EV 8 Fingerprint Database - Vague Info

[RHLLC]

I'm setting up EV 8 and I'm at the selection for the fingerprint database configuration for SIS.  The problem with Symantec documentation is it's so vague about sizing.  Here's a section from the online help:

"The non-primary filegroups may grow very rapidly in size. For optimal performance, specify as many locations as possible on the SQL Server, up to the maximum of 32. Each location should be on a separate device. If you specify more than one location on the same device there is no performance benefit."

What exactly does that mean?  What does "may grow very rapidly in size" mean?  100MB per minute?  1GB per week?  Fill an entire SAN in two years?  How can I even begin to add LUNS to my SQL box if I don't know what to expect?  Do I add 32 20GB LUNS, 32 100GB LUNS, or a 500GB LUN with 32 mount points?  I would assume that in the testing leading up to the release of the product and the writing of the help file that there would be some sort of guideline, but in typical fashion, I'm left scratching my head because I'm sure the answer, like every other answer about sizing EV is, "it depends".  Sheesh!

[Frank_Beck]

Have you had a read through the performance guide?

ftp://exftpp.symantec.com/pub/support/products/Exchange_Mailbox_Archiving_Unit/312319.pdf

In the calculating disk space section, there is a section on the fingerprint database (as well as other databases):

To calculate the space used in the fingerprint database:

1. Take the number of items archived.

2. Divide by 5.

3. Divide by the average number of sharers of each shareable item (2 if unknown).

4. Multiply by 500 bytes.

There are no additional entries in the database if mailbox archiving takes place after the items have been journaled within the sane Vault Store Group, if the mailbox and journal partitions participate in sharing.

[RHLLC]

Frank,

Thanks for the info; however, as a company new to EV, this information, while helpful, doesn't answer the question.  This is telling me how to calculate the space used by the fingerprint database based on the number of items in the archive.  Since this is a new install, there is nothing in the archive, so I can't calculate how much space to allocate for this.  I suppose I can count e-mail messages on the mail server, and get a file count from the file servers, and start chunking out some math, but giving a guideline based on something is better than saying "it will grow rapidly".  I just think it would be helpful to give some kind of starting number or growth factor, as long as I know that based on certain conditions, my mileage may vary.

We run an HP EVA SAN, so spreading the data out isn't an issue because of the way the EVA virtualizes across all disks.  To this end, I'm going to start by adding a 40GB drive to the SQL server and make 32 directories for the database to use for it's locations.  If I need more, I'll expand the drive.  We'll see how it goes...

[EV_Guru]

The calculations from the performance guide will help you when you calculate how must data you will have in your archive after your archiving policys happend and you archived everything from your Exchange backlog.

1. Take your Exchange data now and calculate how much data will be archived

2. Then you get an integer of data which is in the archive

3. Based on that you can calculate the Fingerprint Database with the Performance Guide

4. Then you have the amount of the Fingerprint Database and the growth level

The real growth level you can then calculate based on your Exchange growth level...

_________________

www.longerich.com

[RHLLC]

Thanks Guru.  I'll take a spin through that doc and see what I can come up with.

One more thing on the fingerprint database: why is the default setting to grow in 1MB increments across each of the 32 file locations?   Doesn't that cause considerable database fragmentation for something that is known to "grow rapidly"?  Is the only way to change that to go through each of the file locations and set them to say, 20-25MB?