> On Tuesday, August 1, 2023 at 07:59:07 AM PDT, Grant Taylor wrote: >> On 8/1/23 2:49 AM, Colin Paice wrote: >> You can have synchronous write - used in same "site" and async -
>> where the remote end is miles away. This is used for media failure. > Yes. Emphasis on /media/ failure. This does nothing for /data/ > failure, e.g. corruption / malicious activity. > Traditional offline backups address both /media/ failure and /data/ failure. > Note. This is not a backup. If you delete the dataset, both copies will be > deleted. > I usually see snapshots created a couple of different ways: > 1) The older way was to pause things and take an actual copy. Tunnel vision is the biggest problem people need to address. IBM GDPS is decades old and has always included an IBM services contract to specifically address customer tunnel vision. They start with a big picture approach by first identifying the recovery requirements and recovery problems that must be addressed. Only at that point can you then decide the software, hardware and procedural components to best meet the requirements and solve the problems. To say "This is not a backup" ignores the stated requirements (delete a file and have a backup). Rename resolves both requirements. To say "async - where the remote end is miles away" denies the existence of GDPS. As in the name implies, Globally Dispersed Parallel Sysplex, you can have a sysplex split between 2 active locations. Sync is a sysplex requirement. To say "usually see snapshots" ignores requirements. A GDPS customer will have many requirements and money is usually lowest on the list (or not on the list). Consider for instance, a dual copy disk on both sites of the sysplex and each disk is mirrored (2 disks on at each site). When all commits have completed, turn off mirroring at one site and you have a moment in time backup, site failure recovery if the unmirrored disk fails and site failure recovery if the mirrored disk site fails. Recovery is far more complicated than a single component. There is substance to everything being said but realize this is a truth, but not necessarily the complete truth. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
