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Hi Andy,

I may have spoke too soon.  I use a script that runs "find" on the dataserver and kicks 
out names, dates and sizes but the dates being used were "Change time" and not "mod time". 
  The files' change times were being updated with access (a different problem).  No new 
files were written.

I have now freed up a little space and will see if anything gets written to the 
dataserver.  Sorry for the confusion.

Patrick

On 06/24/2010 09:11 PM, Andrew Hanushevsky wrote:
> Hi Patrick,
>
> No, you got that right; the problem is that this applies to the
> redirector as well and you needed to restart it.
>
> Andy
>
> ----- Original Message ----- From: "Patrick McGuigan" <[log in to unmask]>
> To: "Andrew Hanushevsky" <[log in to unmask]>
> Cc: "Yang, Wei" <[log in to unmask]>; "xrootd-l"
> <[log in to unmask]>
> Sent: Thursday, June 24, 2010 7:04 PM
> Subject: Re: Data Migration issues
>
>
>> Hi Andy,
>>
>> This doesn't seem to be working for our systems?
>>
>> I included:
>>
>> cms.space min 15t 15t
>>
>> in the configuration, and restarted the dataservers yesterday. I
>> checked one
>> of the data servers and saw that files were written today on the system.
>>
>> I take the config line to mean that there must be at least 15TB
>> available before
>> the dataserver will write. Do the two values have to be different?
>>
>> Patrick
>>
>>
>> On 06/22/2010 11:03 PM, Andrew Hanushevsky wrote:
>>> Hi Patrick,
>>>
>>> Yes, the analysis is correct. You can set it up to allow deletions but
>>> disallow creation of new files via the redirector.
>>>
>>> Andy
>>>
>>> ----- Original Message ----- From: "Yang, Wei" <[log in to unmask]>
>>> To: "Patrick McGuigan" <[log in to unmask]>
>>> Cc: "xrootd-l" <[log in to unmask]>
>>> Sent: Tuesday, June 22, 2010 5:07 PM
>>> Subject: Re: Data Migration issues
>>>
>>>
>>>> I think you only need to change the configuration for the data server.
>>>> Redirector gets space info from cmsd on data servers. With cms.space,
>>>> you can still _write_ to the data server if you access it directly.
>>>> But if you ask the redirector to choose a data server for you for
>>>> writing, the redirector won't choose this particular data server.
>>>>
>>>> regards,
>>>> Wei Yang | [log in to unmask] | 650-926-3338(O)
>>>>
>>>>
>>>> On Jun 22, 2010, at 4:59 PM, Patrick McGuigan wrote:
>>>>
>>>>> Thanks Wei,
>>>>>
>>>>> I had thought that something like this method would be available, does
>>>>> your suggestion require a specific configuration in the redirector? We
>>>>> are using the defaults with respect to how the redirector chooses
>>>>> dataservers.
>>>>>
>>>>> Regards,
>>>>> Patrick
>>>>>
>>>>> On 06/22/2010 06:54 PM, Yang, Wei wrote:
>>>>>> Hi Patrick,
>>>>>>
>>>>>> If you set all.export path to readonly, you won't be able to delete.
>>>>>> I never tried any of this because but here is an idea: You may use
>>>>>> cms.space directive to set the minimum space required for the data
>>>>>> server to be writeable, and set a high number (above the total space
>>>>>> of that data server) so that redirector always think the data server
>>>>>> runs out of space. In that case, you can keep on deleting without
>>>>>> worrying about new data getting written to it.
>>>>>>
>>>>>> regards,
>>>>>> Wei Yang | [log in to unmask] | 650-926-3338(O)
>>>>>>
>>>>>>
>>>>>> On Jun 22, 2010, at 4:20 PM, Patrick McGuigan wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>>
>>>>>>> I am preparing to replace 6 smaller dataservers with 2 much larger
>>>>>>> systems and I am curious if anyone has advice on making the
>>>>>>> transition.
>>>>>>> There is about 40TB of data currently on the smaller dataservers.
>>>>>>>
>>>>>>> A couple of caveats:
>>>>>>> 1) The existing data is organized in cache groups on the
>>>>>>> dataservers and
>>>>>>> the cgroup information will need to propagate to the new dataservers
>>>>>>>
>>>>>>> 2) The smaller dataservers are in a production system and I want to
>>>>>>> minimize any downtime associated with data on these servers.
>>>>>>>
>>>>>>> 3) A sizable portion of the 40TB is no longer relevant to the
>>>>>>> production
>>>>>>> system and potentially could be deleted (or at least not migrated)
>>>>>>>
>>>>>>>
>>>>>>> It eases my burden if I can delete data from all the production
>>>>>>> dataservers at the same time. However, if I delete data from the 6
>>>>>>> servers that will be migrated, I don't want new data to take its
>>>>>>> place.
>>>>>>>
>>>>>>>
>>>>>>> I was hoping that I could somehow setup the existing dataservers
>>>>>>> in a
>>>>>>> readonly configuration but still be able to delete data via the
>>>>>>> redirector (actually from a FUSE client talking to a CNS service on
>>>>>>> the
>>>>>>> redirector). Is this possible?
>>>>>>>
>>>>>>>
>>>>>>> From my reading, I can make the dataservers readonly by altering the
>>>>>>> all.export line:
>>>>>>>
>>>>>>> all.export /xrd readonly
>>>>>>>
>>>>>>> But I am not sure if this still allows deletions.
>>>>>>>
>>>>>>> Also, does the use of oss.cache directives affect the readonly
>>>>>>> status?
>>>>>>>
>>>>>>>
>>>>>>> If anyone has experience with performing this type of migration,
>>>>>>> or if
>>>>>>> anyone has suggestions, I would be very thankful to hear from you.
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> Patrick
>>>>>>>
>>>>>>>
>>>>>>
>>>>
>>>>
>>