RAID

RAID

Post by Tim Arche » Wed, 10 Dec 1997 04:00:00



Has anyone sucessfully setup a RAID machine using Linux. I am looking
for a good hot swappable controller to setup a RAID1 (mirroring) setup
in my server. I would plan on using 2 9GB SCSI drives with some type of
RAID controller, but I am not sure as to a good controller which is
supported by Linux. I want the RAID to be done on the hardware level,
and possibly have a hot spare support so if one drive does crash it will
reconstruct the hot spare in the background.
Any thoughts would be greatly appreciated.
Tim Archer
Computer Technology Solutions

 
 
 

RAID

Post by John Thoma » Thu, 11 Dec 1997 04:00:00


www.dpt.com


> Has anyone sucessfully setup a RAID machine using Linux. I am looking
> for a good hot swappable controller to setup a RAID1 (mirroring) setup
> in my server. I would plan on using 2 9GB SCSI drives with some type of
> RAID controller, but I am not sure as to a good controller which is
> supported by Linux. I want the RAID to be done on the hardware level,
> and possibly have a hot spare support so if one drive does crash it will
> reconstruct the hot spare in the background.
> Any thoughts would be greatly appreciated.
> Tim Archer
> Computer Technology Solutions



 
 
 

RAID

Post by Dr. Ram Samudral » Fri, 12 Dec 1997 04:00:00



>Has anyone sucessfully setup a RAID machine using Linux. I am looking
>for a good hot swappable controller to setup a RAID1 (mirroring) setup
>in my server. I would plan on using 2 9GB SCSI drives with some type of
>RAID controller, but I am not sure as to a good controller which is
>supported by Linux. I want the RAID to be done on the hardware level,
>and possibly have a hot spare support so if one drive does crash it will
>reconstruct the hot spare in the background.

Check out
<http://www.ram.org/computing/linux/dpt_raid.html>

--Ram


  Person man, person man. Hit on the head with a frying pan.
  Lives his life in a garbage can. Person man,
  is depressed or is he a mess? Does he feel totally worthless?
  Who come up with person man? Degraded man, person man.
                           --They Might be Giants,  Particle Man

 
 
 

RAID

Post by Kit Cosp » Fri, 12 Dec 1997 04:00:00



>www.dpt.com


>> Has anyone sucessfully setup a RAID machine using Linux. I am looking
>> for a good hot swappable controller to setup a RAID1 (mirroring) setup
>> in my server. I would plan on using 2 9GB SCSI drives with some type of
>> RAID controller, but I am not sure as to a good controller which is
>> supported by Linux. I want the RAID to be done on the hardware level,
>> and possibly have a hot spare support so if one drive does crash it will
>> reconstruct the hot spare in the background.
>> Any thoughts would be greatly appreciated.
>> Tim Archer
>> Computer Technology Solutions


        There are a couple of options here.  As mentioned above, DPT has
some RAID controllers that work well under Linux.  However, the last time
we took a look at them you had to boot into some other so-called operating
system to run the recovery utility.  It has been a while since we investigated
DPT, so this may have changed.  Last year at Comdex some of the DPT folks
claimed that they were working on porting the utility to Linux, but repeated
attempts to get more information have not produced anything.  

        We have delivered several systems outfitted with RAID that use the
Mylex DAC-SUI SCSI-SCSI RAID controller.  This is a unit about the size
of a full-profile hard drive (fills 2 "standard" drive bays on today's
chassis) with an LCD panel and a set of buttons.  The kernel simply sees
one SCSI device (the Mylex) and the RAID controller handles all the
communication and monitoring of the drives in the array.  It supports
RAID 0-5 as well as what Mylex calls "JBOD" (Just a Bunch Of Drives)
which allows you to cluster assorted drives into one large device.
All recovery is initiated on the control panel, or the Mylex has a serial
port that you can use to access the controls.

        This is *not* an inexpensive solution, but it is highly reliable
and works well.  Expect to spend something in the neighborhood of $2200
for a 2 channel DAC-SUI with 8 MB cache.  Hot swapping is not a problem
with this setup, since the kernel doesn't even know what drives are
physically present in the array.  It's quite entertaining to watch the
expression on someone's face when you power down a drive in the middle
of a kernel build and the machine doesn't miss a beat.  :-)

--Kit

 
 
 

RAID

Post by Dr. Ram Samudral » Fri, 12 Dec 1997 04:00:00



>physically present in the array.  It's quite entertaining to watch the
>expression on someone's face when you power down a drive in the middle
>of a kernel build and the machine doesn't miss a beat.  :-)

The DPT controller is certainly capable of doing that (well, we had a
disk crash and it was hotswapped without problems).  Also, you can run
the DPT manager under DOS emulation.

Not to say DPT is the best solution, but my understanding is that
SCSI-to-SCSI controllers aren't as good has host-based controllers.  

The only expensive thing about DPT is their how-swappable enclosures!
Anyone know a good alternative to these?

--Ram


"Things fall apart; the centre cannot hold;
 Mere anarchy is loosed upon the world" --W.B. Yeats, The Second Coming

 
 
 

RAID

Post by bill davids » Sat, 13 Dec 1997 04:00:00




| Has anyone sucessfully setup a RAID machine using Linux. I am looking
| for a good hot swappable controller to setup a RAID1 (mirroring) setup
| in my server. I would plan on using 2 9GB SCSI drives with some type of
| RAID controller, but I am not sure as to a good controller which is
| supported by Linux. I want the RAID to be done on the hardware level,
| and possibly have a hot spare support so if one drive does crash it will
| reconstruct the hot spare in the background.

Take a look at CORE arrays. They are relatively inexpensive, have
cache, rebuild on the fly, hot swap, all that good stuff.

With dificulty I refrain from pointing out the RAID-1 stuff already
in the kernel, since you insist on hardware implementation. There is
RAID-5 stuff in the development kernel, if your data grows (as it
has a habit of doing).
--

  What do you mean I shouldn't do thing like that at my age? At my
age if you don't do things like that you might die of natural
causes or boredom!

 
 
 

RAID

Post by Jason A. Ramse » Wed, 17 Dec 1997 04:00:00


Mylex, Mylex, Mylex...Comes with Linux Drivers (a good sign), has really
(and I mean really) fast cache (10ns ED RAM), and runs circles around any
other *affordable* RAID solution.  I personally recommend the DAC960i, 2
channel (for mirroring) or 3 channel (for RAID anything-else).

--
Regards,

Division Manager
Connektech             <http://www.tweedinc.com/connektech>



>>physically present in the array.  It's quite entertaining to watch the
>>expression on someone's face when you power down a drive in the middle
>>of a kernel build and the machine doesn't miss a beat.  :-)

>The DPT controller is certainly capable of doing that (well, we had a
>disk crash and it was hotswapped without problems).  Also, you can run
>the DPT manager under DOS emulation.

>Not to say DPT is the best solution, but my understanding is that
>SCSI-to-SCSI controllers aren't as good has host-based controllers.

>The only expensive thing about DPT is their how-swappable enclosures!
>Anyone know a good alternative to these?

>--Ram


>"Things fall apart; the centre cannot hold;
> Mere anarchy is loosed upon the world" --W.B. Yeats, The Second Coming

 
 
 

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