On 07/03/2013 11:50 AM, Vasiliy Tolstov wrote: > 2013/7/3 Gabriel de Perthuis <g2p.code@xxxxxxxxx>: >> Hello, >> >> You could use `blocks to-lvm`[1] to convert your large disk to lvm, >> and then `blocks to-bcache` to convert the lvm volume to bcache. >> The lvm conversion will allow you to migrate the data off the >> prefailed disk later, either by moving it (pvmove) or by converting >> to raid1 (lvconvert). > > Why i can't do : > > create /dev/md0 with /dev/sda (sata) level=1 raid-devices=1 > format /dev/md0 with bcache > format /dev/sdb (ssd) with brache > > create bcache0 with /dev/md0 and /dev/sdb > > ? If you want md0 to be a raid1 device in the future you need to create it as a 2 device array with a missing drive: mdadm -C /dev/md0 -l1 -n2 /dev/sda missing You can then add in the other device whenever you can/want. The key though would be to make sure the size in blocks of the first device is = or smaller than the second device will be. What I would do is create a fd type partition that is 1% smaller than total raw device size on /dev/sda just to give your self a small margin of error. parted /dev/sda mkpart primary 1.0 99% --align optimal parted /dev/sda set 1 raid on mdadm -C /dev/md0 -l1 -n2 /dev/sda1 missing That way down the road you can add in a disk of about the same size to the existing raid1 completely transparent of bcache with a single command. mdadm /dev/md1 -a /dev/sdX1 > > > -- > Vasiliy Tolstov, > e-mail: v.tolstov@xxxxxxxxx > jabber: vase@xxxxxxxxx > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" 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-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
