Large volumes

[Craig_Everhart@transarc.com]

Excerpts from mail: 10-Dec-01 Re: Large volumes David M. Karlsen at davidka
(1866*)

> Will replication be a problem? Let's say I had three diffrent volumes 
> /afs/{a,b,c} - to a total amount of 120GB. We'll assume a daily change 
> rate on abount 10GB on each volume
> , totalling to a 30GB/24hrs. Would this be quicker than a 30GB change on 
> a 120GB volume?

> both setups: two servers -> one master and a replica.

> And if it's faster - why?

It may not be faster, but if an operation fails and has to restart, it
will lose only the update attempt for one volume, or up to 10GB to
retransmit, not 30GB.  And it will take a while to transmit 10GB, so a
failure is likely.  I don't know what today's transfer rates are, but
it's likely in the few-MB per second.  Even saying 10MB/second (perfect
utilization of a 100Mbps link), that's a thousand seconds to transmit
10GB, or around 20 minutes.

By the way, you might want to reconsider the second level of your tree
under /afs; it's conventional to put a cell name there so that you might
someday be able to deal with multiple cells.

Excerpts from mail: 10-Dec-01 Re: Large volumes David M. Karlsen at davidka
(1866*)

> that's why I want to go for one big volume: /afs/data

It's far less failure-prone to have many smaller volumes.  Remember that
you'll replicate the mount points as you replicate the parent volumes,
so that you *will* have multiple copies of the same stuff.

		Craig