On Sat, 17 Apr 1999, Dietmar Stein wrote:
Hi,
> Hm , I have not the possibilty to set up a hw-raid and mostly not the
> time to do so in order for testing and comparisons, but I have a
> suggestion towards hw- and sw-raids.
> I am using sw-raids on systems like you described with just more RAM and
> controllers on it running linux-2.0.36 (will switch to 2.2.x next days).
> We also got workstations and servers from HP with connected raid-systems
> (raid5). The systems are almost machines with two PA-RISC processor and
> 1GB RAM and above. The speed of the so called disk-arrays on the HP
> machines is very low. Based on UW-disk the only produce a "throughput"
> at roundabout 5 MB/s.
mmm... None of any HP machine I've ever met has surprised but
dissapointed me regarding it's performance, not to mention it BIOSes...
> The cause seems to be the integrated raid-controller, which works at 40
> or 50 MHz and calculates the checksum of the incoming data.
> The sw-raid of the linux-machines I use is much more faster even on a
> P166 or P200Pro (single processor) and of course on the double PII-400 -
> the lx-machines cost a fraction of the HP and redundancy is also given;
> also, the hw-raid controllers for Intel based PCs are much more
> expensive than normal SCSI-controllers and I think they are also slower
> than the sw-raid because of the CPU-speed which is responsible for the
> speed of the sw-raid.
> This is just a suggestion and a very subjective point of view - I know -
> but theory and practice are very close.
Yes, the theory is sound, that's why I ask for benchmark scenarios
and specific tests suggestions, that way, people like you, that knows the
ins of the Linux raid code but doesn't have the time or spare hardware to
do tests, can tell me "do this with that and that settings and this setup
in a scenario like this..."
greetings,
*****---(*)---**********************************************---------->
Francisco J. Montilla Systems & Network administrator
[EMAIL PROTECTED] irc: pukka Seville Spain
INSFLUG (LiNUX) Coordinator. www.insflug.org - ftp.insflug.org
