From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valdis.Kletnieks@vt.edu (Valdis.Kletnieks at vt.edu) Date: Mon, 18 Apr 2016 10:43:00 -0400 Subject: anyone aware of a high availability setup that relies on fully redundant install? In-Reply-To: References: <208224.1460954905@turing-police.cc.vt.edu> Message-ID: <255315.1460990580@turing-police.cc.vt.edu> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Mon, 18 Apr 2016 06:29:21 -0400, "Robert P. J. Day" said: > that makes sense -- a *minimal* bootable system for recovery and > troubleshooting. but not a fully independent previous install. No, it's a *complete* system - your kernel boot image, /, /usr, /var, and whatever other file systems you specified to go into 'rootvg'. The use case is that before doing maintenance or whatever, you run a shell script that clones the entire rootvg over to alt_rootvg. Or you can apply system updates to the alternate boot, so instead of taking an outage for 2 hours to apply all your fixes, you apply fixes onto the alternate, and your outage window is only what it takes to reboot to the updated image - and you still have the old image to fall back to. Incredibly useful for that set of systems that you need to minimize downtime, but the application in question isn't one that you can run multiple instances behind a load balancer. We've used it for everything from a Listserv server to a TSM backup server. http://sureshaix.blogspot.com/2008/07/alternate-disk-installation.html http://www.drdobbs.com/aix-alternate-disk-installation/199101222 (Yes, that's an article from 1991.. :) -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 848 bytes Desc: not available Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20160418/450643d4/attachment.bin