Hi Theodore On Fri, Mar 19, 2021 at 8:46 PM Theodore Ts'o <tytso@xxxxxxx> wrote: > > On Thu, Mar 18, 2021 at 12:27:44PM +0530, Shashidhar Patil wrote: > > Hi Theodore, > > I forgot to include two important details , the stack trace of > > loop0 driver and sar output, which clearly nail the problem. > > The losetup with Ubuntu16.05 does not have O_DIRECT support and we > > were not aware of bypassing of journalling if > > O_DIRECT combined with preallocated file scenario. > > Which version of the kernel are you using? The use of O_DIRECT for I am using *antediluvian* ubunut 16.04 LTS as below $ uname -a Linux ubuntu 4.15.0-117-generic #118~16.04.1-Ubuntu SMP Sat Sep 5 23:35:06 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux > loop devices requires kernel and losetup support. (Also note that As per the backtrace of loop0 driver attached it does look like a problem, right ? > upstream developers really generally don't pay attention --- or > support --- distribution kernels unless they work for the company for > which you are paying $$$ for support, and Ubuntu 16.05 isn't even a $$$ again. No respite from $$ urge. $ Not good :-) $ $$$ -bash: 31163$: command not found :-) > Long-Term Support distribution.) > > My suggestion is to see if you can replicate the problem on a modern > userspace with the latest kernel. And if not, then that's an object I will try to recreate the problem with latest upstream kernel used by upstream developers. > lesson about why using a antediluvian is not a great life choice. :-) > I agree with "antediluvian is not a great life choice" but can't comment on "antediluvian is not a great choice in corporates". Thank you -Shashidhar > Cheers, > > - Ted