That's very good to know. Thanks for the update. I was wondering what happened
:-)
Good to hear it was seamless/easy
Bob
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Friday, September 17th, 2021 at 11:33 AM, Andrew Chi <chi.and...@gmail.com>
wrote:
> Just wanted to give a quick update. The recovery was successful, and it turns
> out that you can rename the datanode directories (and just update
> dfs.datanode.data.dir in hdfs-site.xml). Simply start the datanode up, and it
> will "just work". At least for Hadoop 3.3.0, the namenode does not know or
> care about the datanode's local filesystem organization, as long as all the
> blocks are accounted for when the datanode starts up.
>
> Originally, we had:
> /hadoop/data/path/a
> /hadoop/data/path/b
> /hadoop/data/path/c
>
> Now we have:
> /hadoop/data/path/x
> /hadoop/data/path/y
> /hadoop/data/path/z
>
> Due to some drive failures and subsequent shuffling of /dev/sd*, we had lost
> the mapping of {a,b,c} on to {x,y,z}. Fortunately, the design of HDFS
> decouples the namespace from the physical data storage, and therefore this
> datanode recovery was seamless.
