html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/4122#issuecomment-745520766,https://api.github.com/repos/pydata/xarray/issues/4122,745520766,MDEyOklzc3VlQ29tbWVudDc0NTUyMDc2Ng==,1872600,2020-12-15T19:39:16Z,2020-12-15T19:39:16Z,NONE,"I'm closing this the recommended approach for writing NetCDF to object stroage is to write locally, then push. ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,631085856
https://github.com/pydata/xarray/issues/4122#issuecomment-640548620,https://api.github.com/repos/pydata/xarray/issues/4122,640548620,MDEyOklzc3VlQ29tbWVudDY0MDU0ODYyMA==,1872600,2020-06-08T11:36:14Z,2020-06-08T11:37:21Z,NONE,"@martindurant, I asked @ajelenak offline and he reminded me that: 
> File metadata are dispersed throughout an HDF5 [and NetCDF4] file in order to support writing and modifying array sizes at any time of execution

Looking forward to `simplecache::` for writing in `fsspec=0.7.5`!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,631085856
https://github.com/pydata/xarray/issues/4122#issuecomment-639771646,https://api.github.com/repos/pydata/xarray/issues/4122,639771646,MDEyOklzc3VlQ29tbWVudDYzOTc3MTY0Ng==,1872600,2020-06-05T20:08:37Z,2020-06-05T20:54:36Z,NONE,"Okay @scottyhq, I tried setting `engine='h5netcdf'`, but still got:
```
OSError: Seek only available in read mode
```
Thinking about this a little more, it's pretty clear why writing NetCDF to S3 would require seek mode. 

I asked @martindurant about supporting seek for writing in `fsspec` and he said that would be pretty hard.  And in fact, the performance probably would be pretty terrible as lots of little writes would be required.  

So maybe it's best just to write netcdf files locally and then push them to S3.    

And to facilitate that,  @martindurant [merged a PR yesterday](https://github.com/intake/filesystem_spec/pull/309) to enable `simplecache` for writing in `fsspec`, so after doing:
```
pip install git+https://github.com/intake/filesystem_spec.git
```
in my environment, this now works:
```python
import xarray as xr
import fsspec

ds = xr.open_dataset('http://geoport.usgs.esipfed.org/thredds/dodsC'
                        '/silt/usgs/Projects/stellwagen/CF-1.6/BUZZ_BAY/2651-A.cdf')

outfile = fsspec.open('simplecache::s3://chs-pangeo-data-bucket/rsignell/foo2.nc', 
                      mode='wb', s3=dict(profile='default'))
with outfile as f:
    ds.to_netcdf(f)
```
(Here I'm telling `fsspec` to use the AWS credentials in my ""default"" profile)

Thanks Martin!!!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,631085856