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From: bobneworleans on 21 Feb 2010 16:45
I want to add external storage to my Dell Studio XPS. It has a
built-in eSATA port so the Seagate FreeAgentXTreme is an
attractive choice. However, I would prefer to set up a 3-drive
RAID 5 array in order to get fault tolerance.

Dell Tech Support stated that the built-in controller supports
RAID and the Tech Guide does mention RAID 5. Does this
mean I will not need another controller?

In addition to the eSATA port, the laptop has an ExpressCard
34/54 slot, gb Ethernet, 1394, and USB. What's the best way to
physically connect the laptop to the array?

Do you have any specific hardware recommendations?
From: Arno on 21 Feb 2010 19:10
bobneworleans(a)yahoo.com <bobneworleans(a)yahoo.com> wrote:
> I want to add external storage to my Dell Studio XPS. It has a
> built-in eSATA port so the Seagate FreeAgentXTreme is an
> attractive choice. However, I would prefer to set up a 3-drive
> RAID 5 array in order to get fault tolerance.

Why not use a 2 drive RAID1? Disks have gooten so chep, that
I suspect this is more cost effective.

> Dell Tech Support stated that the built-in controller supports
> RAID and the Tech Guide does mention RAID 5.

What is usually mentioned is software RAID. Even then it
depends on the configutation, what actually is supported.

> Does this
> mean I will not need another controller?

At the very least you will need an SATA port multiplier.
One eSATA port can only drive one SATA disk. For the
port multiplier, your controller needs to be port multiplier
capable.

> In addition to the eSATA port, the laptop has an ExpressCard
> 34/54 slot, gb Ethernet, 1394, and USB. What's the best way to
> physically connect the laptop to the array?

> Do you have any specific hardware recommendations?


It really depends on what you want.

If you want disk fault tolerance, RAID is a valid choice,
but only if your damage model does not include "I dropped
the whole array". In that case, you can look for an external
disk case with SATA port multiplier, but only if your
controller does support it.

Note that RAID is not backup. If you mess up your data on
the RAID, it will be gone. It is quite possible that a better
set-up for you is to have 2-3 independent external drives.
Use one as storage extension and the other two as alternate
backup drives that you copy important stuff to.

Arno
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno(a)wagner.name
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans
From: bobneworleans on 22 Feb 2010 22:33
On Feb 21, 6:10 pm, Arno <m...(a)privacy.net> wrote:
> bobneworle...(a)yahoo.com <bobneworle...(a)yahoo.com> wrote:

<snip>

> > In addition to the eSATA port, the laptop has an ExpressCard
> > 34/54 slot, gb Ethernet, 1394, and USB.  What's the best way to
> > physically connect the laptop to the array?
> > Do you have any specific hardware recommendations?
>
> It really depends on what you want.
>
> If you want disk fault tolerance, RAID is a valid choice,
> but only if your damage model does not include "I dropped
> the whole array". In that case, you can look for an external
> disk case with SATA port multiplier, but only if your
> controller does support it.

I'm only trying to protect my data against typical drive failure.
I would have thought RAID 5 would be preferred to RAID 1
because the overhead is so much less, but I understand your
point.

> Note that RAID is not backup. If you mess up your data on
> the RAID, it will be gone. It is quite possible that a better
> set-up for you is to have 2-3 independent external drives.
> Use one as storage extension and the other two as alternate
> backup drives that you copy important stuff to.

I will consider this alternative but at the moment am leaning
toward RAID for fault tolerance.

> Arno

Bob
From: mscotgrove on 23 Feb 2010 05:26
On Feb 23, 3:33 am, "bobneworle...(a)yahoo.com"
<bobneworle...(a)yahoo.com> wrote:
> On Feb 21, 6:10 pm, Arno <m...(a)privacy.net> wrote:
>
> > bobneworle...(a)yahoo.com <bobneworle...(a)yahoo.com> wrote:
>
> <snip>
>
> > > In addition to the eSATA port, the laptop has an ExpressCard
> > > 34/54 slot, gb Ethernet, 1394, and USB.  What's the best way to
> > > physically connect the laptop to the array?
> > > Do you have any specific hardware recommendations?
>
> > It really depends on what you want.
>
> > If you want disk fault tolerance, RAID is a valid choice,
> > but only if your damage model does not include "I dropped
> > the whole array". In that case, you can look for an external
> > disk case with SATA port multiplier, but only if your
> > controller does support it.
>
> I'm only trying to protect my data against typical drive failure.
> I would have thought RAID 5 would be preferred to RAID 1
> because the overhead is so much less, but I understand your
> point.
>
> > Note that RAID is not backup. If you mess up your data on
> > the RAID, it will be gone. It is quite possible that a better
> > set-up for you is to have 2-3 independent external drives.
> > Use one as storage extension and the other two as alternate
> > backup drives that you copy important stuff to.
>
> I will consider this alternative but at the moment am leaning
> toward RAID for fault tolerance.
>
> > Arno
>
> Bob

All backup plans should have data also offsite. This covers fire,
theft, major lightening strike.

Offsite can include online backup, or a spare disk drive the office,
mother in laws house etc.

Personally, I like online as it is fully automatic and does not need
to be remembered - but is probably only suitable for sub 100GB of
data, and no more than 1GB of changed data a day. There are concerns
about online backup security, but the choice is yours.

Michael
From: Arno on 23 Feb 2010 08:51
mscotgrove(a)aol.com <mscotgrove(a)aol.com> wrote:
> On Feb 23, 3:33?am, "bobneworle...(a)yahoo.com"
[...]
> All backup plans should have data also offsite. This covers fire,
> theft, major lightening strike.

> Offsite can include online backup, or a spare disk drive the office,
> mother in laws house etc.

> Personally, I like online as it is fully automatic and does not need
> to be remembered - but is probably only suitable for sub 100GB of
> data, and no more than 1GB of changed data a day. There are concerns
> about online backup security, but the choice is yours.

I use that. In fact I rented a vserver for that purpose as this
turned out to be the cheapest option. Securty wise I use
GnuPG on any critical stuff before uploading, but otherwise
I trust the provider to not to snoop (would be very bad for
their business and criminal in addition under Geman law) and
have reasonable security on the server instance itself.

And no, online is not necessarily fully automatic. Only
if you buy fully automatic online backup ;-)

Arno
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno(a)wagner.name
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans
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