Most likely OT: rsync to cifs mount

[Rick Stevens]

On 04/01/2015 10:57 AM, Ranjan Maitra wrote:
> Thanks!
>
>
>> That's EMC's "OneFS" filesystem (EMC bought out Isilon).
>>
>>> On Wed, 1 Apr 2015 08:07:34 -0500 Ranjan Maitra <maitra.mbox.ignored at inbox.com> wrote:
>>>
>>>> Thanks to both Cameron and you, Bob!
>>>>
>>>> After the transfer, here is what we have, on that filesystem:
>>>>
>>>> $ du -sh kmeans --apparent-size
>>>> 154G	kmeans
>>>>
>>>> $ du -sh kmeans
>>>> 628G	kmeans
>>>>
>>>> So, I guess that leaves me (and others) stuck.
>>
>> Is "kmeans" on the target or the source filesystem?
>
> Sorry, this is on the target (Isilon FS). Locally (on a F21 workstation and ext4 FS) it clocks in at 154G and 159G respectively.
>
>   If it's the source,
>> keep in mind that OneFS can do data dedupes (assuming it's enabled),
>> but it is a NAS device (NFS and/or SMB). I don't believe it's capable
>> of sparse files (few NAS are). The data dedupe would reduce the actual
>> storage on disk on the EMC device , but not report it as a sparse
>> filesystem
>
>
> Yes, I have been given this explanation, as well as that th block size is turned up on the isilon. This means that the size of a single file is probably 16K, rather than the typical 4K desktop file size. However, I do not have files that are that small where it would make a difference. So, I don't know.
>
> I see: the dedupe is supposed to run over weekends but I am not sure what it does.

Deduping is a process by which redundant data on a storage device is
removed. You can loosely think of it as "gzip" at the block level on
the storage device itself (although gzip is _compression_, not
deduping). Everything on the device will _appear_ normal, but the
redundancies will have been removed and less physical space used.

Here's a good explanation:

	http://www.webopedia.com/TERM/D/data_deduplication.html

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- Rick Stevens, Systems Engineer, AllDigital    ricks at alldigital.com -
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