I'm going to post this to the whole list, because it is so dramatic. The only question that matters here is, "Is it an email inbox? yes or no." If the answer is Yes, the daily change rate approaches 100%.
Roger Deschner University of Illinois at Chicago [EMAIL PROTECTED] On Fri, 4 Jun 2004, Steve Harris wrote: >Hi All, > >I'm trying to size TSM servers for some small remote sites that we have. In the >past, with more primitive products, one of the issues has been getting staff in these >locations - generally nurses - to physically change tapes. For that reason, and to >avoid the cost of a library, I'm looking at a disk primary pool and tape copypool, >with db back ups up the wire to a "mother" site. > >I've written a program that models the TSM backup and expiry process. Some >assumptions are a small daily update rate, but a file changed yesterday is 50% >likely to be changed today and 25% if it was changed in the last week. I realize in >the real world that there are weekly and monthly cycles too, but I've left them out >for the model for simplicity. > >With a 1% daily change rate, 35 day retention and no compression, I'll need 5.7 times >the original data space (thats steady state average +3 standard deviations), but the >number is quite sensitive to the daily rate of change > >1% 5.7 >1.25% 6.5 >1.5% 7.1 >1.75% 7.9 >2% 8.6 >2.5% 9.8 >3% 10.7 >5% 13.2 >10% 16.9 > >At the moment, I don't back up any File servers, so I have no idea what a usual rate >of change might be. > >First, can anyone comment on my assumptions. > >Second, can anyone share change rates for file servers with a normal load of office >workers creating word processing docs, spreadsheets, etc. I understand that Netware >changes attributes in situations where Windows does not, so if you could say which >type of OS you are using that would be handy too. > >Rather than flood the list, email direct to me at [EMAIL PROTECTED] and I'll >summarize. > > >Thanks > >Steve Harris >AIX and TSM Admin >Queensland Health, >Brisbane Australia > > > > >*********************************************************************************** >This email, including any attachments sent with it, is confidential and for the sole >use of the intended recipient(s). This confidentiality is not waived or lost, if you >receive it and you are not the intended recipient(s), or if it is >transmitted/received in error. > >Any unauthorised use, alteration, disclosure, distribution or review of this email is >prohibited. It may be subject to a statutory duty of confidentiality if it relates >to health service matters. > >If you are not the intended recipient(s), or if you have received this email in >error, you are asked to immediately notify the sender by telephone or by return >email. You should also delete this email and destroy any hard copies produced. >*********************************************************************************** >
