Re: [ldm-users] 20151028: 20151028: Pqact FILE writes with custom removal?

  • To: Neil Smith <n-smith2@xxxxxxxx>
  • Subject: Re: [ldm-users] 20151028: 20151028: Pqact FILE writes with custom removal?
  • From: Donna Cote <d-cote@xxxxxxxx>
  • Date: Thu, 29 Oct 2015 11:01:31 -0500
It's centos 6:

CentOS release 6.6 (Final)



On Thu, Oct 29, 2015 at 10:57 AM, Neil Smith <n-smith2@xxxxxxxx> wrote:

> Donna,
> Yours is zfs on centos 6.x or 7.x?
>
> Neil
>
> On Oct 28, 2015, at 3:22 PM, Donna Cote <d-cote@xxxxxxxx> wrote:
>
> Tom,
>
> We moved our storage LDM system to zfs (on the storage disks, I don't
> think the system filesystems changed) after experiencing problems with
> scour on xfs.
>
> When using xfs, we saw the load average regularly rise to 50, 60, once to
> 110 (15-minute average over all CPUs). Even after the job of removing a
> day's worth of radar data (x days back) was moved to a bash script. The
> scours would start stacking (per Karen's definition) and I even created a
> bash script to kill all scour jobs every 3 hours.
>
> Now, with zfs, the load average rarely rises above 6 and the amount of
> data coming in just about equals the amount of old data we remove every
> day. The scour jobs have not done any stacking.
>
> Donna
> The Academy
> Texas A&M University
>
>
> On Wed, Oct 28, 2015 at 11:20 AM, Tom Yoksas <yoksas@xxxxxxxx> wrote:
>
>> Hi Mike,
>>
>> On 10/28/2015 10:02 AM, Michael Dross wrote:
>>
>>> Is there one type of filesystem that is more efficient at handling
>>> these types file large volumes of finds/creations/deletions?
>>>
>>> ie. EXT4, zfs.
>>>
>>
>> We (Unidata Program Center) have had good luck with ZFS on our
>> Solaris 10 motherlode-class machines.
>>
>> It would be most interesting to hear other users experiences!
>>
>> Cheers,
>>
>> Tom
>>
>> On Oct 28, 2015, at 11:56 AM, Tom Yoksas <yoksas@xxxxxxxx> wrote:
>>>>
>>>> All,
>>>>
>>>> re: how to efficiently scour LDM-created data products from disk
>>>>
>>>> If one organizes one's data files into daily directories, the need to
>>>> 'find' each file that should be scoured can be pared down to finding
>>>> which directories+contents need to be scoured.  This does not, however,
>>>> get around the fact that deleting large numbers of files
>>>> (e.g., millions for NEXRAD Level III files kept on disk for long
>>>> periods of time) is a _very_ costly endeavor.
>>>>
>>>> Cheers,
>>>>
>>>> Tom
>>>>
>>>> On 10/28/2015 09:47 AM, Gerry Creager - NOAA Affiliate wrote:
>>>>> How often to you run your scour command? We've exercised scour pretty
>>>>> hard and were able to watch it keep up, if it were run frequently.
>>>>> There's a one-time penalty, if you've been running it, say, daily or
>>>>> less frequently, but if you run it hourly, it should keep up.
>>>>>
>>>>> gerry
>>>>>
>>>>> On Wed, Oct 28, 2015 at 10:39 AM, Steve Emmerson <emmerson@xxxxxxxx
>>>>> <mailto:emmerson@xxxxxxxx>> wrote:
>>>>>
>>>>>     LDMers,
>>>>>
>>>>>     On Wed, Oct 28, 2015 at 9:28 AM, Donna Cote <d-cote@xxxxxxxx
>>>>>     <mailto:d-cote@xxxxxxxx>> wrote:
>>>>>
>>>>>         I would like to ask for a more io-friendly scour utility.
>>>>>
>>>>>
>>>>>     It's on my list (see <https://github.com/Unidata/LDM/issues/27>.
>>>>>     Can't say when I'll get around to it, though.
>>>>>
>>>>>     Regards,
>>>>>     Steve Emmerson
>>>>>
>>>>>     _______________________________________________
>>>>>     ldm-users mailing list
>>>>>     ldm-users@xxxxxxxxxxxxxxxx <mailto:ldm-users@xxxxxxxxxxxxxxxx>
>>>>>     For list information or to unsubscribe,  visit:
>>>>>     http://www.unidata.ucar.edu/mailing_lists/
>>>>> --
>>>>> Gerry Creager
>>>>> NSSL/CIMMS
>>>>> 405.325.6371
>>>>> ++++++++++++++++++++++
>>>>> “Big whorls have little whorls,
>>>>> That feed on their velocity;
>>>>> And little whorls have lesser whorls,
>>>>> And so on to viscosity.”
>>>>> Lewis Fry Richardson (1881-1953)
>>>>>
>>>>> _______________________________________________
>>>>> ldm-users mailing list
>>>>> ldm-users@xxxxxxxxxxxxxxxx
>>>>> For list information or to unsubscribe,  visit:
>>>>> http://www.unidata.ucar.edu/mailing_lists/
>>>>>
>>>>
>>>> --
>>>> +----------------------------------------------------------------------+
>>>> * Tom Yoksas                                      UCAR Unidata Program *
>>>> * (303) 497-8642 (last resort)                           P.O. Box 3000 *
>>>> * yoksas@xxxxxxxx                                    Boulder, CO 80307
>>>> *
>>>> * Unidata WWW Service                     http://www.unidata.ucar.edu/
>>>> *
>>>> +----------------------------------------------------------------------+
>>>>
>>>> _______________________________________________
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>>>> ldm-users@xxxxxxxxxxxxxxxx
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>>>>
>>>
>> --
>> +----------------------------------------------------------------------+
>> * Tom Yoksas                                      UCAR Unidata Program *
>> * (303) 497-8642 (last resort)                           P.O. Box 3000 *
>> * yoksas@xxxxxxxx                                    Boulder, CO 80307 *
>> * Unidata WWW Service                     http://www.unidata.ucar.edu/ *
>> +----------------------------------------------------------------------+
>>
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>
>
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