Just throwing some ideas out here... if all the failed drives were on one server, its likely the blocks are replicated on other nodes. So you can
hdfs dfsadmin - report |head -13 and look for under replicated blocks you can put that in a loop and watch the count go down, eventually you will be left with actual missing blocks while true do hdfs dfsadmin - report |head -13 sleep 600 done you can also run some queries https://knpcode.com/hadoop/hdfs/how-to-fix-corrupt-blocks-and-under-replicated-blocks-in-hdfs/ Its very likely most of the data is replicated on other disks/nodes you may also get some insight to actual path names by tailing the namenode.log Just ideas off the top of my head Good luck ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Monday, September 13th, 2021 at 7:03 PM, Bob Metelsky <bob.metel...@pm.me> wrote: > Hi berfore doing that, I would ls-ltR > > filename.txt on each disk and see if there are hints/references to the > original file system. That may help provide a more meaningful path to to > HD’s-site.xml. Generally it sounds pretty close > > Let us know how it goes > > On Mon, Sep 13, 2021 at 5:59 PM, Andrew Chi <chi.and...@gmail.com> wrote: > >> I've had a recent drive failure that resulted in the removal of several >> drives from an HDFS datanode machine (Hadoop version 3.3.0). This caused >> Linux to rename half of the drives in /dev/*, with the result that when we >> mount the drives, the original directory mapping no longer exists. The data >> on those drives still exists, so this is equivalent to a renaming of the >> local filesystem directories. >> >> 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 >> >> Where it's not clear how {a,b,c} map on to {x,y,z}. The blocks have been >> preserved within the directories, but the directories have essentially been >> randomly permuted. >> >> Can I simply go to hdfs-site.xml and change dfs.datanode.data.dir to the new >> list of comma-separated directories /hadoop/data/path/{x,y,z}? Will the >> datanode still work correctly when I start it back up? >> >> Thanks! >> Andrew
