Concerned About Upcoming Drive Copy

[Anna]

(SNIP)

with all due respect to Anna's input,
the cheap ones she mentioned ($10 @)
typically have the very serious flaw
of very poor air flow (which means
the drive runs hot (BAD))

two other problem with these units:
they add one or two extra connection
points, the tend to force one to place
the unit high in the case (assuming you
are using a tower unit) which typically
means exceeding the recommended max 18"
IDE cable limit

there's nothing wrong with using bare
drives that you only plug in when you do
a weekly backup
bill

bill:
All I can tell you (and others) is that over the years (for about six now)
we've installed hundreds of these all-plastic inexpensive (they've since
become more expensive than $10 I regret to report) mobile racks (most of
which were no-name generic types) in hundreds of desktop computers and we
found no performance problems involving heat-related issues with these racks
as compared with the more expensive all-aluminum racks. I have no idea of
what you're talking about with reference to your statement about "two extra
connection points" and the need "to place the unit high in the case".
Anna

 

[willbill]

(SNIP)

bill:
All I can tell you (and others) is that over the years
(for about six now)

i started using the cheap units 10 years ago

so i've had a bit longer to think about it

we've installed hundreds of these all-plastic inexpensive (they've since
become more expensive than $10 I regret to report) mobile racks (most of
which were no-name generic types) in hundreds of desktop computers and we
found no performance problems

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

the issue isn't "performance"

the issues are reliability/longevity

involving heat-related issues with these racks
as compared with the more expensive all-aluminum racks. I have no idea of
what you're talking about with reference to your statement about "two extra
connection points" and the need "to place the unit high in the case".

any hardware oriented person would immediately
see that these units require extra contact points
in the data connection, as well as typically
needing longer IDE data cables

with SATA, cables are ok up to maybe 30/36"

with IDE the number i've seen is 18"

afaik, the OP's 6 250GB hard drives are IDE

the one thing that has concerned me most
about these units (that you like), is the
questionable (poor) air flow over the
hard drive, and the likely reality that
their small fan is much less reliable
(than typcial case fans (80/120mm))

i used them 10-to-5 years ago; i thought
about it; i no longer use them; there are
better, cheaper, more reliable solutions;
for backup (which is the main topic here),
as well as for secondary storage

the only thing going for your solution
is that it is seen by the everyday user
as somehow being a superior solution,
as well as very convenient

in my own experience, it isn't on either

the one thing that hard drives need is
great air flow, and these units that
you like, don't cut it on air flow

my suggestion doesn't cost an extra penny

the units that you suggest, cost money,
have poor air flow, and have additional
contact points

hard drives are squirley enough without
adding that to the mix

bill

 

[Anna]

i started using the cheap units 10 years ago

so i've had a bit longer to think about it



^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

the issue isn't "performance"

the issues are reliability/longevity



any hardware oriented person would immediately
see that these units require extra contact points
in the data connection, as well as typically
needing longer IDE data cables

with SATA, cables are ok up to maybe 30/36"

with IDE the number i've seen is 18"

afaik, the OP's 6 250GB hard drives are IDE

the one thing that has concerned me most
about these units (that you like), is the
questionable (poor) air flow over the
hard drive, and the likely reality that
their small fan is much less reliable
(than typcial case fans (80/120mm))

i used them 10-to-5 years ago; i thought
about it; i no longer use them; there are
better, cheaper, more reliable solutions;
for backup (which is the main topic here),
as well as for secondary storage

the only thing going for your solution
is that it is seen by the everyday user
as somehow being a superior solution,
as well as very convenient

in my own experience, it isn't on either

the one thing that hard drives need is
great air flow, and these units that
you like, don't cut it on air flow

my suggestion doesn't cost an extra penny

the units that you suggest, cost money,
have poor air flow, and have additional
contact points

hard drives are squirley enough without
adding that to the mix

bill

bill:
I can only reiterate what I previously stated re our experience with mobile
racks housing removable hard drives...

Over the past six years we've probably installed somewhere around 1,000 of
these mobile racks in a wide variety of desktop PC systems.

Our experience with this hardware equipment has been most positive. We've
rarely encountered heat-related problems that we could ascribe to these
mobile racks.

We've detected no HD performance degradation caused by this equipment and
we've seen no significant longevity issues in terms of failing mobile racks.

We've found no particular need to install the racks "high in the case" as
you put it. We've installed the racks in every conceivable position where a
5 1/4" bay was available for a rack's installation and we've encountered no
problems in so doing. Rarely have we needed to use data cables exceeding
18". In a relatively few cases, because of tower case height, there was a
need for 24" cables, but we've never determined a performance issue arose
because of that increased cable length. I can't remember the last time we
used a 36" data cable.
Anna

 

[Arno Wagner]

Anna wrote:

(SNIP)

[...]
the issue isn't "performance"

the issues are reliability/longevity

any hardware oriented person would immediately
see that these units require extra contact points

You probably mean "connectors".

in the data connection, as well as typically
needing longer IDE data cables

with SATA, cables are ok up to maybe 30/36"

The standard says 1m, i.e. about 40". The comittee finally left
the stone age and specified the length in metric units.

with IDE the number i've seen is 18"

That is correct.

Arno

 

[Arno Wagner]

problems in so doing. Rarely have we needed to use data cables exceeding
18". In a relatively few cases, because of tower case height, there was a
need for 24" cables, but we've never determined a performance issue arose
because of that increased cable length. I can't remember the last time we
used a 36" data cable.

Are you sure you ever successfully did? I have had massive CRC
errors with 36" cables on two different controllers and with
different disks. Massive enough that the kernel decided
after a few minutes the disk was defective and disabled it.

Cut down to 24" (Only one disk possible), the same cables
worked ok for HDDs.

Arno

 

[Anna]

Are you sure you ever successfully did? I have had massive CRC
errors with 36" cables on two different controllers and with
different disks. Massive enough that the kernel decided
after a few minutes the disk was defective and disabled it.

Cut down to 24" (Only one disk possible), the same cables
worked ok for HDDs.

Arno

Arno:
It's quite possible those kind of errors were attributable to using a
non-spec 36" signal cable. As I stated, we rarely ever had need to use a 36"
data cable. The few times we did I can't personally recall any particular
problem(s) resulting from their use but I would never recommend them as a
general proposition because of reports such as yours. As a matter of fact we
were loathe to install a data cable > 18" although I must admit we installed
a fair number of 24" ones and I can't remember any problems with them.
Anna