Re: [Moosefs-users] mfsmaster performance and hardware

[Elliot F. <efi...@gm...>]

On Mon, Aug 8, 2011 at 5:24 PM, Robert Sandilands <rsa...@ne...> wrote:
> When I run a strace() on mfsmaster on the hour I get the following:
>
> rename("changelog.1.mfs", "changelog.2.mfs") = 0
> rename("changelog.0.mfs", "changelog.1.mfs") = 0
> clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD,
> child_tidptr=0x2b571b910b80) = -1 ENOMEM (Cannot allocate memory)
> rename("metadata.mfs.back", "metadata.mfs.back.tmp") = 0
> open("metadata.mfs.back", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 11
>
> This indicates fork() is failing with an out of memory error. The system has
> 11 GB cached and 300 MB free. It only has 6 GB of swap. This indicates that
> clone() ( also known as fork() ) may be trying to test whether the whole
> process will fit into memory when cloned. Which implies that the memory
> requirement is actually double than what is commonly believed.

Just out of curiosity, what OS are you using?

Elliot