[LU-7765] replay-dual test 26 buggy redirection

Related — Sat, 17 Dec 2016 15:24:03 +0000

Replay dual test 26 runs dbench as "rundbench 1 -D $dbench_dir -t 100 > /dev/null 2&>1"
This typo results in attepmt to write dbench stderr to a file named 1 instead of redirecting it to descriptor 1 (/dev/null).
Since we run with mds down at the same time, that just leads to dbench hanging.

Another interesting observation is that "ps ax" hangs trying to stat this file, I did not know ps was actually trying to stat descriptors 0, 1 and 2 of a command:

stat("/proc/28723", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
open("/proc/28723/stat", O_RDONLY)      = 6
read(6, "28723 (rundbench) S 25442 29606 "..., 2048) = 359
close(6)                                = 0
open("/proc/28723/status", O_RDONLY)    = 6
read(6, "Name:\trundbench\nState:\tS (sleepi"..., 2048) = 1242
close(6)                                = 0
open("/proc/28723/cmdline", O_RDONLY)   = 6
read(6, "/bin/bash\0/home/green/git/lustre"..., 131072) = 118
read(6, "", 130954)                     = 0
close(6)                                = 0
stat("/dev/pts0", 0x7ffffd63a2e0)       = -1 ENOENT (No such file or directory)
stat("/dev/pts", {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
readlink("/proc/28723/fd/2", "/mnt/lustre2/d26.replay-dual/run"..., 127) = 41
stat("/mnt/lustre2/d26.replay-dual/run_dbench/1",

Whamcloud Community JIRA

[LU-7765] replay-dual test 26 buggy redirection