svn commit: r316938 - head/sbin/savecore

[Julian Elischer]

On 15/4/17 4:14 am, Slawa Olhovchenkov wrote:
> On Fri, Apr 14, 2017 at 01:49:51PM -0600, Alan Somers wrote:
>
>> On Fri, Apr 14, 2017 at 1:41 PM, Ngie Cooper <ngie at freebsd.org> wrote:
>>> Author: ngie
>>> Date: Fri Apr 14 19:41:48 2017
>>> New Revision: 316938
>>> URL: https://svnweb.freebsd.org/changeset/base/316938
>>>
>>> Log:
>>>    savecore: fix space calculation with respect to `minfree` in check_space(..)
>>>
>>>    - Use strtoll(3) instead of atoi(3), because atoi(3) limits the
>>>      representable data to INT_MAX. Check the values received from
>>>      strtoll(3), trimming trailing whitespace off the end to maintain
>>>      POLA.
>>>    - Use `KiB` instead of `kB` when describing free space, total space,
>>>      etc. I am now fully aware of `KiB` being the IEC standard for 1024
>>>      bytes and `kB` being the IEC standard for 1000 bytes.
>>>    - Store available number of KiB in `available` so it can be more
>>>      easily queried and compared to ensure that there are enough KiB to
>>>      store the dump image on disk.
>>>    - Print out the reserved space on disk, per `minfree`, so end-users
>>>      can troubleshoot why check_space(..) is reporting that there isn't
>>>      enough free space.
>>>
>>>    MFC after:    7 weeks
>>>    Reviewed by:  Anton Rang <rang at acm.com> (earlier diff), cem (earlier diff)
>>>    Tested with:  positive/negative cases (see review); make tinderbox
>>>    Sponsored by: Dell EMC Isilon
>>>    Differential Revision:        D10379
>> The free space calculation is still uselessly conservative, because it
>> doesn't account for the fact that core dumps will always be either
>> spare or compressed.  The result is that savecore will frequently
>> refuse to save corefiles even when there's plenty of space.  I
>> proposed removing the space check altogether in
>> https://reviews.freebsd.org/D2587.  However, I agreed to wait until
>> after the compressed core dump feature was merged, because then mostly
>> accurate space checks will be possible.  AFAIK the compressed core
>> dump feature still hasn't been finished.
> Is posible (in the future) to use multiple swaps (on multiple disks)
> for save core dumps?

We ($JOB) already have code that does this.
dumpon can be called multiple times and the coredump code will span 
multiple devices,