Thank you. Sent from my iPhone
> On May 22, 2021, at 12:39 PM, Radoslaw Skorupka <[email protected]> > wrote: > > Two things to consider: > 1. Distance => delay. For long distances it means synchronous copy is not > applicable. It can be asynchronous copy or some kind of "fuzzy" copy like > PPRC-XD or SRDF Adaptive Copy. > > 2. Bandwidth and I/O rate. The more I/O the higher bandwidth is needed for > replication. Temporary spikes are managed by "delta", but it doesn't mean you > can do a lot of I/O during business hours and rebalance delta on evening. It > is complex topic, especially when fuzzy copy is considered. > > BTW: Before you start you can establish some POC configuration. There are > devices simulating distance (delay) and bandwidth limitation. So, you can > have 9000 miles in single computer room. > Note: it is not 9000 miles of fiber optic in a suitcase - such devices are > actually used for much shorter distances (10-20km) and rather for synchronous > copy. > > > -- > Radoslaw Skorupka > (looking for new job) > Lodz, Poland > > > > > > > W dniu 21.05.2021 o 21:34, Cameron Conacher pisze: >> Hello folks, >> I am trying to find out what we could consider to be a "safe" maximum >> distance for mirroring DASD from one site to another. >> We have a situation where site #1 will be thousands (9,000) of miles away >> from site #2 (across the ocean. >> >> I realize there would be a great deal of latency involved. >> But is this even possible or is it simply a non-starter? >> >> The second question I have is, suppose that I waved a magic wand and >> suddenly all my data was sitting comfortably in site #2. >> Could I (again ignoring latency for the moment) run a batch JOB or CICS >> transactions in site #1 that accessed the data 9,000 miles away in site #2? >> My thought here was if the data must absolutely be relocated, and >> people are willing to accept there will be latency, can we just access the >> DASD at site #2, rather than building a large data centre and performing >> all of the processing in site #2? >> Even if we run the processing at site #2, there will be many interfaces >> between site #1 and site #2. >> >> I know there are hard distance limitations. >> I think Global Mirror is limited to about 1500 miles. >> And I would hazard a guess that remote DASD would not be viable either. >> >> But I wanted to see if someone really "knows", rather than something I may >> have mis-remembered. >> >> Any thoughts/opinions are appreciated. >> >> Thanks >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
