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From: xcyx on 10 Aug 2010 09:51
Greetings,

I am running SBS2008 on an HP ML370 G6 server. I have a total of 6 Hard
drives (2 SAS drives, and 4 SATA drives). The 2 SAS drives are raided
together with Raid 0 and SBS2008 is running off that raid. The 4 SATA drives
are are raided into 2 drives with Raid 0 as well (2 sata drives / drive).
The server now has 3 seperate drives (C,D,E). My problem is that when
copying large files from C to D drive or anywhere D to E drive or any drive
combination, speeds are fast, no problem. When copying files to an external
USB drive, it takes hours, 16 hours for 175GIG of data for example. Does
anyone know why this is occuring? are my raid correct? something I can
check?

Thank you.

From: Jim on 10 Aug 2010 11:24
On Tue, 10 Aug 2010 06:51:03 -0700, xcyx
<xcyx(a)discussions.microsoft.com> wrote:

>
>Greetings,
>
>I am running SBS2008 on an HP ML370 G6 server. I have a total of 6 Hard
>drives (2 SAS drives, and 4 SATA drives). The 2 SAS drives are raided
>together with Raid 0 and SBS2008 is running off that raid. The 4 SATA drives
>are are raided into 2 drives with Raid 0 as well (2 sata drives / drive).
>The server now has 3 seperate drives (C,D,E). My problem is that when
>copying large files from C to D drive or anywhere D to E drive or any drive
>combination, speeds are fast, no problem. When copying files to an external
>USB drive, it takes hours, 16 hours for 175GIG of data for example. Does
>anyone know why this is occuring? are my raid correct? something I can
>check?
>
>Thank you.


Don't forget that USB2 is limited to 480 Mb/sec, which in real terms
is approximately 40MB/sec. Your USB drive is probably limited further,
perhaps 30MB/s. e.g. around 35 seconds per GB - and that's on a good
day. Finally, USB drives tend to saturate quickly, so you rarely get a
sustained 30MB/s second.

We get 220GB transferred in about 9 hours overnight, so quicker than
yours, but still not fast. Clearly USB3 or eSata would be quicker.

I don't thnk it's your RAID that's the slow bit.



Jim
From: Anteaus on 11 Aug 2010 08:14

As said you are hitting the limitations of USB, pure and simple. It rarely
lives-up to its claimed throughput. A NAS box with GHz Ethernet would be a
better option. Or, external hotplug SATA.

It's either that, or for backup you need an app which will update your copy
rather then re-copying the entire lot. Lazy Mirror is one such.

IMHO RAID'ing of drives is less of a benefit than often claimed, and may
introduce troubles of its own such as inability to image or clone the disks
for disaster-recovery purposes. However, I've never seen a RAID array
perform more slowly than a single disk.

"xcyx" wrote:

> Greetings,
>
> I am running SBS2008 on an HP ML370 G6 server. I have a total of 6 Hard
> drives (2 SAS drives, and 4 SATA drives). The 2 SAS drives are raided
> together with Raid 0 and SBS2008 is running off that raid. The 4 SATA drives
> are are raided into 2 drives with Raid 0 as well (2 sata drives / drive).
> The server now has 3 seperate drives (C,D,E). My problem is that when
> copying large files from C to D drive or anywhere D to E drive or any drive
> combination, speeds are fast, no problem. When copying files to an external
> USB drive, it takes hours, 16 hours for 175GIG of data for example. Does
> anyone know why this is occuring? are my raid correct? something I can
> check?
>
> Thank you.
>
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