[ OK ] Finished Remount Root and Kernel File Systems.
Starting Load/Save Random Seed...
[ 19.905402] systemd-journald[1486]: Journal effective settings seal=no compress=yes compress_threshold_bytes=512B
[ 19.919293] systemd-journald[1486]: Fixed min_use=1.9M max_use=9.8M max_size=1.2M min_size=512.0K keep_free=4.9M n_max_files=100
[ 19.927851] systemd[1]: systemd-sysusers.service: ConditionNeedsUpdate=/etc succeeded.
[ 19.932942] systemd-journald[1486]: Reserving 2240 entries in hash table.
[ 19.949073] systemd-journald[1486]: Vacuuming...
[ 19.957832] systemd-journald[1486]: Vacuuming done, freed 0B of archived journals from /run/log/journal/e1e5e8c53feef773ecb2dd4445922f16.
[ 19.960858] systemd[1]: Failed to read pids.max attribute of cgroup root, ignoring: No such file or directory
[ 19.972072] systemd-journald[1486]: Flushing /dev/kmsg...
[ 20.007901] systemd[1]: systemd-sysusers.service: Passing 0 fds to service
[ 20.023398] systemd[1]: systemd-sysusers.service: About to execute: /usr/bin/systemd-sysusers
[ 20.071506] systemd[1]: systemd-sysusers.service: Forked /usr/bin/systemd-sysusers as 1643
[ 20.112674] systemd[1]: systemd-sysusers.service: Changed dead -> start
[ 20.125614] systemd[1]: Starting Create System Users...
Starting Create System Users...
[ 20.156246] systemd[1]: Received SIGCHLD from PID 1488 (systemd-modules).
[ 20.172570] systemd[1]: Child 1488 (systemd-modules) died (code=exited, status=0/SUCCESS)
[ 20.207556] systemd[1]: systemd-modules-load.service: Failed to read oom_kill field of memory.events cgroup attribute: No such file or directory
[ 20.235760] systemd[1]: systemd-modules-load.service: Child 1488 belongs to systemd-modules-load.service.
[ 20.259301] systemd[1]: systemd-modules-load.service: Main process exited, code=exited, status=0/SUCCESS
[ 20.272363] systemd[1]: systemd-modules-load.service: Changed start -> exited
[ 20.280484] systemd-journald[1486]: systemd-journald running as PID 1486 for the system.
[ 20.280536] systemd[1]: systemd-modules-load.service: Job 21 systemd-modules-load.service/start finished, result=done
[ 20.290483] systemd-journald[1486]: Sent READY=1 notification.
[ 20.300302] systemd[1]: Finished Load Kernel Modules.
[ OK ] Finished Load Kernel Modules.
[ 20.324133] systemd[1]: systemd-journald.service: Got notification message from PID 1486 (READY=1, STATUS=Processing requests...)
[ 20.336268] systemd[1]: systemd-journald.service: Changed start -> running
[ 20.343416] systemd[1]: systemd-journald.service: Job 11 systemd-journald.service/start finished, result=done
[ 20.353666] systemd[1]: Started Journal Service.
[ OK ] Started Journal Service.
[ 20.371241] systemd[1]: systemd-journald-dev-log.socket: Changed listening -> running
[ OK ] Finished Load/Save Random Seed.
Mounting Kernel Configuration File System...
Starting Flush Journal to Persistent Storage...
Starting Apply Kernel Variables...
[ *** ] (6 of 7) A start job is running for…ersistent Storage (26s / 1min 31s)
[ 201.783150] nfs: server 10.10.20.2 not responding, still trying
[ 226.359118] nfs: server 10.10.20.2 not responding, still trying
[ 255.031099] nfs: server 10.10.20.2 not responding, timed out
[ 435.255106] nfs: server 10.10.20.2 not responding, timed out
[ 441.399099] nfs: server 10.10.20.2 not responding, timed out
[ 615.479112] nfs: server 10.10.20.2 not responding, timed out
[ 626.743092] nfs: server 10.10.20.2 not responding, timed out
[ 795.703192] nfs: server 10.10.20.2 not responding, timed out
[ 812.087098] nfs: server 10.10.20.2 not responding, timed out
U-Boot参数：
dhcp;
nfs ${kernel_addr} ${serverip}:/export/boot/Image;
nfs ${fdt_addr} ${serverip}:/export/boot/armada.dtb;
set bootargs "$console root=/dev/nfs rw rootfstype=nfs nfsrootdebug ip=dhcp nfsroot=${serverip}:/export,nolock,vers=4,tcp rootwait earlyprint=p1011,0x7ff80000 debug";
booti ${kernel_addr} - ${fdt_addr};
“/etc/exports”：
/export *(rw,nohide,insecure,no_subtree_check,async,no_root_squash)
答案1
进入启动顺序的这一部分后，Linux 会尝试重新挂载其文件系统。它目前处于挂起状态，因为即使它可以访问 nfs 文件系统，但在使用 fstab 重新挂载后，它将失去对 nfs 共享的访问权限。要使 nfs 正常工作，必须在 fstab 中添加根目录条目以及防火墙，以使 nfs 能够通过防火墙进行通信。