ALERT.. Long Winded reply ahead.. cindy.swearin...@sun.com writes:
> Harry, > > Bob F. has give you some excellent advice about using mirrored > configurations. I can answer your RAIDZ questions but your original > configuration was for a root pool and non-root pool using 4 disks > total. I didn't make it clear. 1 disk, the one with rpool on it is 60gb. The other 3 are 500GB. Using a 500gb to mirror a 60gb would be something of a waste .. eh? And is a mirror of rpool really important? I assumed there would be some way to backup rpool in a format that could be written onto a new disk and booted in the event of rpool disk failure. With the backup not kept on rpool disk. Someone had suggested even creating an rpool mirror and putting the bootmanager bits on its mbr but then keeping it in storage instead of on the machine (freeing a controller port). It has the downside of having to be re mirrored every now and then. But could be safe enough if nothing of great importance was kept on the rpool... Just OS and config changes, some BE's. But nothing that couldn't be lost. Then in the event of disk failure... You'd have to just install the spare, boot it, and bring it up to date. Something kind of like what people do with ghost images on windows OS. > Start with two mirrored pools of two disks each. In the future, > you will be able to add two or more disks to your non-root pool. > You can't do that with a RAIDZ pool. Well one thing there... if I use 5 500gb disks (no counting rpool disk - 6 total), by the time my raidz fills up, I'll need a whole new machine really since I'll be out of controller ports and its getting hard to find controllers that are not PCI express already. (My hardware is plain PCI only and even then the onboard sata is not recognized and I'm addding a PCI sata controller already) Also some of the older data will have outlived its usefulness so what needs transferring to a new setup may not be really hard to accommodate or insurmountable. And finally, I'm 65 yrs old... Its kind of hard to imagine my wife and I filling up the nearly 2tb of spc the above mentioned raidz1 would afford before we go before the old grim reaper. Even with lots of pictures and video projects thrown in. I'm really thinking now to go to 5 500gb disks in raidz1, and one hotswap (Plus the rpool on 1 60gb disk). I would be clear out of both sata and IDE controller ports then, so I'm hoping I can add a hot swap by pulling one of the raidz disks long enough to add the hotswap... then take it back out and replace the missing raidz disk. I could do this by getting 3 more 500gb disks 2 more for the raidz and 1 for hotswap. No other hardware would be needed. All the while assuming I can mix 3 500GB IDE and 2 500GB SATA with no problems. > If you need to, you can even detach one side of the mirror > of each pool. You can't do that with a RAIDZ pool. If you need > larger pools you can replace all the disks in both pools with > larger disks. You can do that with a RAIDZ pool, but more > flexibility exists with mirrored pools. > > 1. Yes, sensible. > 2. Saving space isn't always the best configuration. > 3. I don't know. > 4. Yes, with more disks, you can identify hot spares to > be used in the case of a disk failure. Nice thanks (To Bob F as well). And I'm not being hard headed about using a mirror config. Its just that I have limited controller ports (4 ide 2 sata), limited budget, and kind of wanted to get this backup machine setup to where I could basically just leave it alone and let the backups run. On 3) Mixing IDE and SATA on same zpool I'd really like to hear from someone who has done that. About 4).. so if all controllers are already full with either a zpool or rpool. Do you pull out one of the raidz1 disks to add a hotswap then remove the hotswap and put the pulled disk from the raidz back? If so, does that cause some kind of resilvering or does some other thing happen when a machine is booted with a raidz1 disk misssing, and then rebooted with it back in place? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
