Date: Fri, 14 Apr 2017 15:48:06 -0500 From: Larry Rosenman <ler@lerctr.org> To: "Ngie Cooper (yaneurabeya)" <yaneurabeya@gmail.com> Cc: "src-committers@freebsd.org" <src-committers@freebsd.org>, Alan Somers <asomers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, Slawa Olhovchenkov <slw@zxy.spb.ru>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, Ngie Cooper <ngie@freebsd.org> Subject: Re: svn commit: r316938 - head/sbin/savecore Message-ID: <3D9A20AF-074F-494A-95FF-7A39CC964EA3@lerctr.org> In-Reply-To: <15ABDD42-E2C4-4519-B736-04A56FA8C2D0@gmail.com> References: <201704141941.v3EJfmCW003347@repo.freebsd.org> <CAOtMX2gPHWRGiE9UA5AevZz=cTv_qksAWX0H-xRjDEHp0huCVg@mail.gmail.com> <20170414201431.GF20974@zxy.spb.ru> <CEC6CDCF-2EF2-4CEF-BF54-91F3021EF262@gmail.com> <0CAE4B1C-228B-4C71-86E9-4337753DFF74@lerctr.org> <EC89EB67-7854-4DE6-BD40-2626FF993181@gmail.com> <A0AA951D-6F45-46E3-8B95-4254AA7899E6@lerctr.org> <12820BAB-D8BA-4EDE-89BC-4BDB56B1E57A@gmail.com> <AB41FBB8-12D6-48D7-BE34-664D2F267A2F@lerctr.org> <15ABDD42-E2C4-4519-B736-04A56FA8C2D0@gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 4/14/17, 3:46 PM, "Ngie Cooper (yaneurabeya)" <yaneurabeya@gmail.com> wr=
ote:
=20
> On Apr 14, 2017, at 13:43, Larry Rosenman <ler@lerctr.org> wrote:
>=20
> On 4/14/17, 3:39 PM, "Ngie Cooper (yaneurabeya)" <owner-svn-src-all@f=
reebsd.org on behalf of yaneurabeya@gmail.com> wrote:
>=20
>> On Apr 14, 2017, at 13:37, Larry Rosenman <ler@lerctr.org> wrote:
>>=20
>> On 4/14/17, 3:33 PM, "Ngie Cooper (yaneurabeya)" <yaneurabeya@gmail.=
com> wrote:
>>=20
>>> On Apr 14, 2017, at 13:26, Larry Rosenman <ler@lerctr.org> wrote:
>>>=20
>>> On 4/14/17, 3:19 PM, "Ngie Cooper (yaneurabeya)" <owner-svn-src-all=
@freebsd.org on behalf of yaneurabeya@gmail.com> wrote:
>>>=20
>>>> On Apr 14, 2017, at 13:14, Slawa Olhovchenkov <slw@zxy.spb.ru> wro=
te:
>>>>=20
>>>> On Fri, Apr 14, 2017 at 01:49:51PM -0600, Alan Somers wrote:
>>>>=20
>>>>> On Fri, Apr 14, 2017 at 1:41 PM, Ngie Cooper <ngie@freebsd.org> w=
rote:
>>>>>> Author: ngie
>>>>>> Date: Fri Apr 14 19:41:48 2017
>>>>>> New Revision: 316938
>>>>>> URL: https://svnweb.freebsd.org/changeset/base/316938
>>>>>>=20
>>>>>> Log:
>>>>>> savecore: fix space calculation with respect to `minfree` in che=
ck_space(..)
>>>>>>=20
>>>>>> - 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 sp=
ace,
>>>>>> etc. I am now fully aware of `KiB` being the IEC standard for 10=
24
>>>>>> 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-us=
ers
>>>>>> can troubleshoot why check_space(..) is reporting that there isn=
't
>>>>>> enough free space.
>>>>>>=20
>>>>>> MFC after: 7 weeks
>>>>>> Reviewed by: Anton Rang <rang@acm.com> (earlier diff), cem (ear=
lier diff)
>>>>>> Tested with: positive/negative cases (see review); make tinderb=
ox
>>>>>> Sponsored by: Dell EMC Isilon
>>>>>> Differential Revision: D10379
>>>>>=20
>>>>> The free space calculation is still uselessly conservative, becau=
se it
>>>>> doesn't account for the fact that core dumps will always be eithe=
r
>>>>> 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 unt=
il
>>>>> after the compressed core dump feature was merged, because then m=
ostly
>>>>> accurate space checks will be possible. AFAIK the compressed cor=
e
>>>>> dump feature still hasn't been finished.
>>>>=20
>>>> Is posible (in the future) to use multiple swaps (on multiple disk=
s)
>>>> for save core dumps?
>>>=20
>>> Multiple swap devices is already handled by savecore(8), if one us=
es fstab(5) or dumpon(8). Otherwise, you must invoke savecore(8) on individu=
al devices.
>>>=20
>>> As far as saving to multiple disks is concerned, I would hope that=
one is using a redundancy capable filesystem (zfs) or RAID-like technology =
(gmirror, graid, LSI Fusion=E2=80=99s RAID product line) to stripe and/or mirror t=
he data across multiple disks.
>>=20
>> =E2=80=A6
>>=20
>>> How do I use multiple devices to have the system dump on all of my =
swap? I got a message about not enough space, but there (I think) was enoug=
h between multiple drives=E2=80=A6.
>>=20
>> Something like:
>>=20
>> - Create a zpool
>> - Mount zpool to /crashdumps
>> - Change dumpdir in /etc/rc.conf to be /crashdumps, e.g., echo =E2=80=98=
dumpdir=3D/crashdumps=E2=80=99
>>=20
>> ?
>> HTH,
>> -Ngie
>>=20
>> PS The issue with lack of space might be the issue that Alan broug=
ht up earlier with compressed dumps and overly conservative free space check=
s, or it might be the fact that dumpdir (default: /var/crash) is full.
>>=20
>>=20
>> I was talking about the actual crashdump to swap by the system. /va=
r/crash has 10T of space (my root pool).
>=20
> If your memory is bigger than your swap, you=E2=80=99re unfortunately no=
t able to save the mini dump if the size of the saved pages exceed the space=
on swap. I think this is where markj=E2=80=99s compressed dumps feature will come=
in handy.
> Thanks!
> -Ngie
>=20
>=20
> Yeah, I have the following:
> borg.lerctr.org /home/ler $ swapctl -l
> Device: 1024-blocks Used:
> /dev/mfid0p3 8388608 0
> /dev/mfid1p3 8388608 0
> /dev/mfid2p3 8388608 0
> /dev/mfid3p3 8388608 0
> /dev/mfid4p3 8388608 0
> /dev/mfid5p3 8388608 0
> borg.lerctr.org /home/ler $ sysctl hw.physmem
> hw.physmem: 137368682496
> borg.lerctr.org /home/ler $
>=20
> SO 6 8G partitions (48G), but the dump is larger than 8G.
=20
Yup, that=E2=80=99s not going to work. Since you=E2=80=99re using mfi(4), I=E2=80=99d try=
creating another 48GB large RAID-0 volume to help deal with that issue.
Cheers,
-Ngie
No can do, the rest of the space is zpool.
borg.lerctr.org /home/ler $ gpart show
=3D> 40 3905945520 mfid0 GPT (1.8T)
40 1600 1 efi (800K)
1640 1024 2 freebsd-boot (512K)
2664 1432 - free - (716K)
4096 16777216 3 freebsd-swap (8.0G)
16781312 3889162240 4 freebsd-zfs (1.8T)
3905943552 2008 - free - (1.0M)
=3D> 40 3905945520 mfid1 GPT (1.8T)
40 1600 1 efi (800K)
1640 1024 2 freebsd-boot (512K)
2664 1432 - free - (716K)
4096 16777216 3 freebsd-swap (8.0G)
16781312 3889162240 4 freebsd-zfs (1.8T)
3905943552 2008 - free - (1.0M)
=3D> 40 3905945520 mfid2 GPT (1.8T)
40 1600 1 efi (800K)
1640 1024 2 freebsd-boot (512K)
2664 1432 - free - (716K)
4096 16777216 3 freebsd-swap (8.0G)
16781312 3889162240 4 freebsd-zfs (1.8T)
3905943552 2008 - free - (1.0M)
=3D> 40 3905945520 mfid3 GPT (1.8T)
40 1600 1 efi (800K)
1640 1024 2 freebsd-boot (512K)
2664 1432 - free - (716K)
4096 16777216 3 freebsd-swap (8.0G)
16781312 3889162240 4 freebsd-zfs (1.8T)
3905943552 2008 - free - (1.0M)
=3D> 40 3905945520 mfid4 GPT (1.8T)
40 1600 1 efi (800K)
1640 1024 2 freebsd-boot (512K)
2664 1432 - free - (716K)
4096 16777216 3 freebsd-swap (8.0G)
16781312 3889162240 4 freebsd-zfs (1.8T)
3905943552 2008 - free - (1.0M)
=3D> 40 3905945520 mfid5 GPT (1.8T)
40 1600 1 efi (800K)
1640 1024 2 freebsd-boot (512K)
2664 1432 - free - (716K)
4096 16777216 3 freebsd-swap (8.0G)
16781312 3889162240 4 freebsd-zfs (1.8T)
3905943552 2008 - free - (1.0M)
borg.lerctr.org /home/ler $
=20
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3D9A20AF-074F-494A-95FF-7A39CC964EA3>