HP Netserver 5/60 LM, SCO Openserver 5 and RAID

HP Netserver 5/60 LM, SCO Openserver 5 and RAID

Post by Bjorn Lin » Sat, 23 Mar 1996 04:00:00



We are thinking of using one of our HP-Netservers as a pure fileserver with RAID 0 or RAID 5 running SCO Openserver 5. The question is whether we shall (can?) use the onboard Adaptec 2740 Twin-channel hostadapter with a set of 3  4 GB high  perfomance SCSI-disks and SCOs Virtual Disk Manager, or rather buy a external RAID of some sort(Mylex ieg). Any experience or opinion on the issue is of interest.

Bjorn Lindi
Alcatel Telecom Norway
Message Handling Systems

 
 
 

HP Netserver 5/60 LM, SCO Openserver 5 and RAID

Post by Stephen M. Du » Sat, 06 Apr 1996 04:00:00


$We are thinking of using one of our HP-Netservers as a pure fileserver with RAID 0 or RAID 5 running SCO Openserver 5. The question is whether we shall (can?) use the onboard Adaptec 2740 Twin-channel hostadapter with a set of 3  4 GB high  perfomance SCSI-disks and SCOs Virtual Disk Manager, or rather buy a external RAID of some sort(Mylex ieg). Any experience or opinion on the issue is of interest.

   Please use your Return or Enter key _before_ you reach 80 chara
cters.  Otherwise,
your article becomes very difficult to read.  If it is very diffic
ult to read,
then people are less likely to read it.  If less people read it, y
ou are not
as likely to get the responses you desire.

   My purely opinionated take is that RAID is best done in firmware,
not in the OS.  That means a dedicated RAID controller card.

   Somewhere, there has to be a CPU running some code which implements
RAID.  Put it on your main CPU, and it burns some additional quantity
of CPU cycles.  If you've nothing better to do with those CPU cycles,
then it doesn't matter - but if you _could_ be putting your CPU to
use doing something else, then you're better off using a CPU that's
embedded in your RAID controller card, where you really don't care
about CPU utilization so long as the job gets done.

   Somewhere, there has to be a bus across which additional read/write
data is generated (to write to parity drives etc.) during normal
operation.  If you use software RAID, that bus is your system's
main I/O bus.  Again, if you have plenty of spare I/O cycles,
then it doesn't matter whether they're on your system's main I/O
bus (apparently, an EISA bus in your case).  And again, if
there's something better you could be doing with your I/O bandwidth,
then allow that bus to be on the far side of your RAID controller
card, and have only the actual data going across your main
system bus.

   That's my take on it - whether it's SCO Virtual Disk Manager,
mirrored drives under NetWare, the built-in RAID support in NT,
whatever.  Push the extra load onto a dedicated piece of hardware
rather than making your main CPU and I/O bus do it all.
--

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Stephen M. Dunn, CNE, ACE, Sr. Systems Analyst, United System Solutions Inc.
104 Carnforth Road, Toronto, ON, Canada M4A 2K7          (416) 750-7946 x251