William Warren spake the following on 4/2/2007 5:16 PM: > of course if you need a card to do this then you don't need MD > raid(unless the card is a FRAID card) > > Scott Silva wrote: >> Les Mikesell spake the following on 4/1/2007 11:37 AM: >>> Jeff Lasman wrote: >>> >>>>> if the hardware can hotswap then you should be ok if i am reading >>>>> what les said correctly. >>>> From time to time (not now) I have a machine on my testbed I can test >>>> this on. >>>> >>>> Should I break the software RAID first? I'd think so. >>> No, you'd expect a failure to automatically kick the drive out of the >>> raid and go on about its business. >>> >>>> Do I have to remake the RAID automatically? I'd think so. >>> Yes, you have to 'mdadm --add ...' to make the replacement sync back up. >>> >>>> Can I physically damage either drive? >>>> >>>> I'd think not. >>>> >>>> So I'm not sure I understand the problem as long as the (sata) drive >>>> is in a hotswap bay. >>>> >>>> Anything I'm missing? >>> The question is whether the kernel will notice the new drive when you >>> add it. It might be possible to swap in an exact match and get away >>> with the setup detected at boot time but that doesn't sound very >>> healthy. Can you hotswap a new SATA drive that wasn't present at boot >>> time and have the kernel notice the new drive device and its partitions. >>> If the partitions are recognized, mdadm will be able to add them. >>> >> I think you would need a hot-swap capable controller also in addition >> to the >> hot swap drive cage. Some controllers can be made to re-scan the bus, >> some >> can't. But a card that is designed to support hot swap will have this >> feature. >> >> > I think that is the whole point. Hotswap may work with some devices on mdraid, but if you have the hardware that will hotswap, you probably have a real raid card and won't need mdraid anyway. And if you have a system that is so critical that you can't reboot to change a failed drive, you shouldn't be using mdraid. -- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!!