[ale] rsync comparisons

[Björn Gustafsson]

Oh, worst-case scenario: millions of files and NFS.  The overhead from
NFS stat() calls is probably 95% of your time.  If you can run where
*one* of the directories is on a local drive, that'll probably nearly
double the speed.

On Thu, Apr 1, 2010 at 3:56 PM, Robert Coggins <ale at cogginsnet.com> wrote:
> looks like it but they are 2 nfs mounts on one box.
>
> On 04/01/2010 03:55 PM, Jeff Hubbs wrote:
>> Is this a box-to-same-box rsync?
>>
>> On 4/1/10 3:29 PM, Robert Coggins wrote:
>>> I am using -a --delete and --eclude.  Pretty Basic.
>>>
>>> To be honest I think my problem is with the Source.  It even does an ls
>>> very slow.  There are probably more than 1 million files in this 20GB.
>>>
>>> On 04/01/2010 02:49 PM, Björn Gustafsson wrote:
>>>
>>>> Which switches are you using now?  It doesn't sound like adding the
>>>> ones discussed so far will help.
>>>>
>>>> On Thu, Apr 1, 2010 at 11:41 AM, Robert Coggins<ale at cogginsnet.com>  wrote:
>>>>
>>>>> Well, what I a seeing is the syncing of roughly 20GB taking over an hour
>>>>> for just a few megs of differences.  It stays in the "building file
>>>>> list..." for almost all of this time.  I am trying to find a way to
>>>>> speed that up.
>>>>>
>>>>> Rob
>>>>>
>>>>> On 04/01/2010 11:37 AM, scott wrote:
>>>>>
>>>>>> rsync compares on a file level BUT it compares timedate stamps/sizes
>>>>>> in "quick mode" (which is default).  but if you want it to compare
>>>>>> file to file, use "-c or --checksum" option.  Now this puts a heavier
>>>>>> load on both systems, since it does a MD5 checksum on every file that
>>>>>> has the same timedate stamp/size on both sides of the sync.  Now if
>>>>>> you want to force the copy of the whole file instead of the changed
>>>>>> blocks, use the --whole-file option with it.
>>>>>>
>>>>>> I would use this ( -c&  --whole-file) sparingly.  It is going to slow
>>>>>> down the copies, put heavier loads on both ends and transfer more data
>>>>>> (control data) back and forth.  I dont know your situation so I cant
>>>>>> say to use it or or not.
>>>>>>
>>>>>> scott
>>>>>>
>>>>>>
>>>>>> On Thu, Apr 1, 2010 at 11:00 AM, Robert Coggins<ale at cogginsnet.com>  wrote:
>>>>>>
>>>>>>> Is there a way to do file level comparisons and not block level
>>>>>>> comparisons using rsync?
>>>>>>>
>>>>>>> Rob

-- 
Björn Gustafsson