Dell PowerEdge 1600SC Server

[Vivek Khera]

On Jun 2, 2004, at 5:27 AM, Keith Farrar wrote:

> You might want to reconsider the PERC controllers offered with that 
> hardware. They (PERC3/SC and PERC4/SC) use the amr (megaraid) driver, 
> and we've had serious stability problems under FreeBSD 4.9 and 5.2.1 
> with that controller

I'll counter this remark with a "works great here".  I have a rack full 
of Dell boxes with various Dell PERC controllers running FreeBSD 4.8 
and up.  Some are amr devices, and some are aac devices.  All work 
flawlessly under quite substantial loads.

You should make sure you configure the RAID cards properly, too: 
write-back cache and turn off the adaptive read-ahead (use normal 
read-ahead).


> The systems (Dell PowerEdge 2650, 2 x 2.8 GHz) were fairly stable when 
> restricted to 2 GB of RAM and the internal RAID tray (using a PERC3/DI 
> and the aacraid driver).

Counter point: server in production since December 2003 (in testing for 
two months prior to that).  It is a 2650 2x2.4GHz Xeon, 4GB RAM, amr 
controller with two channels, one with a RAID0 pair, and another with a 
14 disk RAID5.  Controller identifies itself as PERC 3/DC.

This box runs a postgres database with about 40Gb of data (including 
indexes, etc.) on the RAID5.  It is in constant heavy use logging usage 
data, and generating usage summary reports, keeping track of user 
subscriptions, and other administrative tasks.

It has been down for exactly 10 minutes since December, and that was 
this past weekend for a scheduled upgrade to FreeBSD 4.10, and postgres 
7.4.2.

> The instability was a serious, but survivable, problem.
>
> Unfortunately, we need multi-terabyte NFS file service from our Dell 
> servers, but FreeBSD's rpc.lockd dies routinely, which is a 
> showstopping bug.

Does rpc.lockd even do anything in 4.x?  Oh wait... it only does the 
server side, not the client side of locking.

> So, sigh, we probably will deploy our boxes with Linux 2.6 kernel 
> distributions, as much as we would prefer to administer BSD boxes.

I'd recommend running Dell's diagnostics to see why you're having 
problems; it certainly isn't FreeBSD's fault, aside from your rpc.lockd 
issue.

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Vivek Khera, Ph.D.                Khera Communications, Inc.
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