| Jim,
Actually, I do *not* want to do this. I just cannot find anything
anywhere saying I can't.
Here's the background:
Customer has an A2100A server. They have two internal SW shelves. One
is a split bus with first bus going to I/O module controller. The
second bus is unused. The other shelf is single bus connected to a
KZESC Swxcr 3 channel controller populated with all RZ28x-VA drives.
They are configured as a seven member (6 data + 1 parity) Raid 5 set.
This Raid set is getting too small. And, they want 'wide' SCSI type
disks.
They want to increase their disk capacity and speed (mostly capacity).
I have suggested going to a KZPSC-BA (or -AA) and an external shelf
(BA356-KC) populated with RZ29B-VW disks for a large Raid set. We
would then have two Raid sets and a third "4 member" bus available for
expansion from the existing split bus shelf. The reason I spec the -BA
controller is that they can then add 'wide' drives to the system on
different channels as needed and gradually phase-out the Eisa Swxcr
module.
However,they want to 'try' to utilize the internal shelf that now houses
only one disk (NT system disk).
Therein lies my problem. I need to be able to say that doing what is
described in .0 is *not* supported. I am an ex-field engineer. In
speaking with a member of support (also an ex-FE) he mentioned he had
seen a customer with an RZ28 in an internal drive bay on the
rack-mounted A2100A Server. I have found a grommet kit for mounting RZ
drives, but again, I am very leary since these type of drives are
not on the supported drives listing.
Any help appreciated...
Best Regards,
John Malott
|
| Well, keep in mind that the rackmount 2100 system is totally different
than the pedestal 2100. In the case of the rackmount version, you are
fully expected to mount drives directly inside the chassis (these are
orderable as the -EJ variants). So, it's a bad assumption that just
because the 2100R can take them that the regular 2100 could too.
I think there are some better ways to accomplish what you are trying to
do. First of all, note that your system disk does not *have* to be on
the internal SCSI bus; it could just as easily be on the EISA Mylex
controller. Secondly, is your EISA RAID controller a one-channel
controller only? If not, you could always cable a spare bus from there
to the other side of the split shelf.
Are your internal shelves the old style or the new style (i.e. wide
capable)? I would suspect they are new style if it is an "A" box. Why
wouldn't you add a KZPSC-BA, use two busses to go an external split
BA356 and cable the third bus internally to the shelf that is now split
but in single-bus mode? Then you could have your one existing drive and
six more in that shelf.
Jim
|
| Jim,
I agree with your idea of going to the KZPSC-BA. But, can I split a
Raid set among channels (it has been over a year since I've been into
these)? For example, if I put the one existing single bus shelf and
add'l one side of split bus. I just want to understand my options. I
also agree with going to the external shelf as well. This will allow
them to:
1. Keep existing Raid set on EISA Raid controller in tact.
2. Cable external shelf to PCI Raid controller channel and use other
channel(s) for future growth.
3. Cable either the unused side of the internal split shelf to the PCI
Raid controller or reconfig that shelf to single bus and cable that to
the PCI Raid controller.
Also, can I house a Raid set on the same bus as the system disk, but
not have the system disk be a member (ie, your idea of putting system
disk on KZESC, which is 3 channel BTW)?
Aren't there some considerations about placing an NT system disk on a
KZESC controller?
At any rate, I would like to indicate that placing the system disk
(RZ28M-EJ) in an internal drive bay is not a supported option.
Is this a correct position?
Thank you in advance...
Best Regards,
John Malott
|
|
> I agree with your idea of going to the KZPSC-BA. But, can I split a
> Raid set among channels (it has been over a year since I've been into
> these)? For example, if I put the one existing single bus shelf and
> add'l one side of split bus. I just want to understand my options. I
Yes, a RAID set can consist of members that physically reside on different
busses and in different enclosures (i.e. disks inside a Sable shelf and in
an outside BA356).
> Also, can I house a Raid set on the same bus as the system disk, but
> not have the system disk be a member (ie, your idea of putting system
> disk on KZESC, which is 3 channel BTW)?
Well, there are two answers to this. First of all, you can create one drive
on the RAID controller to be a JBOD and would appear as a single disk like
what you are used to. However, note that an existing drive on the internal
SCSI bus is not transportable to the bus on the RAID controller.
The second point to be made is that, since your system disk is probably your
most crucial disk on the system, it makes the most sense to have that disk
as a member of a RAID set, instead of being just standalone. This by the
way is a strength of the Mylex in an AlphaServer; there are no boot
restrictions. You sometimes see this on other products where the boot disk
is separate from the data disks; this is not optimum, it is just a result
of the RAID controller not supporting booting.
> Aren't there some considerations about placing an NT system disk on a
> KZESC controller?
There used to be. Way back when, there were minimum versions of firmware,
OS, and SP's, etc. that were required. Unless you're using some really
old stuff, you should have no issues. But check the versions.
> At any rate, I would like to indicate that placing the system disk
> (RZ28M-EJ) in an internal drive bay is not a supported option.
> Is this a correct position?
I'm not Engineering so don't quote me, but I think this is correct.
Regards,
Jim
|