Hello Neil, Thanks for the confirmations! It's all very clear now. Case closed. Best, Seb. On Sat, 21 Jul 2007, Neil Brown wrote: | On Saturday July 21, seb@xxxxxx wrote: | > | > Hi Neil, | > | > | > | > Could you tell me if such a mechanism exists in mdadm? | > | > Or should I accept the "loss" of the 150 GB? | > | When you give mdadm a collection of drives to turn into a RAID array, | > | use bases the size of the array on the smallest device. | > | > I'm sorry I don't know what "bases" are in a RAID array and I can't find | > this term in the man page. Could you elaborate? | | Typo. Should be | It bases the size of the array ... | | i.e. it works out which is the smaller device, and uses that size to | determine the size of the array. e.g. if you are making a raid5 with | 4 drives, then the array will be 3 times the size of the smallest array. | | > | > | You might want to make it a little smaller still in case you have to | > | replace a device with a slightly smaller device (it happens). You can | > | use "--size" to reduce the used space a little further if you like. | > | > Thanks for the pointer to --size! I had overlooked this option. The man | > page says that "If this is not specified (as it normally is not) the | > smallest drive (or partition) sets the size". This implies that partitions | > need not have exactly the same size and 'mdadm' will still manage. | | Exactly. | | > | > So I'll use 249,9GB out of 250GB, skip over the small resulting | > differences, let mdadm work its magic and when new disks will be inserted | > after a failure it will suffice to use their total space. | | Again, exactly correct. | | NeilBrown | - 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
