FreeBSD/ZFS on 9.3-RELEASE chews up memory with "wide" directories when calling readdir, etc; causes trap 12 panics
yaneurabeya at gmail.com
Wed Apr 8 17:22:55 UTC 2015
On Apr 8, 2015, at 9:15, Alan Somers <asomers at freebsd.org> wrote:
> On Tue, Apr 7, 2015 at 12:37 AM, Garrett Cooper <yaneurabeya at gmail.com> wrote:
>> Long story short, I had a lot of mail spooled up in /var/spool. When I did ls /var/spool, ZFS chewed up almost all 12GB of my memory in <10 mins (because there were enough files there) and the system eventually panicked because [I assume that a memory allocation failed and] a trap 12 panic was caught. I don’t have the exact details, but it should be relatively easy to repro (YMMV if you have a boatload of RAM):
>> for i in $(seq 1 $repro_end); do mktemp tmp.XXXXXXXXXXXX; done
>> This might be ameliorated via r281026, but this change is only available in CURRENT (so far), and I haven’t tested it.
>> Are there any comments about this scalability issue with FreeBSD/ZFS?
> I spent the last ~ 24 hours creating 58,567,635 empty files in one
> directory. I can ls it without crashing on a machine with 32 GB RAM.
> # /usr/bin/time -l ls /tmp/tmp | wc
> 1061.21 real 225.54 user 36.61 sys
> 9720268 maximum resident set size
> 28 average shared memory size
> 8 average unshared data size
> 128 average unshared stack size
> 2425013 page reclaims
> 0 page faults
> 0 swaps
> 108036 block input operations
> 0 block output operations
> 0 messages sent
> 0 messages received
> 0 signals received
> 108004 voluntary context switches
> 2428 involuntary context switches
> 58567635 58567635 644243985
Strange. I wish I could gather more details about how many files were located there. Distance and time that they were created might manner; in my case there were _many_ spooled up emails that hadn’t been sent because I didn’t take the time to fix my SMTP settings via comcast/gmail.
RAM amount might matter too. 12GB vs 32GB is a bit of a difference.
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 496 bytes
Desc: Message signed with OpenPGP using GPGMail
More information about the freebsd-stable