} -----Original Message----- } From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- } owner@xxxxxxxxxxxxxxx] On Behalf Of Janek Kozicki } Sent: Monday, October 08, 2007 6:47 PM } To: linux-raid@xxxxxxxxxxxxxxx } Subject: Re: very degraded RAID5, or increasing capacity by adding discs } } Janek Kozicki said: (by the date of Tue, 9 Oct 2007 00:25:50 +0200) } } > Richard Scobie said: (by the date of Tue, 09 Oct 2007 08:26:35 } +1300) } > } > > No, but you can make a degraded 3 drive array, containing 2 drives and } > > then add the next drive to complete it. } > > } > > The array can then be grown (man mdadm, GROW section), to add the } fourth. } > } > Oh, good. Thanks, I must've been blind that I missed this. } > This completely solves my problem. } } Uh, actually not :) } } My 1st 500 GB drive is full now. When I buy a 2nd one I want to } create a 3-disc degraded array using just 2 discs, one of which } contains unbackupable data. } } steps: } 1. create degraded two-disc RAID5 on 1 new disc } 2. copy data from old disc to new one } 3. rebuild the array with old and new discs (now I have 500 GB on 2 discs) 3. Add old disk to new array. Once done RAID5 is redundant. } 4. GROW this array to a degraded 3 discs RAID5 (so I have 1000 GB on 2 } discs) 4. Buy 3rd disk. 5. Add new 3rd disk to array and grow to 3 disk RAID5 array. Once done, array is redundant. Repeat 4 and 5 each time you buy a new disk. I don't think you can grow to a degraded array. I think you must add a new disk first. But I am not sure. } ... } 5. when I buy 3rd drive I either grow the array, or just rebuild and } wait with growing until I buy a 4th drive. } } Problems at step 4.: 'man mdadm' doesn't tell if it's possible to } grow an array to a degraded array (non existant disc). Is it possible? } } } PS: the fact, that degraded array will be unsafe for the data is an } intented motivating factor for buying next drive ;) } } -- } Janek Kozicki | } - } 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 - 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
