有类似的问题，但我所追求的是实时检测文件的存在。
我有2个linux box / PC。
[Linux Box 1] - ＆GT;生成名为主机（手动执行）
的文件[Linux Box 2] - ＆GT;有一个守护进程，每2秒休眠一次，检查预期的文件是否存在。如果它存在，它将执行我的ssh命令（当然会显示一条文本显示它已被执行bla bla bla）。
PERL SCRIPT：
ctr:
if (-e $file) { system ("ssh $script $host.$display"); }
sleep(2);
goto ctr;
问题 问题是，似乎我无法确定该文件是否实时存在，即使它已经存在。
BOX 1
[machine01:/home/machine01]% /MACHINE/TOOLS/perl/app/host_gen
> executed at 08/21/2015 21:40:32
BOX 2
Sleeping for 2 seconds [08/21/2015 21:40:22]
Sleeping for 2 seconds [08/21/2015 21:40:24]
Sleeping for 2 seconds [08/21/2015 21:40:26]
Sleeping for 2 seconds [08/21/2015 21:40:28]
Sleeping for 2 seconds [08/21/2015 21:40:30]
Sleeping for 2 seconds [08/21/2015 21:40:32] **<-expected execution**
Sleeping for 2 seconds [08/21/2015 21:40:34]
Sleeping for 2 seconds [08/21/2015 21:40:36]
Sleeping for 2 seconds [08/21/2015 21:40:38]
Sleeping for 2 seconds [08/21/2015 21:40:40]
Sleeping for 2 seconds [08/21/2015 21:40:42]
Sleeping for 2 seconds [08/21/2015 21:40:44]
Sleeping for 2 seconds [08/21/2015 21:40:46]
Sleeping for 2 seconds [08/21/2015 21:40:48]
Sleeping for 2 seconds [08/21/2015 21:40:50]
Sleeping for 2 seconds [08/21/2015 21:40:52]
Sleeping for 2 seconds [08/21/2015 21:40:54]
Sleeping for 2 seconds [08/21/2015 21:40:56]
Sleeping for 2 seconds [08/21/2015 21:40:58]
Sleeping for 2 seconds [08/21/2015 21:41:00]
Sleeping for 2 seconds [08/21/2015 21:41:02]
Sleeping for 2 seconds [08/21/2015 21:41:04]
Sleeping for 2 seconds [08/21/2015 21:41:06]
Sleeping for 2 seconds [08/21/2015 21:41:08]
Sleeping for 2 seconds [08/21/2015 21:41:10]
Sleeping for 2 seconds [08/21/2015 21:41:12] <- It was executed here
TYPE_AND_DISPLAY [wkss machine01.ult.ultera.omps.com:0]
TYPE [wkss] DISPLAY [machine01.ult.ultera.omps.com:0]
检测现有文件几乎需要一分钟或有时10秒钟。
这很奇怪。
你们有任何想法我怎么能实现我的目标？
提前致谢。
答案 0 :(得分：8)
Prior serverfault.com question: How can I tell if a file is on a remote filesystem with Perl?
引用该线程;
默认情况下，大多数NFS客户端将目录信息缓存60秒。
该线程中提到的解决方案：
使用noac选项在客户端上挂载NFS共享以禁用属性缓存，或者使用acdirmin = 0，acdirmax = 0来禁用目录缓存。