Ed Heron wrote: > From: "Phil Schaffner", Tuesday, April 28, 2009 5:36 PM > >> I have attempted to address all comments: >> >> http://wiki.centos.org/HowTos/SoftwareRAIDonCentOS5 >> >> Give me your best shot! :-D >> >> Phil > > There's always going to be an argument about whether to put /boot and swap > on RAID. It's all about performance most of the time being slightly better > versus stability in the event of device failure. I can't think of a good argument for not having /boot on the raid1. Presumably performance isn't an issue as the contents of /boot gets read once at system boot (other than maybe fast booting performance, but that's not really going to be an issue for a server running raid1, right?) SWAP on raid0 is a bad idea as one drive failure may cause the system to fail to boot. I guess SWAP on raid1 is the safe option. If SWAP performance is critical, then maybe two independent non-raid partitions, one at the start of each drive, and set to the same priority would be a better solution (effectively giving stripped raid0 performance). Presumably then a drive failure wouldn't prevent booting but would result in a warning that one of the SWAPs was unavailable (assuming the system could function fine with the size of the remaining SWAP)? Hopefully someone can verify my logic here. > > What's the disaster recovery plan here? > > Obviously, if the second drive fails, there's no issue. Standard removal > and eventual addition of replacement device(s). > > If the first drive fails, are we hoping the computer will boot off the > second drive or are we moving the second drive to the first interface? > If grub is present on the mbr of both drives, then the system will remain functional if *either* drive fails without any further intervention. I would think this is the ideal. > Is it outside the scope of this document to describe and test disaster > recovery? I think it is. I'm just making a note to suggest a further > complimentary page at some time in the future... (though, at this time, I > am NOT volunteering to write it) Is there a wiki page todo list somewhere? > I would be in favour of extending the current page to include testing/recovery information in the event of a drive failure. If the information is not specific to only raid1, then maybe a separate page is warranted.
