* Matthew Seaman <[EMAIL PROTECTED]> [060715 02:30]: > Javier Henderson wrote: > > * Mike Jakubik <[EMAIL PROTECTED]> [060714 17:15]: > > >> The chipset is supported, but i wouldn't recommend onboard raid for any > >> production server. Get a real raid controller, or use gmirror if you > >> plan to mirror. I use several of these board sin production with gmirror. > > > Why do you recommend against on-board RAID controllers? > > Think about what happens if one of your disks dies. Sure, the machine will > carry on running. With an on-board controller there are two problems: > > i) How do you get notified that a disk has died > ii) How do you replace the drive > > (i) you'ld likely only find out about at reboot time, or by noticing a > change in the pattern of blinken-lights on the machine. (Don't laugh -- > it happens)
Good point. The Intel motherboard I have with on-board RAID controller doesn't have a notification features as I've seen on stand-alone controllers. > (ii) is not just about having to power off the machine and swap out the > hardware: it's not uncommon for on-board RAID-1 setups to be unable to > rebuild a mirror by duplicating the good disk onto the replacement one. That > means blowing everything away and recovering from backup. By which time > you've had so much downtime that you might as well not have bothered with > RAID in the first place. Well, in my case, I mentioned I have the Intel D945PVS motherboard. Before storing valuable data, I did take out a drive (out of four in a RAID 5 configuration) while reading and writing to/from the array, and it just kept on going. Then I put the disk back, and things got slow while parity was rebuilt, but in the end the array was back to healthy status. > The advantage of a good RAID controller -- like one of the 3ware cards > -- or of gmirror is that combined with hot-swap disk (and pretty much all > SATA drives nowadays have hot-swap capability; you just need to find a > chassis with the right sort of drive bays) then you can take out the dead > disk, replace it with a good one and rebuild the array *without taking the > machine down*. > > gmirror will alert you to failures in the nightly e-mail if you enable > the 406.status-gmirror periodic script. Similarly a good hardware RAID > controller will have a system level control application to let you interface > with the card from the OS level, and it will have some mechanism for alerting > the admin to problems. Yes, there are indeed good advantages to stand-alone controllers, and in some cases they justify the expense. Thanks for taking the time to post a reply. -jav _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
