RE: some concern about the fix of " tail: consistently output all data for truncated files"

[Lian, George (Nokia - CN/Hangzhou)]

Hi, Berny, 

the syslog file is not being rotated, so we have no option with 
"ma-unchanged-stats".
The issue is occurred while a read 's size less than the stat.st_size, and 
there has no truncated occurred.
But tail treat it as truncate case and print all the data from the begin.

We has an automatic case used as "tail -F "file" > "period_log_file",  which we 
need catch about one hour of syslog to another file.
But with this pseudo-truncate issue, this command will eat all disk file of a 
host.


Best Regards,
George

-----Original Message-----
From: Bernhard Voelker [mailto:address@hidden] 
Sent: Wednesday, November 09, 2016 5:25 AM
To: Lian, George (Nokia - CN/Hangzhou) <address@hidden>; Pádraig Brady 
<address@hidden>; address@hidden
Cc: Zhang, Bingxuan (Nokia - CN/Hangzhou) <address@hidden>; Li, Deqian (Nokia - 
CN/Hangzhou) <address@hidden>; Zizka, Jan (Nokia - CZ/Prague) <address@hidden>; 
Bao, Xiaohui (Nokia - CN/Hangzhou) <address@hidden>
Subject: Re: some concern about the fix of " tail: consistently output all data 
for truncated files"

On 11/08/2016 03:50 AM, Lian, George (Nokia - CN/Hangzhou) wrote:
> We have an issue now for tail a syslog file which stored in a network-based 
> file system.

I'm not sure, but this sounds like a case for

  N=5
  tail -F --max-unchanged-stats="$N"  "$file"

doesn't it?

Have a nice day,
Berny