Copy( cp) Performance On ACFS

(Doc ID 1450794.1)

Last updated on MAY 04, 2017

Applies to:

Oracle Server - Enterprise Edition - Version 11.2.0.0. and later
Information in this document applies to any platform.

Symptoms

You have started copy command 'cp' from one node on ACFS and it was interrupted when you run command 'ls' on same directory from another node.cp command will hang and cp process will shoot up and be top process.

you will see high time spend on 'getdents' operation,if you do strace or truss on that ls process .

OSwatcher Top output from the node where cp command was running::

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND          
 
 25061 root      18   0 69636  724  616 R 101.2  0.0   0:11.79 cp           <<<<<<<<<<<<<<<<<   
 
 13498 root      RT   0  304m 142m  59m S  1.0  0.1   1:14.05 ologgerd        
 
 25170 root      18   0 59068  884  612 S  1.0  0.0   0:00.01 iostat          
 
     1 root      15   0 10344  688  572 S  0.0  0.0   0:03.70 init    


strace output on 'ls' command on other node::

 


 14:32:02.213791 close(3)                = 0
 14:32:02.213815 munmap(0x2aeb8308f000, 4096) = 0
 14:32:02.213841 open("/backup", O_RDONLY|O_NONBLOCK|O_DIRECTORY) = 3
 14:32:02.213873 fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
 14:32:02.213900 fcntl(3, F_SETFD, FD_CLOEXEC) = 0
 14:32:02.213921 getdents(3, /* 5 entries */, 4096) = 136 <<<<<<<<<<<<<
 14:32:02.213965 getdents(3, /* 0 entries */, 4096) = 0
 14:32:02.213986 close(3)                = 0
 14:32:02.214014 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0),
 ...}) = 0

Cause

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