SUMMARY: Advice on purchases for a server

From: Bill Hart (Bill.Hart@ml.csiro.au)
Date: Wed Aug 26 1992 - 17:56:43 CDT


Many thanks to those who responded with advice and opinions. My original
question was :-

>
> Hi,
> I have very limited funds to spend on setting up or upgrading a
> nfs server for a network of (~15-20) suns (SS2,IPX,SS10(soon),SS1,IPC,ELC
> all with local disk). The server basically provides read only access to
> software (X11R5/openwindows, gnu stuff etc, etc), cdrom and optical disk,
> using amd 5.3.
>
> Currently the machine serving this function (a SS2 32MB with a Wren
> VII) is also used for number crunching, (which is why for political
> reasons I have to switch these services to another machine) response at
> the moment is not brilliant, but it is quite acceptable most of the
> time. The SS2 ethernet performance is not great and this is probably
> the area where most improvement could be made.
>
> There appear to be two options I can afford:
>
> 1/ Upgrade a SS2 to a SS10-30 or SS10-41 and add a couple of FAST SCSI-2
> disks (Wren VIII's ? are Wren VII's capable of this ?) (This machine
> would also have to be used for number crunching)
>
> 2/ Buy a IPX and add a FAST SCSI/Buffered Ethernet (FSBE/S) card part no
> X1053A (does anybody have any experience with this card). (This would
> sit on my desk and be dedicated to the network except for building and
> testing software).
>
> There doesn't seem to be much point in using a Prestoserve card as
> virtually no nfs writes are being done, and these cards are only really
> effective on nfs writes.
>
> It seems to me that the effectiveness of a server of this type is
> dependent upon the ethernet performance rather than the disk performance,
> is this correct ? So will the two configurations give equal performance
> or will one be signifigantly better ?
>
> Any advice would be much appreciated (I am being pressured to place an
> order in the next few days and don't have a chance to test any of this
> stuff myself (anybody actuall seen a SS10 ?)).
>
The general recommendations were :-

1/ Subnet if you can (single ethernet performance is not really an
issue). (unfortunately not really feasible for me, everything is
spread out over 5 buildings, and of course the computer room is at
one end of the network, it would involve laying new cabling etc etc...)

2/ SCSI transfer rates are not really an issue (unless you have a lot
of disks on the bus). It is more important to get disks with fast
seek times rather than disks with fast transfer rates as NFS is primarily
a random access activity.

3/ Load the system up with as much memory as you can (helps caching for
clients).

4/ Cpu performance for serving is not really an issue unless you have
multiple ethernets.

5/ It was generally recommended to seperate the number crunching from
the file serving functions (although one respondent said that this
could be used to lever future funds from those above).

6/ Tune the file server

Or to quote cal@soac.bellcore.com

>1) dedicate machine to NFS and eliminate ALL other activity.
>2) add as much memory as you possibly can since SunOS caches everything
>3) extend cache timeouts on mounts to reduce client cache update requests
>4) set MAXUSERS to 128 to increase inode cache, etc.
>5) incrementally increase number of nfsd's (+= 4).
>6) add the fastest disks you can afford.
>7) add an NC400 (this is VME based so probably not much help).
>8) segment network & add multiple ethernet interfaces.

Of the 15 who responded

SS10 5
IPX 5
Abstain from making a recomendation 5

It doesn't appear that the SS10 is going to fullfill this function a
whole lot better than a IPX. I'm inclined to go for the IPX, buy the
fastest disk I can and add as much memory as possible. My reasons :-

a) Political, individual groups here buy their own machines (they can go
and buy SS10's if they want) it would make my life a whole lot easier,
not to have to negotiate to provide services from a particular machine.

b) Nobody has tried the buffered ethernet/scsi board yet (as I'll only
have 2-3 disks it's not apparrent it will work better with 2 scsi boards
or that ethernet performance will be improved - maybe next year).

c) The response to clients will be about the same for both configurations.

d) It's rummoured that it will be possible to upgrade an IPX to user
SuperSPARC sometime in the future anyway (I'd be real surprised if sun
don't do this sometime in the future).

Thanks again to all those who responded with some excellent advise

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bill Hart Internet : hart@ml.csiro.au
Network Manager Phone : +61 02 206 442
CSIRO Division of Oceanography Fax : +61 02 240 530
Hobart, Tas., 7000 Australia Paging: +61 08 001 234 (quote #29474)
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