scp: Write Failed: Cannot allocate memory

Tue Jul 5 17:03:24 UTC 2011

I'm running virtualbox 3.2.12_1 if that has anything to do with it.

sysctl vfs.zfs.arc_max: 6200000000

While I'm trying to scp, kstat.zfs.misc.arcstats.size is hovering right around that value, sometimes above, sometimes below (that's as it should be, right?). I don't think that it dies when crossing over arc_max. I can run the same scp 10 times and it might fail 1-3 times, with no correlation to the arcstats.size being above/below arc_max that I can see.

Scott

On Jul 5, 2011, at 3:00 AM, Peter Ross wrote:

> Hi all,
> 
> just as an addition: an upgrade to last Friday's FreeBSD-Stable and to VirtualBox 4.0.8 does not fix the problem.
> 
> I will experiment a bit more tomorrow after hours and grab some statistics.
> 
> Regards
> Peter
> 
> Quoting "Peter Ross" <Peter.Ross at bogen.in-berlin.de>:
> 
>> Hi all,
>> 
>> I noticed a similar problem last week. It is also very similar to one reported last year:
>> 
>> http://lists.freebsd.org/pipermail/freebsd-stable/2010-September/058708.html
>> 
>> My server is a Dell T410 server with the same bge card (the same pciconf -lvc output as described by Mahlon:
>> 
>> http://lists.freebsd.org/pipermail/freebsd-stable/2010-September/058711.html
>> 
>> Yours, Scott, is a em(4)..
>> 
>> Another similarity: In all cases we are using VirtualBox. I just want to mention it, in case it matters. I am still running VirtualBox 3.2.
>> 
>> Most of the time kstat.zfs.misc.arcstats.size was reaching vfs.zfs.arc_max then, but I could catch one or two cases then the value was still below.
>> 
>> I added vfs.zfs.prefetch_disable=1 to sysctl.conf but it does not help.
>> 
>> BTW: It looks as ARC only gives back the memory when I destroy the ZFS (a cloned snapshot containing virtual machines). Even if nothing happens for hours the buffer isn't released..
>> 
>> My machine was still running 8.2-PRERELEASE so I am upgrading.
>> 
>> I am happy to give information gathered on old/new kernel if it helps.
>> 
>> Regards
>> Peter
>> 
>> Quoting "Scott Sipe" <cscotts at gmail.com>:
>> 
>>> 
>>> On Jul 2, 2011, at 12:54 AM, jhell wrote:
>>> 
>>>> On Fri, Jul 01, 2011 at 03:22:32PM -0700, Jeremy Chadwick wrote:
>>>>> On Fri, Jul 01, 2011 at 03:13:17PM -0400, Scott Sipe wrote:
>>>>>> I'm running 8.2-RELEASE and am having new problems with scp. When scping
>>>>>> files to a ZFS directory on the FreeBSD server -- most notably large files
>>>>>> -- the transfer frequently dies after just a few seconds. In my last test, I
>>>>>> tried to scp an 800mb file to the FreeBSD system and the transfer died after
>>>>>> 200mb. It completely copied the next 4 times I tried, and then died again on
>>>>>> the next attempt.
>>>>>> 
>>>>>> On the client side:
>>>>>> 
>>>>>> "Connection to home closed by remote host.
>>>>>> lost connection"
>>>>>> 
>>>>>> In /var/log/auth.log:
>>>>>> 
>>>>>> Jul  1 14:54:42 freebsd sshd[18955]: fatal: Write failed: Cannot allocate
>>>>>> memory
>>>>>> 
>>>>>> I've never seen this before and have used scp before to transfer large files
>>>>>> without problems. This computer has been used in production for months and
>>>>>> has a current uptime of 36 days. I have not been able to notice any problems
>>>>>> copying files to the server via samba or netatalk, or any problems in
>>>>>> apache.
>>>>>> 
>>>>>> Uname:
>>>>>> 
>>>>>> FreeBSD xeon 8.2-RELEASE FreeBSD 8.2-RELEASE #0: Sat Feb 19 01:02:54 EST
>>>>>> 2011     root at xeon:/usr/obj/usr/src/sys/GENERIC  amd64
>>>>>> 
>>>>>> I've attached my dmesg and output of vmstat -z.
>>>>>> 
>>>>>> I have not restarted the sshd daemon or rebooted the computer.
>>>>>> 
>>>>>> Am glad to provide any other information or test anything else.
>>>>>> 
>>>>>> {snip vmstat -z and dmesg}
>>>>> 
>>>>> You didn't provide details about your networking setup (rc.conf,
>>>>> ifconfig -a, etc.).  netstat -m would be useful too.
>>>>> 
>>>>> Next, please see this thread circa September 2010, titled "Network
>>>>> memory allocation failures":
>>>>> 
>>>>> http://lists.freebsd.org/pipermail/freebsd-stable/2010-September/thread.html#58708
>>>>> 
>>>>> The user in that thread is using rsync, which relies on scp by default.
>>>>> I believe this problem is similar, if not identical, to yours.
>>>>> 
>>>> 
>>>> Please also provide your output of ( /usr/bin/limits -a ) for the server
>>>> end and the client.
>>>> 
>>>> I am not quite sure I agree with the need for ifconfig -a but some
>>>> information about the networking driver your using for the interface
>>>> would be helpful, uptime of the boxes. And configuration of the pool.
>>>> e.g. ( zpool status -a ;zfs get all <poolname> ) You should probably
>>>> prop this information up somewhere so you can reference by URL whenever
>>>> needed.
>>>> 
>>>> rsync(1) does not rely on scp(1) whatsoever but rsync(1) can be made to
>>>> use ssh(1) instead of rsh(1) and I believe that is what Jeremy is
>>>> stating here but correct me if I am wrong. It does use ssh(1) by
>>>> default.
>>>> 
>>>> Its a possiblity as well that if using tmpfs(5) or mdmfs(8) for /tmp
>>>> type filesystems that rsync(1) may be just filling up your temp ram area
>>>> and causing the connection abort which would be expected. ( df -h ) would
>>>> help here.
>>> 
>>> Hello,
>>> 
>>> I'm not using tmpfs/mdmfs at all. The clients yesterday were 3 different OSX computers (over gigabit). The FreeBSD server has 12gb of ram and no bce adapter. For what it's worth, the server is backed up remotely every night with rsync (remote FreeBSD uses rsync to pull) to an offsite (slow cable connection) FreeBSD computer, and I have not seen any errors in the nightly rsync.
>>> 
>>> Sorry for the omission of networking info, here's the output of the requested commands and some that popped up in the other thread:
>>> 
>>> http://www.cap-press.com/misc/
>>> 
>>> In rc.conf:  ifconfig_em1="inet 10.1.1.1 netmask 255.255.0.0"
>>> 
>>> Scott
>>> 
>>> _______________________________________________
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>>> 
>> 
>> 
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> 
> 