What filesystem for large thumbdrive

[gaf-mNDKBlG2WHs at public.gmane.org (Jerry Feldman)]

On 08/27/2010 08:30 AM, Dan Ritter wrote:
> On Fri, Aug 27, 2010 at 07:46:30AM -0400, Jerry Feldman wrote:
>  =20
>> I've been trying to push 800+GB to a USB drive at work so I can send i=
t
>> back to NY so they can restart their nightly backups. While I started =
to
>> use rsync (as a test of the NY backup script), I killed it and used cp=

>> -pRdu which does look faster. AFAIK, USB2 is spec'd at 480Mbps, but yo=
u
>> never will get close to that. In my WD Mybook II to the attached USB
>> drive from NY, I might be getting 10Mbps
>>    =20
> Just to clarify, USB2 raw speed is 480 Mbits/sec; that's 60
> Mbytes/sec for the whole interface. I believe that the mass
> storage spec is sufficiently wasteful that almost half of that
> is lost, too.
>
> Are you getting 10 Mbytes/sec or 10Mbits ? one of those is
> merely slow, the other is horrendous.
>
> -dsr-
>
>
>
>  =20
I didn't do a calculation, I was joking about the 10Mbps (Mbits). The
copy took over a week to do. I received the drive last Thursday from our
NY office, and after updating the NY backup script and making a copy so
I could test it locally, I started the backup. I did stop the backup
during the week and switched to the cp command. In this case the issues
are: (1) the WD Mybook II is a very slow device, (2) the normal nightly
backups over the LAN run taking up cycles and disk I/O. In any case, by
starting with the rsync script I was able to test my changes to the NY
script so all they have to do on Monday when they get the drive is to
plug it in and restart the cronjob. In contrast, what my production NFS
server does of GB ethernet in minutes, the MyBook II (also with GB
ethernet) does in hours. In any case, I think it came out to about 17
MBps very roughly (1 week for about 819GB).

--=20
Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
Boston Linux and Unix
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