Scsi VS Sata for a download server

  • Thread starter Thread starter justatech2004
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justatech2004

Hi,

My company is spending a whole bunch on money on a server just to host
a very important download. It's not a single file. It's several files
where users download whatever part they need using our software client.


We're getting a Dual xeon 2.8 GHZ server with 2 GB ram and I'm not sure
what kinda drives to get. 2x73GB Scsi 10K RPM mirrored has been
recommended by some but they're tougher and much more expensive to get.
We can easily get 10K RPM Sata drives instead.

I hear they actually perform better in many cases. Would this be the
case for a download oriented server like ours?

I want to save the company money but if there is any significant
decrease in performance then I'm definitely obligated to bend over
backwards and go with the scsi.

Any comments/help would be greatly appreciated!
 
justatech2004 said:
Hi,

My company is spending a whole bunch on money on a server just to host
a very important download. It's not a single file. It's several files
where users download whatever part they need using our software client.


We're getting a Dual xeon 2.8 GHZ server with 2 GB ram and I'm not sure
what kinda drives to get. 2x73GB Scsi 10K RPM mirrored has been
recommended by some but they're tougher and much more expensive to get.
We can easily get 10K RPM Sata drives instead.

I hear they actually perform better in many cases. Would this be the
case for a download oriented server like ours?

I want to save the company money but if there is any significant
decrease in performance then I'm definitely obligated to bend over
backwards and go with the scsi.

Any comments/help would be greatly appreciated!
Click to expand...

What you _want_ if this is going to be a heavily utilized server is enough
RAM in the machine for all ongoing operations including the file downloads
to come from the RAM and not the disk. The drives shouldn't be a
performance issue unless the data changes frequently.
 
Hi John and thanks for the response.

Define "frequently" for me. It does change once every week or so but I
guess that's not a factor right?

And is 2GB ram sufficient? We have around a hundred people downloading
50 megs of data sometimes (usually 10-20)
 
justatech2004wrote:
Hi,
My company is spending a whole bunch on money on a server just to host
a very important download. It's not a single file. It's several files
where users download whatever part they need using our software client.


We're getting a Dual xeon 2.8 GHZ server with 2 GB ram and I'm not sure
what kinda drives to get. 2x73GB Scsi 10K RPM mirrored has been
recommended by some but they're tougher and much more expensive to get.
We can easily get 10K RPM Sata drives instead.

I hear they actually perform better in many cases. Would this be the
case for a download oriented server like ours?

I want to save the company money but if there is any significant
decrease in performance then I'm definitely obligated to bend over
backwards and go with the scsi.

Any comments/help would be greatly appreciated!
Click to expand...

I would recommend SATA 2 drives. You must have a system to support
the SATA 2. If not, SATA 1. Yes, in many cases, SATA will out run
SCSI.

As far as RAM goes, if you have as many users as you say, max out the
RAM as far as you can go.

I'm assuming you're going to be using some type of RAID system with
the SATA's.
 
Yes, we're going with raid 5 to mirror the drives and our hosting
company has agreed to offer us a great deal on 2x73GB SCSIs so that
settles the hard drive question since cost was the main prohibitive
factor with SCSI and that's no longer an issue.

BUT the ram question now comes in. We can get the ram up to 4GB but is
that really necessary with this many users? If yes, we'll definitely
spend the money....
 
Hi,
My company is spending a whole bunch on money on a server just to host
a very important download. It's not a single file. It's several files
where users download whatever part they need using our software client.


We're getting a Dual xeon 2.8 GHZ server with 2 GB ram and I'm not sure
what kinda drives to get. 2x73GB Scsi 10K RPM mirrored has been
recommended by some but they're tougher and much more expensive to get.
We can easily get 10K RPM Sata drives instead.

I hear they actually perform better in many cases. Would this be the
case for a download oriented server like ours?

I want to save the company money but if there is any significant
decrease in performance then I'm definitely obligated to bend over
backwards and go with the scsi.

Any comments/help would be greatly appreciated!
Click to expand...

You have to find out:
1. what is the approximate average download file size
2. how much (MB) of data will be downloaded per day
3. how many average concurrent downloads will occur
4. how users are connecting to the server (their slowest network link speed)
5. where server is located (ISP?) and how is it connected to users (speed
wise)
6. what downtime users will agree to tolerate (SLA)
7. do you have to provide redundant/alternate server, in case the first one
is unavailable?
8. do you have this service already in place and asking for an advise on
upgrade?

From what you have already said, I assume that almost any server will
suffice. Unless your users are not on Internet, but on a local LAN, and they
are very sensitive to extra milliseconds of download time.
 
justatech2004 said:
Hi John and thanks for the response.

Define "frequently" for me. It does change once every week or so but I
guess that's not a factor right?

And is 2GB ram sufficient? We have around a hundred people downloading
50 megs of data sometimes (usually 10-20)
Click to expand...

Are they all downloading the same 50 meg or will each be downloading a
different 50 meg? If they're all downloading the same data then unless
there's something you're not telling us 2 gig should be sufficient. If
they're all downloading a different 50 meg then that's up to 5 gig of data
alone and it's time to go for a 64-bit machine with a 64-bit OS and jack
the RAM up a bit.
 
justatech2004 said:
My company is spending a whole bunch on money on a server just to host
a very important download. It's not a single file. It's several files
where users download whatever part they need using our software
client.


We're getting a Dual xeon 2.8 GHZ server with 2 GB ram and I'm not
sure what kinda drives to get. 2x73GB Scsi 10K RPM mirrored has been
recommended by some but they're tougher and much more expensive to
get. We can easily get 10K RPM Sata drives instead.
Click to expand...

You're off to a great start with the dual Xeon. The 2 GB of RAM will
suffice for most applications and it's cheap if you need more. My
recommendation is to use either a pair of 73GB or 146GB (SCA) Seagate
Cheetah U320 SCSI drives instead of playing around with SATA or SATA2.
There's a reason why SATA is recommended, it's because it's cheap and the
data that one puts on it isn't important. If you're looking for great
performance and reliability you have only one choice and that's SCSI. My
recommendation for a good case with SCA bays is the Supermicro SC742S-500.
This is our main staple for bulletproof reliability.

http://www.supermicro.com/products/chassis/4U/742/SC742S-500.cfm
I hear they actually perform better in many cases. Would this be the
case for a download oriented server like ours?
Click to expand...

Again, if you are just building a novelty box for gaming then SATA will be
fine. If you are looking for bulletproof reliability and performance pay
the few bucks now and go SCSI. Remember, all SCSI drives aren't created
equally; we only use Seagate Cheetahs in all our systems we sell.
I want to save the company money but if there is any significant
decrease in performance then I'm definitely obligated to bend over
backwards and go with the scsi.
Click to expand...

It's cheaper to spend the extra money now on SCSI than it is to get egg on
your face when you have to explain why your wasting too many hours replacing
SATA drives and restoring data. Downtime is a hell of a lot more expensive
than a pair of SCSI drives.







Rita
 
Rita said:
It's cheaper to spend the extra money now on SCSI than it is to get
egg on your face when you have to explain why your wasting too many
hours replacing SATA drives and restoring data. Downtime is a hell
of a lot more expensive than a pair of SCSI drives.
Click to expand...

Agreed with all the rest, but...

Downtime replacing drives?
Hotswap and RAID are not novelties in 2005....
 
Mike said:
Agreed with all the rest, but...

Downtime replacing drives?
Hotswap and RAID are not novelties in 2005....
Click to expand...

Absolutely! Let's see him get a SATA solution working reliably and we'll
talk hotswap later. The solutions I mention will accommodate a hot spare so
he won't have any worries. Like I said, build it right the first time and
you will forget you even have a server since you won't be dicking with
substandard equipment. Being reminded your server needs attention costs you
money.





Rita
 
Rita you have hit this nail on the head!

Man, usenet is still one of the most useful resources the internet
provides even after all these years. I haven't contributed in years but
I think I'll start again. Only difference from '93 - a lady actually
had the best advice in a tech issue and it's GREAT to see!! Now that
was difficult in '93.

Long live usenet!
 
justatech2004 said:
Rita you have hit this nail on the head!

Man, usenet is still one of the most useful resources the internet
provides even after all these years. I haven't contributed in years but
I think I'll start again. Only difference from '93 - a lady actually
had the best advice in a tech issue and it's GREAT to see!! Now that
was difficult in '93.
Click to expand...

Actually, Rita's full of crap as usual. There's no trick to getting an SATA
hotswap array with hot spare working.

Rita's a classic example of of "if all you have is a hammer everything looks
like a nail".
 
justatech2004 said:
Rita you have hit this nail on the head!

Man, usenet is still one of the most useful resources the internet
provides even after all these years. I haven't contributed in years
but I think I'll start again. Only difference from '93 - a lady
actually had the best advice in a tech issue and it's GREAT to see!!
Now that was difficult in '93.

Long live usenet!
Click to expand...

Good luck and have fun! This is a great group to occasionally pick up some
useful information if you have time to weed out the trolls that spew
misinformation and block out the infighting between them.





Rita
 
J. Clarke said:
Actually, Rita's full of crap as usual. There's no trick to getting
an SATA hotswap array with hot spare working.
Click to expand...

LOL!! I see you're still mad because of that spanking I gave you a few
years ago and proved to the world how inexperienced you are? The original
poster is looking for a reliable solution for a *business*!!! He's not
looking to build a gaming machine that he wants to overclock and crash three
times a day. He's spending good money on quality hardware and you are
recommending that he use $49 bargain basement unreliable drives!!! Come
back when you grow up.
Rita's a classic example of of "if all you have is a hammer
everything looks like a nail".
Click to expand...

Yes, that's the difference between you and me. I use my "hammer" on the job
every day in real world situations. You, on the other hand, parrot mindless
statistics and specifications you read on Zdnet. Come back when you
actually did something physical.






Rita
 
Rita said:
You're off to a great start with the dual Xeon. The 2 GB of RAM will
suffice for most applications and it's cheap if you need more. My
recommendation is to use either a pair of 73GB or 146GB (SCA) Seagate
Cheetah U320 SCSI drives instead of playing around with SATA or SATA2.
There's a reason why SATA is recommended, it's because it's cheap and the
data that one puts on it isn't important. If you're looking for great
performance and reliability you have only one choice and that's SCSI. My
recommendation for a good case with SCA bays is the Supermicro SC742S-500.
This is our main staple for bulletproof reliability.

http://www.supermicro.com/products/chassis/4U/742/SC742S-500.cfm



Again, if you are just building a novelty box for gaming then SATA will be
fine. If you are looking for bulletproof reliability and performance pay
the few bucks now and go SCSI. Remember, all SCSI drives aren't created
equally; we only use Seagate Cheetahs in all our systems we sell.



It's cheaper to spend the extra money now on SCSI than it is to get egg on
your face when you have to explain why your wasting too many hours
replacing
SATA drives and restoring data. Downtime is a hell of a lot more
expensive than a pair of SCSI drives.







Rita
Click to expand...
You seem to be saying SATA drives are less reliable than SCSI.

Can you back that up with actual data, or is it just speculation
and prejudice?

My understanding is that in at least some cases the two use very
similar mechanisms, and only the interface is different. There's
no obvious reason (to me) why the SATA interface can't be made as
reliable as the SCSI interface, but I'll listen to reasons why
that might not be so.
 
Rita said:
LOL!! I see you're still mad because of that spanking I gave you a few
years ago and proved to the world how inexperienced you are? The original
poster is looking for a reliable solution for a *business*!!! He's not
looking to build a gaming machine that he wants to overclock and crash
three
times a day. He's spending good money on quality hardware and you are
recommending that he use $49 bargain basement unreliable drives!!!
Click to expand...

How about some support for that claim of unreliability?

Come
 
Ah the infighting. It truly is beautiful to see that nothing ever
changes around here. Thank god for that ;-)!
 
CJT said:
Rita Ä Berkowitz wrote:

You seem to be saying SATA drives are less reliable than SCSI.

Can you back that up with actual data, or is it just speculation
and prejudice?

My understanding is that in at least some cases the two use very
similar mechanisms, and only the interface is different. There's
no obvious reason (to me) why the SATA interface can't be made as
reliable as the SCSI interface, but I'll listen to reasons why
that might not be so.
Click to expand...

I have to say I also believe SCSI is more reliable than SATA.

However, properly cooled, SATA drives (provided you use the decent
brands (brand)) are generally reliable.

Not only that, but what with the recent arrival of decent PCIe drive
controllers (Areca, Broadcom, etc) speed is no longer a deciding factor
in choosing SCSI. Sorry, Rita - I've been a SCSI stickler for many
years, but I am now quite happy to use SATA. What with the hot-swap
capability of these controllers (and now with RAID 6, although I haven't
yet experimented with that) provided you have the requisite cooling and
redundant power supplies, etc, I can no longer see the reason for SCSI.

I recently took the decision to finally remove the SCSI drives from my
main computer and I haven't yet found myself sitting on the edge of my
chair, waiting for the drives to fall over.


Odie
 
Rita said:
Absolutely! Let's see him get a SATA solution working reliably and
we'll talk hotswap later. The solutions I mention will accommodate a
hot spare so he won't have any worries. Like I said, build it right
the first time and you will forget you even have a server since you
won't be dicking with substandard equipment. Being reminded your
server needs attention costs you money.
Click to expand...

Even the very chassis you recommend has a hotswap SATA version:

http://www.supermicro.com/products/chassis/4U/742/SC742T-550.cfm

RAID will take care of the "unreliability" of SATA drives compared to SCSI,
although I`m not convinced SATA drives are any less reliable than SCSI.

Even if they were, you can replace 2-3 SATA drives for the price of
one SCSI. RAID will ensure you have no data loss or downtime
when they fail, which is the whole point surely?

You may have a point with performance, as there are many 10k and
15k rpm SCSI drives available, SATA has just the 10k raptors.
 
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