Hello, Ceph users, my erasure-coded pool is inconsistent with the documentation, apparently existing objects cannot be appended to. The documentation states the following: ================ https://docs.ceph.com/en/latest/rados/operations/erasure-code/ By default, erasure-coded pools work only with operations that perform full object writes and appends (for example, RGW). ================ Appends do not work for me: $ ceph osd pool create test-ec erasure k5m2 pool 'test-ec' created $ echo -n 12345678 | rados --pool test-ec put testobj - $ rados --pool test-ec stat testobj test-ec/testobj mtime 2025-09-05T12:51:20.000000+0200, size 8 $ echo -n 12345678 | rados --pool test-ec put testobj - --offset 8 error putting test-ec/testobj: (95) Operation not supported $ echo -n 12345678 | rados --pool test-ec append testobj - error appending test-ec/testobj: (95) Operation not supported When I enable the allow_ec_overwrites flag, everything works as expected: $ ceph osd pool set test-ec allow_ec_overwrites true set pool 73 allow_ec_overwrites to true $ echo -n 12345678 | rados --pool test-ec put testobj - --offset 8 $ echo -n 12345678 | rados --pool test-ec append testobj - $ rados --pool test-ec stat testobj test-ec/testobj mtime 2025-09-05T12:54:30.000000+0200, size 24 Should the documentation be fixed somehow (maybe appending works only at certain block sizes or whatever), or am I doing something incorrect? My cluster is Ceph 19.2.2. Thanks, -Yenya -- | Jan "Yenya" Kasprzak <kas at {fi.muni.cz - work | yenya.net - private}> | | https://www.fi.muni.cz/~kas/ GPG: 4096R/A45477D5 | We all agree on the necessity of compromise. We just can't agree on when it's necessary to compromise. --Larry Wall