我有一个简单的基于 ubuntu 15.10 的 docker 镜像，它只运行 bash。该镜像大约 1.2gb。它启动非常快，但是当我尝试在退出后删除容器时，总是需要大约 6 秒的时间：
$ time ( echo "exit" | sudo docker run -i media-toolkit )
real 0m0.626s
user 0m0.028s
sys 0m0.004s
$ sudo docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
64d87dfddd60 media-toolkit "/bin/sh -c bash" 11 seconds ago Exited (0) 11 seconds ago backstabbing_darwin
$ time sudo docker rm 64d87dfddd60
64d87dfddd60
real 0m5.860s
user 0m0.028s
sys 0m0.004s
我无法找到可以加快速度的命令行组合。容器已停止，并且没有与主机进行网络或套接字通信。它有一个挂载，在上面的示例中甚至没有实际挂载。我查看了源代码这里但我看不出移除容器需要花费大量时间的任何明显原因。发生了什么？
更新 1
这是 docker rm 命令尾部的相关 strace 输出：
write(3, "DELETE /v1.21/containers/e9c8084"..., 119) = 119
epoll_wait(4, {{EPOLLOUT, {u32=836052264, u64=140506396173608}}}, 128, 0) = 1
epoll_wait(4, {{EPOLLIN|EPOLLOUT, {u32=836052264, u64=140506396173608}}}, 128, -1) = 1
clock_gettime(CLOCK_MONOTONIC, {3747600, 756232919}) = 0
futex(0x1caa060, FUTEX_WAKE, 1) = 1
read(3, "HTTP/1.1 204 No Content\r\nServer:"..., 4096) = 94
read(3, 0xc208516000, 4096) = -1 EAGAIN (Resource temporarily unavailable)
write(1, "e9c8084400e2\n", 13e9c8084400e2
) = 13
exit_group(0) = ?
+
++ exited with 0 +++
它挂在其中一条线路上epoll_wait，大概是在等待守护进程的响应。这是守护进程在收到 DELETE 命令后正在做的事情：
[pid 13026] 14:51:56.377411 <... read resumed> "DELETE /v1.21/containers/d267f0e"..., 4096) = 119
[pid 13026] 14:51:56.378089 write(2, "time=\"2016-01-21T14:51:56.377925"..., 99) = 99
[pid 13026] 14:51:56.378738 access("/var/lib/docker/linkgraph.db-journal", F_OK) = -1 ENOENT (No such file or directory)
[pid 13026] 14:51:56.379913 fcntl(12, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 0
[pid 13026] 14:51:56.379987 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:56.380846 close(15) = 0
[pid 13026] 14:51:56.381531 close(15) = 0
[pid 13026] 14:51:56.382176 access("/var/lib/docker/linkgraph.db-journal", F_OK) = -1 ENOENT (No such file or directory)
[pid 13026] 14:51:56.382241 fstat(9, {st_mode=S_IFREG|0644, st_size=69632, ...}) = 0
[pid 13026] 14:51:56.383715 stat("/var/lib/docker/linkgraph.db", {st_mode=S_IFREG|0644, st_size=69632, ...}) = 0
[pid 13026] 14:51:56.383814 open("/var/lib/docker/linkgraph.db-journal", O_RDWR|O_CREAT|O_CLOEXEC, 0644) = 15
[pid 13026] 14:51:56.383933 fstat(15, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
[pid 13026] 14:51:56.384000 geteuid() = 0
[pid 13026] 14:51:56.384073 fchown(15, 0, 0) = 0
[pid 13026] 14:51:56.384143 fstat(15, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
[pid 13026] 14:51:56.384206 lseek(15, 0, SEEK_SET) = 0
[pid 13026] 14:51:56.384264 write(15, "\0\0\0\0\0\0\0\0\0\0\0\0O\233R\327\0\0\0D\0\0\2\0\0\0\4\0\0\0\0\0"..., 512) = 512
[pid 13026] 14:51:56.384342 lseek(15, 512, SEEK_SET) = 512
[pid 13026] 14:51:56.384414 write(15, "\0\0\0\5", 4) = 4
[pid 13026] 14:51:56.384502 lseek(15, 516, SEEK_SET) = 516
[pid 13026] 14:51:56.384564 write(15, "\n\1\244\0\2\1\227\7\1\227\3\353\3\353\3>\3>\3>\3>\3\351\3\351\3\351\3\351\3\351"..., 1024) = 1024
[pid 13026] 14:51:56.384638 lseek(15, 1540, SEEK_SET) = 1540
[pid 13026] 14:51:56.384717 write(15, "O\233S\331", 4) = 4
[pid 13026] 14:51:56.384786 lseek(15, 1544, SEEK_SET) = 1544
[pid 13026] 14:51:56.384814 write(15, "\0\0\0\4", 4) = 4
[pid 13026] 14:51:56.384893 lseek(15, 1548, SEEK_SET) = 1548
[pid 13026] 14:51:56.384955 write(15, "\r\0\230\0\2\0\220\0\0\220\3\252\3R\2\375\2\250\3\253\3\253\3\253\3\253\3\253\3\253\3\316"..., 1024) = 1024
[pid 13026] 14:51:56.385030 lseek(15, 2572, SEEK_SET) = 2572
[pid 13026] 14:51:56.385058 write(15, "O\233T9", 4) = 4
[pid 13026] 14:51:56.385133 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:56.385713 read(9, "\r\0\177\0\2\0z\0\0z\3\273\3v\0031\2\354\3\273\3\273\3\273\3\273\3\273\3\273\3\273"..., 1024) = 1024
[pid 13026] 14:51:56.385780 lseek(15, 2576, SEEK_SET) = 2576
[pid 13026] 14:51:56.387179 lseek(15, 3612, SEEK_SET) = 3612
[pid 13026] 14:51:56.387252 write(15, "\r\0\177\0\2\0z\0\0z\3\273\3v\0031\2\354\3\273\3\273\3\273\3\273\3\273\3\273\3\273"..., 1024) = 1024
[pid 13026] 14:51:56.387298 lseek(15, 4636, SEEK_SET) = 4636
[pid 13026] 14:51:56.387365 write(15, "O\233S\335", 4) = 4
[pid 13026] 14:51:56.387443 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:56.388054 write(15, "\0\0\0\1", 4) = 4
[pid 13026] 14:51:56.388125 lseek(15, 4644, SEEK_SET) = 4644
[pid 13026] 14:51:56.392231 open("/var/lib/docker", O_RDONLY|O_CLOEXEC) = 17
[pid 13026] 14:51:56.392303 fsync(17) = 0
[pid 13026] 14:51:56.392332 close(17) = 0
[pid 13026] 14:51:56.392392 lseek(15, 0, SEEK_SET) = 0
[pid 13026] 14:51:56.392449 write(15, "\331\325\5\371 \241c\327\0\0\0\5", 12) = 12
[pid 13026] 14:51:56.392521 fsync(15) = 0
[pid 13026] 14:51:56.394289 lseek(9, 0, SEEK_SET) = 0
[pid 13026] 14:51:56.394351 write(9, "SQLite format 3\0\4\0\1\1\0@ \0\0\2\257\0\0\0D"..., 1024) = 1024
[pid 13026] 14:51:56.394423 lseek(9, 1024, SEEK_SET) = 1024
[pid 13026] 14:51:56.394483 write(9, "\r\0\177\0\1\0z\0\0z\3\273\3v\0031\2\354\3\273\3\273\3\273\3\273\3\273\3\273\3\273"..., 1024) = 1024
[pid 13026] 14:51:56.394548 lseek(9, 2048, SEEK_SET) = 2048
[pid 13026] 14:51:56.394606 write(9, "\n\0r\0\1\0m\0\0m\3\272\3\272\3t\3t\3\272\3\272\3\272\3\272\3\272\3\272\3\272"..., 1024) = 1024
[pid 13026] 14:51:56.394673 lseek(9, 3072, SEEK_SET) = 3072
[pid 13026] 14:51:56.394730 write(9, "\r\0\230\0\1\0\220\0\0\220\3\252\3R\2\375\2\250\3\253\3\253\3\253\3\253\3\253\3\253\3\316"..., 1024) = 1024
[pid 13026] 14:51:56.394799 lseek(9, 4096, SEEK_SET) = 4096
[pid 13026] 14:51:56.394857 write(9, "\n\1\244\0\1\1\227\7\1\227\3\353\3\353\3>\3>\3>\3>\3\351\3\351\3\351\3\351\3\351"..., 1024) = 1024
[pid 13026] 14:51:56.394925 fsync(9) = 0
[pid 13026] 14:51:56.396797 close(15) = 0
[pid 13026] 14:51:56.396861 unlink("/var/lib/docker/linkgraph.db-journal") = 0
[pid 13026] 14:51:56.396966 fcntl(9, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741826, len=510}) = 0
[pid 13026] 14:51:56.397047 fcntl(9, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=1073741824, len=2}) = 0
[pid 13026] 14:51:56.397081 fcntl(9, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 0
[pid 13026] 14:51:56.397150 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:56.397821 semget(0xd4deb33, 1, IPC_CREAT|IPC_EXCL|0600) = 147292178
[pid 13026] 14:51:56.397933 semctl(147292178, 0, SETVAL, 0x1) = 0
[pid 13026] 14:51:56.398467 semctl(147292178, 0, GETVAL, 0x7f1d2fb9a3c7) = 2
[pid 13026] 14:51:56.400115 ioctl(5, DM_DEV_SUSPEND, 0x7f1d24042870) = 0
[pid 13026] 14:51:56.405698 semctl(147292178, 0, IPC_RMID, 0) = 0
[pid 13026] 14:51:56.405777 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:56.406024 ioctl(5, DM_DEV_STATUS, 0x7f1d24046880) = 0
[pid 13026] 14:51:56.406094 open("/dev/mapper/docker-202:1-790981-d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d", O_RDWR|O_CLOEXEC) = 15
[pid 13026] 14:51:56.406164 ioctl(15, BLKGETSIZE64, 107374182400) = 0
[pid 13026] 14:51:59.441157 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.451108 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.451240 close(15) = 0
[pid 13026] 14:51:59.451815 ioctl(5, DM_DEV_STATUS, 0x7f1d2404a890) = 0
[pid 13026] 14:51:59.451938 open("/dev/urandom", O_RDONLY) = 15
[pid 13026] 14:51:59.452049 read(15, "P\227", 2) = 2
[pid 13026] 14:51:59.452149 semget(0xd4d9750, 1, IPC_CREAT|IPC_EXCL|0600) = 147324946
[pid 13026] 14:51:59.452247 semctl(147324946, 0, SETVAL, 0x1) = 0
[pid 13026] 14:51:59.452505 semctl(147324946, 0, GETVAL, 0x7f1d2fb9a42a) = 1
[pid 13026] 14:51:59.452815 semop(147324946, {{0, 1, 0}}, 1) = 0
[pid 13026] 14:51:59.453310 semctl(147324946, 0, GETVAL, 0x7f1d2fb9a3c7) = 2
[pid 13026] 14:51:59.454544 semctl(147324946, 0, GETVAL, 0x800) = 2
[pid 13026] 14:51:59.454609 semop(147324946, {{0, -1, IPC_NOWAIT}}, 1) = 0
[pid 13026] 14:51:59.457329 semctl(147324946, 0, IPC_RMID, 0) = 0
[pid 13026] 14:51:59.457396 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.457710 open("/var/lib/docker/devicemapper/metadata/.tmp717030394", O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0600) = 15
[pid 13026] 14:51:59.457827 write(15, "{\"open_transaction_id\":1570,\"dev"..., 125) = 125
[pid 13026] 14:51:59.462635 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.462820 rename("/var/lib/docker/devicemapper/metadata/.tmp717030394", "/var/lib/docker/devicemapper/metadata/transaction-metadata") = 0
[pid 13026] 14:51:59.462955 stat("/dev/mapper/docker-202:1-790981-pool", {st_mode=S_IFBLK|0660, st_rdev=makedev(253, 0), ...}) = 0
[pid 13026] 14:51:59.463032 stat("/dev/mapper/docker-202:1-790981-pool", {st_mode=S_IFBLK|0660, st_rdev=makedev(253, 0), ...}) = 0
[pid 13026] 14:51:59.468869 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.472111 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.472745 open("/dev/urandom", O_RDONLY) = 15
[pid 13026] 14:51:59.473273 semctl(147357714, 0, GETVAL, 0x7f1d2fb9a42a) = 1
[pid 13026] 14:51:59.473338 close(15) = 0
[pid 13026] 14:51:59.473400 semop(147357714, {{0, 1, 0}}, 1) = 0
[pid 13026] 14:51:59.474993 ioctl(5, DM_DEV_SUSPEND, 0x7f1d2405e8e0) = 0
[pid 13026] 14:51:59.480219 semctl(147357714, 0, IPC_RMID, 0) = 0
[pid 13026] 14:51:59.480290 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:51:59.480594 ioctl(5, DM_DEV_STATUS, 0x7f1d240628f0) = 0
[pid 13026] 14:51:59.480671 open("/dev/mapper/docker-202:1-790981-d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d-init", O_RDWR|O_CLOEXEC) = 15
[pid 13026] 14:51:59.480752 ioctl(15, BLKGETSIZE64, 107374182400) = 0
[pid 13026] 14:52:02.489043 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:52:02.506827 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:52:02.507470 ioctl(5, DM_DEV_STATUS, 0x7f1d24066900) = 0
[pid 13026] 14:52:02.507567 open("/dev/urandom", O_RDONLY) = 15
[pid 13026] 14:52:02.507704 read(15, "c\236", 2) = 2
[pid 13026] 14:52:02.507775 semget(0xd4d9e63, 1, IPC_CREAT|IPC_EXCL|0600) = 147390482
[pid 13026] 14:52:02.507854 semctl(147390482, 0, SETVAL, 0x1) = 0
[pid 13026] 14:52:02.507919 semctl(147390482, 0, GETVAL, 0x7f1d2fb9a42a) = 1
[pid 13026] 14:52:02.507987 close(15) = 0
[pid 13026] 14:52:02.508049 semop(147390482, {{0, 1, 0}}, 1) = 0
[pid 13026] 14:52:02.508114 semctl(147390482, 0, GETVAL, 0x7f1d2fb9a3c7) = 2
[pid 13026] 14:52:03.262530 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:52:03.262894 semget(0xd4d9e63, 1, 0) = 147390482
[pid 13026] 14:52:03.262994 semctl(147390482, 0, GETVAL, 0x800) = 1
[pid 13026] 14:52:03.263027 semop(147390482, {{0, -1, IPC_NOWAIT}}, 1) = 0
[pid 13026] 14:52:03.263076 semop(147390482, {{0, 0, 0}}, 1) = 0
[pid 13026] 14:52:03.263107 semctl(147390482, 0, IPC_RMID, 0) = 0
[pid 13026] 14:52:03.263221 stat("/dev/mapper/docker-202:1-790981-d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d-init", 0x7f1d077fcbc0) = -1 ENOENT (No such file or directory)
[pid 13026] 14:52:03.263330 open("/var/lib/docker/devicemapper/metadata/.tmp662028049", O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0600) = 15
[pid 13026] 14:52:03.263537 write(15, "{\"open_transaction_id\":1571,\"dev"..., 130) = 130
[pid 13026] 14:52:03.266148 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:52:03.266316 rename("/var/lib/docker/devicemapper/metadata/.tmp662028049", "/var/lib/docker/devicemapper/metadata/transaction-metadata") = 0
[pid 13026] 14:52:03.266458 stat("/dev/mapper/docker-202:1-790981-pool", {st_mode=S_IFBLK|0660, st_rdev=makedev(253, 0), ...}) = 0
[pid 13026] 14:52:03.266533 stat("/dev/mapper/docker-202:1-790981-pool", {st_mode=S_IFBLK|0660, st_rdev=makedev(253, 0), ...}) = 0
[pid 13026] 14:52:03.273534 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:52:03.273796 stat("/dev/mapper/docker-202:1-790981-pool", {st_mode=S_IFBLK|0660, st_rdev=makedev(253, 0), ...}) = 0
[pid 13026] 14:52:03.273904 stat("/dev/mapper/docker-202:1-790981-pool", {st_mode=S_IFBLK|0660, st_rdev=makedev(253, 0), ...}) = 0
[pid 13026] 14:52:03.276718 futex(0x1caa060, FUTEX_WAKE, 1) = 1
[pid 13026] 14:52:03.276979 rmdir("/var/lib/docker/devicemapper/mnt/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d-init") = 0
[pid 13026] 14:52:03.277084 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d") = -1 EISDIR (Is a directory)
[pid 13026] 14:52:03.277170 rmdir("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d") = -1 ENOTEMPTY (Directory not empty)
[pid 13026] 14:52:03.277289 lstat("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d", {st_mode=S_IFDIR|0700, st_size=4096, ...}) = 0
[pid 13026] 14:52:03.277377 open("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d", O_RDONLY|O_CLOEXEC) = 15
[pid 13026] 14:52:03.277473 getdents64(15, /* 11 entries */, 4096) = 408
[pid 13026] 14:52:03.277581 getdents64(15, /* 0 entries */, 4096) = 0
[pid 13026] 14:52:03.277644 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d-json.log") = 0
[pid 13026] 14:52:03.277742 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/mqueue") = -1 EISDIR (Is a directory)
[pid 13026] 14:52:03.277811 rmdir("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/mqueue") = 0
[pid 13026] 14:52:03.277909 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/hostname") = 0
[pid 13026] 14:52:03.278008 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/config.json") = 0
[pid 13026] 14:52:03.278095 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/resolv.conf.hash") = 0
[pid 13026] 14:52:03.278171 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/shm") = -1 EISDIR (Is a directory)
[pid 13026] 14:52:03.278239 rmdir("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/shm") = 0
[pid 13026] 14:52:03.278334 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/hosts") = 0
[pid 13026] 14:52:03.278421 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/hostconfig.json") = 0
[pid 13026] 14:52:03.278503 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d/resolv.conf") = 0
[pid 13026] 14:52:03.278572 getdents64(15, /* 0 entries */, 4096) = 0
[pid 13026] 14:52:03.278665 close(15) = 0
[pid 13026] 14:52:03.278724 unlink("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d") = -1 EISDIR (Is a directory)
[pid 13026] 14:52:03.278790 rmdir("/var/lib/docker/containers/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d") = 0
[pid 13026] 14:52:03.278867 unlink("/var/run/docker/execdriver/native/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d") = -1 ENOENT (No such file or directory)
[pid 13026] 14:52:03.278935 rmdir("/var/run/docker/execdriver/native/d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d") = -1 ENOENT (No such file or directory)
[pid 13026] 14:52:03.279060 clock_gettime(CLOCK_REALTIME, {1453405923, 279086865}) = 0
[pid 13026] 14:52:03.279190 clock_gettime(CLOCK_REALTIME, {1453405923, 279204411}) = 0
并不是说我删除了很多行以<... x resumed>适应问题主体限制。如果这些行很重要，请告诉我。
更新 2
看起来延迟发生在如下两个调用中，每个调用大约耗时 3 秒：
[pid 13026] 14:51:56.406094 open("/dev/mapper/docker-202:1-790981-d267f0e99e38c261ca9b35109591e278c99b559d280bd30b6f741e249769f33d", O_RDWR|O_CLOEXEC) = 15
[pid 13026] 14:51:56.406164 ioctl(15, BLKGETSIZE64, 107374182400) = 0
[pid 13026] 14:51:56.406250 ioctl(15, BLKDISCARD, {0, 0} <unfinished ...>
[pid 13026] 14:51:59.440956 <... ioctl resumed> ) = 0
有什么方法可以加速这个操作或者消除这个操作吗？
更新 3
我忘记包含我的 docker 版本：
$ docker --version
Docker version 1.9.1, build a34a1d5/1.9.1
答案1
好吧，事实证明解释相当简单。清理时间缓慢似乎是使用 Amazon EBS 上的循环设备运行 docker 设备映射器的副作用。为了可能有用，我开发了一种解决方法，使删除不会阻止启动映像的进程。在运行映像的 bash 脚本的末尾，我添加了以下内容（其中是$IMAGE正在使用的 docker 映像的名称）：
nohup ionice -c 3 nice -n 19 \
docker rm $( docker ps -aq -f "status=exited" -f "ancestor=$IMAGE" ) \
0</dev/null &>/dev/null &
这将清理来自同一映像的所有已退出的容器，因此即使它一次运行失败，它也会在下一次传递时获取遗留的容器。我认为这种方法对于补偿由循环设备引起的清理问题（如果有的话）会很有效，但如果您使用 EBS，它就没有多大帮助。原因是 EBS 操作使用来自映像配额但难以直接看到的“隐藏”资源。换句话说，虚拟机管理程序正在为您做一些工作，由于它不在操作系统的调度系统内，因此它无法尊重nice或ionice。最终结果是该过程将立即退出，容器将在接下来的 6 秒左右被清理，但在此期间性能仍然会很低迷。
更好的解决方案是连接临时存储设备并按照说明操作这里，假设你使用的是 Amazon Linux 或类似系统，并且在 /dev/xvdb 有一个 30GB 的临时卷：
$ sudo service docker stop
$ sudo rm -rf /var/lib/docker
$ sudo umount /dev/xvdb
$ sudo pvcreate /dev/xvdb
$ sudo vgcreate vg-docker /dev/xvdb
$ sudo lvcreate -L 20G -n data vg-docker
$ sudo lvcreate -L 4G -n metadata vg-docker
$ echo 'DOCKER_STORAGE_OPTIONS="--storage-opt dm.datadev=/dev/vg-docker/data --storage-opt dm.metadatadev=/dev/vg-docker/metadata --storage-opt dm.use_deferred_removal=true --storage-opt dm.use_deferred_deletion=true"' \
> sudo tee /etc/sysconfig/docker-storage
$ sudo service docker start
$ sudo docker info
Containers: 0
Images: 2
Server Version: 1.9.1
Storage Driver: devicemapper
Pool Name: docker-202:1-263721-pool
Pool Blocksize: 65.54 kB
Base Device Size: 107.4 GB
Backing Filesystem:
Data file: /dev/vg-docker/data
Metadata file: /dev/vg-docker/metadata
Data Space Used: 58.39 MB
Data Space Total: 21.47 GB
Data Space Available: 21.42 GB
Metadata Space Used: 426 kB
Metadata Space Total: 4.295 GB
Metadata Space Available: 4.295 GB
Udev Sync Supported: true
Deferred Removal Enabled: true
Deferred Deletion Enabled: true
Deferred Deleted Device Count: 0
...