Mark, On Saturday 08 October 2005 18:16, you wrote: > > In an ideal world both source and destination drive share the same > > geometry. The partition table could easily be copied using sfdisk. > > or dd. but really, with LBA, most drives already use the same geometry; > have you looked? 255 heads, 64 sectors/track, but a variable number of > cylinders. > > which makes sense, since "rectangular" geometries have been lies for a long > time (all drives have variable spt.) I tried copying the partition table using sfdisk and it complained about "partition does not start at a cylinder boundary". After re-running with the --force flag (like a dd copy would do) and formatting the partition, the system went nuts. Thanks for the hint of variable number of cylinders, but I rather not rely on that as I want to solve this in a generic manner. > > What's this all for you might ask? > > If one disc in a RAID1 array (without a preconfigured hot spare) fails, > > I want to plug in a replacement disc and the rest should be handled > > by some automatic system (partition the drive, hot-add it afterwards). > > this level of automaticity is normally considered bad because it > has extremely unpleasant failure modes. (consider what happens if > your sysadmin-assistant, low on coffee one monday morning, > plugs in a drive which he *doesn't* want to be auto-sucked into the > array...) ;-) > does the devfs/hotplug mechanism let you trigger a script when a new > drive appears? this would depend somewhat on the fabric - I suspect that > scsi still needs an explicit rescan command. I don't want it that automatic. You still have to push a button / run a script to activate the new drive. Ideally from a little web frontend which shows the current status of the array, too. Thomas - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
