Hi M > 1.: Use drdb to build a RAID1 across the two host's filesystems. If one > host fails, the RAID runs in degraded mode but it runs - or does it > crawl anyway because drdb is slow? [Mitch says:] I've never used this, and a quick google doesn't give me anything useful - what's the home page?
> 2.: Use rsync. If I remember correctly, rsync was not supposed to run > permanently as a daemon to keep two filesystems in sync(?). I could live > with that, but how big is the overhead if I ran rsync every 5 or 10 > minutes? [Mitch says:] This is something I've been playing with. Wasn't having any problems until the filesets got largish (>40GB) - now I see performance issues.... one key is to write your sync script with a lock - you don't want cron starting a second one while the first is still running - at some point, I'd like to investigate some performance enhancements to rsync - either to pull a file list from fam or something to eliminate deep traversal of unmodified dirs (may involve a file system hack). > I want to achieve a trouble free passive fallover. I one host fails, > people might have to login again and they even might have to wait up to > 30 minutes but then it has to work and they have to get all their files. > > This is a public school and data is not worth real money most of the > time, but once in year there are final exams written and if the server > breaks down the whole exam has to be redesigned - that could bring me > into the news. > [Mitch says:] Personally (SCSI bigots aside ;-) I don't have any issues with SATA drives for a low demand server - sure ultra fast scsi would be quicker, but a large mirror ALWAYS beats smaller drives in raid 5 or other more controller dependant setups. There are even a few controllers that do the raid as a "hardware" sata raid - Adaptec has one - 3ware too I think. They have proper recovery tools and so on for FreeBSD and Linuxes I think. m/ -- To unsubscribe from this list go to the following URL and read the instructions: https://lists.samba.org/mailman/listinfo/samba
