SUMMARY: Sun Metadisk driver/SPARCserver Manager

From: fed!
Date: Tue Jun 04 1991 - 07:24:32 CDT

Thanks to everyone who has responded to my question about the Sun
Metadisk driver. The metadisk driver seems to be a working product
that does more good than harm, but one could imagine better. Better
in fact may be coming from Sun, something that I will look in to.

Thanks again,

Bob Drzyzgula
Federal Reserve Board

Responses were received from:

uunet!Canada.Sun.COM!tony (Tony Santos - Sys/Net Administrator Sun Toronto)
uunet!chron!magic706!sysnmc (Matt Cohen)
uunet!!torda (Andrew Torda)
uunet!!chris (Christopher Martin)
uunet!!dharmesh (Dharmesh Mehta)
uunet!!zjat02 (Jon A. Tankersley)

Original Query

A few inopportune hardware failures of late have caused us to do some
some re-evaluation of how we are approaching some "critical"
applications. We think that Sun's Metadisk driver (providing disk
mirroring), along with some creativity in hardware configuration, may
help with the availability of these applications.

Question: does anyone use this product? Is it a blessing, a mixed
blessing, or a curse? Is there anything better?

I will summarize if there is interest.

Bob Drzyzgula
Federal Reserve Board


they are supposedly starting a beta on a new product. So it is probably a
little of all three....


We use the package, but to get big concatenated partitions, so
I don't know if my comments are too relevant.

We notice
1. It works
2. It gives disturbing messages on startup and shutdown. The driver
    sneaks in as a process and doesn't die when init wants to change
    from single to multi user or back again.
3. As part of the sparcserver manager package, you also get 3 performance
   monitoring programs.
   They only work under sunview so, as MIT X users, we haven't played with
   them. Dammed annoying.


We have been using Metadisk to mirror file systems for over six months.
It works like a charm.


I'd be most interested in the reply. I had looked at metadisk early on
but it didn't at that time do mirroring across machines (just across disks
on the same machine). If that is no longer the case I'd be very interested
in a summary.


        We've been using Metadisk (I think the whole product is called
SparcServer Manager) since it was in Beta and have been very pleased with
it. We have used it on 4/280s and SparcStation 2s under SunOS 4.0.3 and

        I works pretty much as advertised and has saved us a lot of hassle
on several occasions. We had a slight compatibility problem with AFS, but
that might have been something else.

        I haven't heard of anything comparable, but I would be very interested
in what you find out.

        Our problem is that server crashes are an order of magnitude more
common than disk failures. I'd love to see a disk mirroring scheme/distributed
file system that mirrors disks on separate machines in real time with
transparent crash tolerance, but I think such things are still in the
research phase right now.

        You might want to take a look at the ISIS toolkit which makes it
easy to implement distributed, fault-tolerant applications - contact for more info.


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