Mike Parker

As of v1.21.1 and OpenJDK 21.0.4, this issue also appears to affect *.dat files in the playerdata directory:

prompt> find . -not -readable -exec ls -l {} \;
-rw------- 1 minecraft minecraft 1618 Aug 18 12:40 ./world_the_end/level.dat_old
-rw------- 1 minecraft minecraft 1621 Aug 18 12:45 ./world_the_end/level.dat
-rw------- 1 minecraft minecraft 1578 Aug 18 12:40 ./world/level.dat_old
-rw------- 1 minecraft minecraft 21555 Aug 16 20:40 ./world/playerdata/00000000-0000-0000-0009-01ff911f72ad.dat
-rw------- 1 minecraft minecraft 21548 Aug 16 20:40 ./world/playerdata/00000000-0000-0000-0009-01ff911f72ad.dat_old
-rw------- 1 minecraft minecraft 1575 Aug 18 12:45 ./world/level.dat
-rw------- 1 minecraft minecraft 1527 Aug 18 12:40 ./world_nether/level.dat_old
-rw------- 1 minecraft minecraft 1528 Aug 18 12:45 ./world_nether/level.dat

I'm experiencing the same issue as reported above, namely an inability to backup files as an unprivileged user.

I'm seeing 1.18 also make significantly more (almost continual) disk accesses wrt 1.17.1 I was running previously. From an strace of the running java process, it appears to be constantly lstat'ing non-existent c.-*.mcc files. The following strace was taken with the server running but quiescent (ie. no logged on users) and repeats continually:

strace -tt -p 18873 -f -e trace=file --

[pid 18808] 17:35:23.002049 openat(AT_FDCWD, "/sys/fs/cgroup/memory/system.slice/system-minecraft.slice/[email protected]/memory.limit_in_bytes", O_RDONLY) = 123
[pid 18808] 17:35:23.002216 openat(AT_FDCWD, "/sys/fs/cgroup/memory/system.slice/system-minecraft.slice/[email protected]/memory.stat", O_RDONLY) = 123
[pid 18809] 17:35:23.091314 openat(AT_FDCWD, "/sys/fs/cgroup/memory/system.slice/system-minecraft.slice/[email protected]/memory.limit_in_bytes", O_RDONLY) = 123
[pid 18809] 17:35:23.091597 openat(AT_FDCWD, "/sys/fs/cgroup/memory/system.slice/system-minecraft.slice/[email protected]/memory.stat", O_RDONLY) = 123
[pid 19040] 17:35:23.149896 lstat("./world_the_end/DIM1/region/c.-6.0.mcc", 0x7f117d7fe260) = -1 ENOENT (No such file or directory)
[pid 19040] 17:35:23.156798 lstat("./world_the_end/DIM1/region/c.-6.1.mcc", 0x7f117d7fe260) = -1 ENOENT (No such file or directory)
[pid 18873] 17:35:23.499170 lstat("./world_the_end/DIM1/region/c.-6.0.mcc", 0x7f117f5fc260) = -1 ENOENT (No such file or directory)
[pid 18873] 17:35:23.506497 lstat("./world_the_end/DIM1/region/c.-6.1.mcc", 0x7f117f5fc260) = -1 ENOENT (No such file or directory)
[pid 19040] 17:35:23.848782 lstat("./world_the_end/DIM1/region/c.-6.0.mcc", 0x7f117d7fe260) = -1 ENOENT (No such file or directory)
[pid 19040] 17:35:23.855749 lstat("./world_the_end/DIM1/region/c.-6.1.mcc", 0x7f117d7fe260) = -1 ENOENT (No such file or directory)
[pid 18873] 17:35:24.199713 lstat("./world_the_end/DIM1/region/c.-6.0.mcc", 0x7f117f5fc260) = -1 ENOENT (No such file or directory)
[pid 18873] 17:35:24.210546 lstat("./world_the_end/DIM1/region/c.-6.1.mcc", 0x7f117f5fc260) = -1 ENOENT (No such file or directory)
[pid 19040] 17:35:24.548752 lstat("./world_the_end/DIM1/region/c.-6.0.mcc", 0x7f117d7fe260) = -1 ENOENT (No such file or directory)
[pid 19040] 17:35:24.555750 lstat("./world_the_end/DIM1/region/c.-6.1.mcc", 0x7f117d7fe260) = -1 ENOENT (No such file or directory)
[pid 18873] 17:35:24.898879 lstat("./world_the_end/DIM1/region/c.-6.0.mcc", 0x7f117f5fc260) = -1 ENOENT (No such file or directory)
[pid 18873] 17:35:24.905806 lstat("./world_the_end/DIM1/region/c.-6.1.mcc", 0x7f117f5fc260) = -1 ENOENT (No such file or directory)