cylc play` and then `cylc set --pre=all ...`. > [@lachlanswhyborn](#): > > it has always bothered me that I often couldn’t get `cylc trigger` to work the way I wanted it to. Well, I had to trigger the netCDF conversion also and it worked with `cylc trigger`. There is something in the logic of the suite/cylc that I still don’t understand. ---
**Author:** ![Scott](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/scott/32/37_2.png) [@Scott](https://forum.access-hive.org.au/u/Scott)\ **Post date:** [8 October 2026 23:06 UTC](https://forum.access-hive.org.au/t/restarting-access-am3-mid-run/7051/10 "2026-10-08T23:06:47Z")
There’s some docs on retrying sections of a workflow at [Interventions — Cylc 8.6.6 documentation](https://cylc.github.io/cylc-doc/stable/html/user-guide/interventions/index.html#)