[K12OSN] Poor performance woes
Jomegat
jomegat at jomegat.com
Wed Sep 21 01:07:44 UTC 2011
On 09/20/2011 09:01 PM, Gideon Romm wrote:
> Should be NBD_SWAP = True
>
> (it won't understand "on") :)
Noted and applied. Thanks!
>
> On Tue, Sep 20, 2011 at 6:51 PM, Jomegat<jomegat at jomegat.com> wrote:
>> On 09/20/2011 05:02 PM, Gideon Romm wrote:
>>>
>>> That just tells you the service is on. If you don't have NBD_SWAP in
>>> your lts.conf, then you are not using it.
>>
>> OK, there was nothing of the sort in lts.conf. I added this line:
>> NBD_SWAP=on
>>
>> I'll test it when I can get over there.
>>
>> Thanks a million.
>>
>>>
>>> I believe there is also a parameter to use local swap from a hard
>>> drive, though I don't recall. Perhaps check the docs. Otherwise, if I
>>> remember, I will look in the code.
>>>
>>> -Gadi
>>>
>>> On Tue, Sep 20, 2011 at 4:51 PM, Jomegat<jomegat at jomegat.com> wrote:
>>>>
>>>> On 09/20/2011 04:36 PM, Gideon Romm wrote:
>>>>>
>>>>> Try enabling NBD_SWAP. If the clients have insufficient RAM, the best
>>>>> you can do is add swap space and hope the OS will swap out something
>>>>> else.
>>>>
>>>> Thanks. I've already got that enabled as best I can tell. Here's a
>>>> snippet
>>>> from chkconfig --list:
>>>>
>>>> xinetd based services:
>>>> [snip]
>>>> nbdrootd: on
>>>> nbdswapd: on
>>>>
>>>> Maybe that's where the 21MiB/sec is coming from.
>>>>
>>>> As soon as I can get back to the school, I'll run top on the TC and see
>>>> what's going on.
>>>>
>>>> Would it be possible (or advisable) to run swap on the TC from a local HD
>>>> instead of over the network?
>>>>
>>>>>
>>>>> -Gadi
>>>>>
>>>>> On Tue, Sep 20, 2011 at 3:18 PM, Jomegat<jomegat at jomegat.com> wrote:
>>>>>>
>>>>>> I have a K12Linux setup based on EL6-64. The TC's are ancient i686's
>>>>>> with
>>>>>> 256M RAM and 10/100 nics. The TS has a gigE NIC, and between the TS&
>>>>>> TCs
>>>>>> is a managed switch with 2 gigE ports and 24 10/100 ports. The TS is
>>>>>> connected via one of the gigE's.
>>>>>>
>>>>>> We have a student who is having real performance problems when he loads
>>>>>> a
>>>>>> page. I went in today to be there while he was experiencing woe, and
>>>>>> ran
>>>>>> the system monitor applet.
>>>>>>
>>>>>> When he loads the web page - with no flash in it that I can find - the
>>>>>> network maxes out at 12MiB/sec, and it takes an eternity for the page
>>>>>> to
>>>>>> load. He reports that sometimes this particular page will cause the TC
>>>>>> to
>>>>>> crash (black screen with text followed by login screen), but he was not
>>>>>> able
>>>>>> to reproduce that while I was there. I suspect there is some user
>>>>>> error
>>>>>> involved in the crash scenario, but it will be difficult to prove.
>>>>>>
>>>>>> I had tried running firefox as a local app last month, but the school
>>>>>> needs
>>>>>> flash, and it requires 512M. Performance on these TC's was
>>>>>> substantially
>>>>>> worse when running FF as a local app, so I backed off of that.
>>>>>>
>>>>>> The page he was trying to load is password protected, but I had him
>>>>>> ctrl-U
>>>>>> while he had it open, and save the source to a file which I can share
>>>>>> if
>>>>>> need be. It is filled with javascript, but I'm not sure that's the
>>>>>> culprit
>>>>>> (though it seems the most likely suspect). I found no .flv, FLV, .swf,
>>>>>> or
>>>>>> .SWF in the file anywhere.
>>>>>>
>>>>>> As an experiment, I connected a monitor, keybd, and mouse directly to
>>>>>> the
>>>>>> server and had him login there. The page loads just fine that way.
>>>>>> That
>>>>>> might be a possible solution, but for some reason, the display is
>>>>>> incredibly
>>>>>> blurry. If I make that permanent, I'd have to run some cable through
>>>>>> the
>>>>>> wall (they're pinched in the door right now, and barely reach).
>>>>>>
>>>>>> Before they called me in to look at this, he had been bringing his
>>>>>> mom's
>>>>>> laptop to school so he could do his work (it's an online course). If
>>>>>> it
>>>>>> crashes while he is taking a quiz, he loses a test attempt or gets a
>>>>>> bad
>>>>>> grade, so this has to be reliable.
>>>>>>
>>>>>> His mom is on the school board, and she is pushing the school to
>>>>>> abandon
>>>>>> LTSP in favor of a Windows solution. They think that if they install
>>>>>> some
>>>>>> flavor of windows on the TC's they will get better performance, but I
>>>>>> believe they won't, as flash will need 512M no matter the OS. I think
>>>>>> they
>>>>>> will need all new PC's if they go that route.
>>>>>>
>>>>>> I am on the cusp of losing my network to Windows, at which point I will
>>>>>> resign my post as unpaid volunteer sysadmin, so if I sound a little
>>>>>> desperate, now you know why.
>>>>>>
>>>>>> Any help here would be greatly appreciated.
>>>>>>
>>>>>> --
>>>>>> Jim Thomas Principal Applications Engineer Bittware, Inc
>>>>>> jthomas at bittware.com http://www.bittware.com (603) 226-0404 x536
>>>>>> The problem with the future is that it keeps turning into the present -
>>>>>> Hobbes
>>>>>>
>>>>>> _______________________________________________
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>>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>
>>>>
>>>> --
>>>> Jim Thomas Principal Applications Engineer Bittware, Inc
>>>> jthomas at bittware.com http://www.bittware.com (603) 226-0404 x536
>>>> The problem with the future is that it keeps turning into the present -
>>>> Hobbes
>>>>
>>>> _______________________________________________
>>>> K12OSN mailing list
>>>> K12OSN at redhat.com
>>>> https://www.redhat.com/mailman/listinfo/k12osn
>>>> For more info see<http://www.k12os.org>
>>>>
>>>
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>>
>>
>> --
>> Jim Thomas jomegat at jomegat.com
>> "And" is a word that should never be used at the beginning of a sentence.
>>
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>
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--
Jim Thomas jomegat at jomegat.com
"And" is a word that should never be used at the beginning of a sentence.
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