[OpenAFS] sanity check please.

Pucky Loucks ploucks@h2st.com
Mon, 5 Sep 2005 08:24:37 -0700

Thanks so much for you response Lars, I've commented below.

On 4-Sep-05, at 4:01 AM, Lars Schimmer wrote:
> | 1) Is this going to become a huge management issue?
> Depends.
> If you use some nice scripts, it could be managed easy.
> At all its just kinda "vos create volume" "fs mkmount path volume" "fs
> setacl path rights" and "backup volume". And after all, the big =20
> overview
> ;-) As long as you manage your cell well enough, it=B4s easy. Please =20=

> don=B4t
> create one dir with all volumes in it.
am I correct in that a volume isn't replicated until a "vol release" =20
"fs checkvolumes"? i.e. as I write new images I'll need to decide =20
when I should run those commands?  I might just end up replicating it =20=

at the end of the day. for 1/2 day.

> | 2) If I end up getting 5 thousand images a day would I want it to =20=

> be  in
> | it's own volume so I could replicate each "day"?
> What do you mean "images"? CD images? DVD images?
jpeg images. small ones.  i.e. between 50kb and 300kb. also we'll be =20
storing 15 second video clips and audio clips approx 350kb

> You can create one volume for each day, for each 5000 images. But =20
> think
> about: 5000 images in one directory is a real mess to search through.
> And if that are "big" images, the size of this daily volume grows =20
> fast,
> so a replicate volume takes far more time. Replication is near line
> speed (as long as there are no large amounts of small files >1kb; but
> you talk about images, so that files should be larger), but e.g. =20
> 100 gig
> in a volume takes its time to replicate at 100Mbit.
> I suggest 50 volumes a 100 images/day, e.g. numbered "day.001.01" or
> else, as you can find the volume easy and you can easy replicate them
> with a script. And if you distribute these volumes over 5-10 file
> servers, the replication process span over the network and is faster
> ended at all. Speed is a question of design.
this sounds like a good idea.  all of the logic of what file is =20
located where is in my applications database so I won't really need =20
to search from the command line for a file.

> | 3) what's the recommend max size for a volume?
> I once worked with 250 GB volumes. But to replicate these big =20
> volumes suxx.
good to know that you used such a large volume, even if it was really =20=

slow for replication
> And there is limit in files in a volume: max. 64k files with <16 =20
> letters
> allowed in one volume.
> ~=46rom a mailinglist-entry:
> The directory structure contains 64K slots.
> filenames under 16 chars occupy 1 slot.
> filenames between 16 and 32 chars occupy 2 slots
> filenames between 33 and 48 chars occupy 3 slots, and on
this part confuses me, do you have the link to the original topic?

> And please be aware, big file support (>2 GB/File) was introduced in
> 1.3.7x of OpenAFS.
> | 4) These files will be served via apache is that an issue? (my
> | understanding is it's not)
> As far as openafs.org runs from openafs in a apache, I assume not.
that's what I thought

again thanks so much for you help.  I ordered the book Managing AFS =20
from Prentice Hall yesterday. Hope it's a good read. :)