cheap san was (E: [NTLUG:Discuss] File Size Limit)

Alfred Dayton linux at adayton.com
Fri Nov 21 14:38:14 CST 2003 

I just found possibly the answer.  Some numbers:

http://www.audiomidi.com/classroom/hardware/drives_2_ide.cfm
Throughput
Since the introduction of these drives specifications they have increased
the throughput of these ATA standards.
ATA/66
ATA/66 can be of any drive protocol but allows a maximum bust rate of up to
66MB a second. To implement ATA/66 your motherboard and your hard drive must
support ATA/66
ATA/100
ATA/100 just like ATA/66 can be of any drive protocol but can burst up to a
maximum of 100MB a second. To implement ATA/100 your motherboard and your
hard drive must support ATA/100. There are third party PCI cards available
that you can install on your computer that will allow you to run ATA/100
drives on your computer. These are very similar to SCSI cards and can also
be used in Macs.
This would seem to indicate that the present limiting factor is the Box B
ata66 drive subsystem.  So perhaps

the answer is to go with gb nics and switch with a new linux Box B with
either the new serial ATA or

Even the previous ATA 133??  disk drive subsystem.  In the interim perhaps
like the information indicates,

The purchase of a third party ATA 100 PCI controller card?

What arre your thoughts?

Alfred



-----Original Message-----
From: discuss-bounces at ntlug.org [mailto:discuss-bounces at ntlug.org]On Behalf
Of Chris Cox
Sent: Friday, November 21, 2003 11:11 AM
To: NTLUG Discussion List
Subject: Re: cheap san was (E: [NTLUG:Discuss] File Size Limit)

Alfred Dayton wrote:
> Speaking of "cheap mans san", I am trying to find method for xfer large
(25
> gig) video files off a
>
> Windows rendering workstation across network (10/100/1000) to a pc/san/nas
> device.  Perhaps
>
> Linux would provide a speedy solution???  The problem is it takes a
> Loooooong time presently
>
> Xfer from windows 2000 to windows 2000 boxes across a 10/100 mbs lan.
What
> are the limiting
>
> Factors in this scenario? I.e., would changing to 1 gig lan improve xfers
or
> is the bottleneck in

ABSOLUTELY!!  The network (100mbit) is slower than the disk performance by
a large factor.

You can do things to speed up local access... but in your case, the
network case... it's your network speed that is the bottleneck.

With regards to moving to a true SANS device.. that should be
fiber... so you should be ok there.

Now your SANS "network" and your IP network are two separate things
(ideally).
So it's conceivable that you have a gigabit NIC (possibly fiber ... could
be copper) and your SANS HBA controller (most likely fiber) in the same
box.  However, if it's just disk to host performance you need... then the
SAN HBA is the main thing... the gigabit NIC would be used just in the
transition (though nice to have if you are able to).

So... IMHO... if you have a true SANS disk array (Nexsan is good if
on the cheap).  Hook up your Windows or Linux box via a fiber HBA
device (this is NOT a NIC!) to the SAN (possibly though an intervening
fiber switch... which is generally what you need if multiple hosts are
going to use disks carved out of the SAN disk array).  Once you've
established your new SAN disk architecture... do a one time xfer to
the new SAN device and start working.  The SAN disks show up as
local SCSI drives.  You MUST have some education on SANS though... I'd
look at getting the SAN/NAS book from O'Reilly to start with (though
it does contain a somewhat serious error with regards to zoning security).

In general SAN will be faster, but more complicated and costly to setup.
You're looking at $500 for every HBA, your fiber switch could run
you $$$$ to $$$$$ depending on model (GBICs for ports on the switch
add to the cost... anywhere from $300 - $1000 per port), the cost of
fiber cabling is MUCH higher than copper.  If you go with an
"enterprise" class storage array... well... there's not enough room
for the $'s here (!!).

NAS is cheaper and easier to understand.  If you go the NAS route,
then I'd move to gigabit NICs.  I'm using the Intel 1000 FX boards
right now and I'm easily seeing 894Mbit host to host.  My experience
with the cheaper gigabit NICs is usually less than 600Mbit host to host.
But YMMV.

Of course if money is infinite... do both SANS and NAS!!

>
> The hard drive/pci bus area?  I googled and checked drive mfgs for some
kind
> of chart or
>
> White paper/faq on the subject matter but found none.  Compaq Server Div
> several years ago had an excellent
>
> White paper on this subject but I can not find it again.
>
>    I am guessing that a small hardware raid stripe (3-6 drives) on each
box,
> whether windows or linux is going

Striping has to do with throughput on a high speed bus... until
you eliminate the network (100Mbit) bottleneck.. this won't buy
you anything.

>
> To be the only answer to achieving realstic thruput to move the files in
an
> acceptably short time.  If so
>
> Since xfers are only intermittent perhaps software raid strip would work
to
> keep cost down.

Hmmmm.. I'm confused here.  "High speed" and "video" don't usually bring
to mind words like "intermittent".  I usually think of running
tasks generating gobs of data during that period of time.  Producing
25GB of data takes enough time even with lightning fast buses and
setups.

>
> Thanks for any help point me in right direction.

Get the O'Reilly book.  Using SANS and NAS by Curtis Preston.
I would do a lot of research/education before implementing/deploying.

>
> Alfred
>
> -----Original Message-----
> From: discuss-bounces at ntlug.org [mailto:discuss-bounces at ntlug.org]On
Behalf
> Of gan hawk
> Sent: Thursday, November 20, 2003 1:58 AM
> To: discuss at ntlug.org
> Subject: Re: [NTLUG:Discuss] File Size Limits
>
>
> The issue is not with file system alone. Applications need to support 64
bit
> addressing. Like if the application uses open() for reading files, it will
> not work and you have to use open64() or set O_LARGEFILE. I learnt this
the
> hard way when working on a progam to image computers.
> But you can file a bug with apache and they should fix it.
>
> Ganesh
>
>
>>some apps like apache will only work with less-than-2gb files. If your
>>apache log
>>files go over 2Gig the apache server will crash or stop logging... can't
>>remember
>>which.... so ever if the OS does large files... the apps might not.
>>
>>jack
>>
>>
>>
>>
>>>On Wed, 2003-11-19 at 16:26, Chris Cox wrote:
>>>
>>>>Kenneth Loafman wrote:
>>>>
>>>>>Has the 2GB file size limit been broken under Linux yet?
>>>>>
>>>>>If so, does it need a special kernel gen to get there?
>>>>>
>>>>>I'm thinking that it hasn't because size_t is still typedef'ed to an
>>
>>int
>>
>>>>>in many places, and that's 32-bit until we go to 64-bit processors.
>>>>>
>>>>
>>>>Uhhh... yep.. broke through this quite some time ago....
>>>># ls -lh
>>>>total 24G
>>>>drwxr-xr-x    4 root     root          256 Nov 14 13:50 .
>>>>drwxr-xr-x   25 root     root          600 Nov  3 16:32 ..
>>>>-rw-r--r--    1 root     root          84M Jul 16 10:05
>>
>>9_Recommended.zip
>>
>>>>-rw-r--r--    1 root     root         9.8G Sep  2 13:21
>>
>>celap5-suse82-30G-cjc.img
>>
>>>>-rw-r--r--    1 root     root         8.1G Sep 24 16:53
>>
>>celap7-suse82-30G-cjc.img
>>
>>>>-rw-r--r--    1 root     users        5.3G Jul 24 12:46
>>
>>rh90-n610c.img.gz
>>
>>>>I know I've created larger files... just an example.
>>>>
>>>>This is from a SuSE 8.2 box with a 1.7TB RAID 5 using
>>>>reiserfs out of the box.... no mods necessary with SuSE anyway.
>>>>
>>>>Samba has a "come and go" issue with 32bit limits... you'll need
>>>>to have both the latest samba 2.2.8a+ and the latest kernel smbfs
>>
>>patches
>>
>>>>for it to understand more than 2G (there are other versions of
>>>>Samba where it worked... it's just one of those things that
>>>>comes and goes).
>>>>
>>>>I'm working on getting our 1st 4TB RAID setup and working.  It's
>>>>split across two SuSE boxen (they can see each others stuff
>>>>when needed... sort of a cheap man's SAN).
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>_______________________________________________
>>>>https://ntlug.org/mailman/listinfo/discuss
>>
>>
>>_______________________________________________
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>
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