filepro RAM limit

[Brian K. White]

----- Original Message ----- 
From: "scooter6" <scooter6 at gmail.com>
To: <filepro-list at lists.celestial.com>
Sent: Friday, May 11, 2007 9:28 AM
Subject: filepro RAM limit


>I have a customer who is running filepro 5.0.09R4 on a SCO OpenServer
> 5.0.5platform --
>
> Hardware is a Dell Poweredge Server - 2.4GHz processor
>
> Everything has been working great for about 3 yrs now -- I decided to
> upgrade their RAM -- they only had 512MB -- so, I'm at client's site --
> ordered 2GB from Dell and installed it last night -- everything booted 
> fine
> and ran a couple of processes last night - including some indexes - and it
> seemed a bit faster - just not REALLY faster like I would have thought --
>
> During their series of night time processes that runs nightly, it wasn't 
> any
> faster at all to complete -- still takes about an hour and a half ???
>
> Anyone have any suggestions on why the filepro processes wouldn't be
> noticably quicker to run ???
> Thanks
>
> Scott Ullmann

1) osr 505 does not auto-tune very much to take advantage of more ram. Some 
things adjust automatically many do not. Of particular interest to you in 
this case is the disk cache does not increase unless you increase it in 
/etc/conf/cf.d/configure. it can only go as high as about 450 megs, and you 
want to becareful setting it very high because that just makes every disk 
flush that much more painful. There are other settings in there for 
controlling how often the flusher runs and how old a given bit of data is 
allowed to get before it is flushed. The optimal settings are dependant upon 
each other, dependant upon your disk subsystem hardware, and a little bit 
religion/philosophy.

2) filepro's biggest bottleneck, especially on SCO, is disk I/O not cpu or 
ram, although ram can help with disk i/o via caching, but caching can't 
actually take the place of disk i/o, it just halps a little. Somewhere 
somehow the data must actually be read and written. Optimization of the 
order of reads/writes and removing some transactions only goes so far. The 
reason "especially on SCO" is because it's a known measured simple fact that 
sco's filesystem is between 1/2 and 1/5 the speed of everyone elses (linux, 
freebsd, even windows). There were some supposed performance enhancements in 
506, and then more in 507 with one of the patches, but I have all those and 
even 507 with the performance patch is still much slower than the rest. The 
only real help, other than switching to linux or OSR6 (I do not recommend 
osr6)
is to brute force increase the speed of the disks via hardware.

So what kind of disk subsystem is in the box?
scsi? u320 or slower? (certainly slower on a 505 box)
raid? what level? how many spindles? (more disks = more throughput  and more 
ability to jump around and do lots of things at once = faster)
cache on the raid controller? (if so then the os cache mentioned above is 
less important and might even be better to have a small os cache that 
flushes more often and let the card do the real caching.)

Also obviously make sure you aren't expecting fast reports at the same time 
the nightly tape backup is running. You can help that somewhat by putting 
the tape on it's own scsi card, but it probably already is.

You might not get that much improvementy even with a great raid card and 8 
disks in the existing box though because a 505 box probably ha s a 
motherboard with no high speed pci slots. A regular pci slot can only pump 
about 300mbit,  so get a u160 card on ebay and some disks from wherever 
(probably not ebay for the disks) You could get all new stuff if you figure 
on saving it for a new server shortly.

I don't claim this is a viable choice for you right now, but if it were me I 
wouldn't put much into it. I'd tell'm if they switch to linux it'll be a lot 
faster and put'm on 3 or 4 sata drives maybe using the purely software raid 
and the built-in motherboard sata ports. (you have the cpu to burn, it's 90% 
idle all the time) But, I can say that only because I have all the linux 
kinks worked out for our application already. The initial move to linux is 
somewhat painful. I was already well comfortable in linux before I started 
and I did it on test boxes and had it all worked out before doing a 
customer. I do not say "just install linux" the way a lot of idiots do on 
the newsgroups who apparently never saw 15 year old application in their 
life.

Brian K. White    brian at aljex.com    http://www.myspace.com/KEYofR
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