我已经从这个site下载并安装了静态链接的docker 1.6.1,并在RHEL 7.1上运行它：
@H_301_5@[root@localhost bin]# ./docker -d
WARN[0000] Udev sync is not supported. This will lead to unexpected behavior,data loss and errors
INFO[0000] +job init_networkdriver()
INFO[0000] +job serveapi(unix:///var/run/docker.sock)
INFO[0000] Listening for HTTP on unix (/var/run/docker.sock)
INFO[0000] -job init_networkdriver() = OK (0)
INFO[0000] Loading containers: start.
INFO[0000] Loading containers: done.
INFO[0000] docker daemon: 1.6.1 97cd073; execdriver: native-0.2; graphdriver: devicemapper
INFO[0000] +job acceptconnections()
INFO[0000] -job acceptconnections() = OK (0)
INFO[0000] Daemon has completed initialization
我可以看到有一个警告：“不支持Udev同步.这将导致意外行为,数据丢失和错误”,并且在检查docker源代码后,我发现警告日志来自deviceset.go：
@H_301_5@func (devices *DeviceSet) initDevmapper(doInit bool) error {
......
// https://github.com/docker/docker/issues/4036
if supported := devicemapper.UdevSetSyncSupport(true); !supported {
log.Warnf("Udev sync is not supported. This will lead to unexpected behavior,data loss and errors")
}
log.Debugf("devicemapper: udev sync support: %v",devicemapper.UdevSyncSupported())
......
}
devicemapper.UdevSetSyncSupport是这样的：
@H_301_5@// UdevSyncSupported returns whether device-mapper is able to sync with udev
//
// This is essential otherwise race conditions can arise where both udev and
// device-mapper attempt to create and destroy devices.
func UdevSyncSupported() bool {
return DmUdevGetSyncSupport() != 0
}
// UdevSetSyncSupport allows setting whether the udev sync should be enabled.
// The return bool indicates the state of whether the sync is enabled.
func UdevSetSyncSupport(enable bool) bool {
if enable {
DmUdevSetSyncSupport(1)
} else {
DmUdevSetSyncSupport(0)
}
return UdevSyncSupported()
}
我可以看到原因是启用udev同步失败.如何成功启用udev同步？
更新：
检查dm_udev_set_sync_support的反汇编代码后：
(gdb) disassemble dm_udev_set_sync_support
Dump of assembler code for function dm_udev_set_sync_support:
=> 0x0000000000a3e4e0 <+0>: repz retq
End of assembler dump.
最佳答案
我不能重现你的问题;我得到以下内容：
@H_301_5@
(gdb) disassemble dm_udev_set_sync_support
Dump of assembler code for function dm_udev_set_sync_support@plt:
0x0000000000403420 <+0>: jmpq *0xda8c92(%rip) # 0x11ac0b8 403426 <+6>: pushq $0x14
0x000000000040342b <+11>: jmpq 0x4032d0
帮自己一个忙：忽略docker.io所做的构建,直接从RHEL获取Docker.它可以在Extras频道中找到.虽然它通常比上游版本落后几周(例如1.6而不是1.7),但它也经过了充分测试并保证实际工作.
