[K12OSN] 8 Minutes to Open Open Office 2

[Les Mikesell]

On Wed, 2005-09-28 at 14:57, Petre Scheie wrote:
> Ok, here's a strange bit of info, perhaps worthless: I installed 4.4.1, complete with 
> OOo 2, on a new server a few weeks ago.  Server is Athlon 64 with 1GB RAM, serving 3-5 
> clients.  In the lab, before rolling it out to production, I clicked on OOo and it took 
> about 30 seconds to load, worse than the 4.2.1 with OOo 1.1.4 that had been on the 
> machine.  What a disappointment, since the whole reason I went to 4.4.1 was to get OOo 
> 2.  Tried it a several more times, hoping to build up the cache, but to no avail. 
> Logging in at the server and loading it made no difference for the clients.  Depressed, 
> I went to bed for the night.  The next day, I tried it again from a client: it loaded in 
> 2 seconds!  It's been snappy ever since.  I've had a few reboots since then and even 
> after that it still loads in less than 5 seconds.
> 
> I have no idea what the initial problem was, nor do I know what fixed it. Disk issue? 
> I've got just a single IDE disk in the server. But whatever it was, I can see how 30 
> clients hitting it simultaneously might drag out to eight minutes.

What is supposed to happen is that when you access a disk file the first
time it is loaded into memory cache with some read-ahead so if you read
it slowly, the next part you need is already there by the time you
access it. With a fast CPU and IDE drives you'll be waiting on the disk
anyway, but the point is that once it hits the cache it stays there
until something else needs the space.  The next access to the same file
(indexed by inodes so hardlinks are all the same) comes directly out
of the memory cache if it is still there. You'll also be opening the
files that hold personal preferences at the same time.  If these end
up flushing the OOo program out of the cache, then you have the disk
head trying to be in 30+ places at the same time.  (It helps to have
/home on a different drive, if not a different server...).

-- 
   Les Mikesell
     les at futuresource.com