i have four cf card and i have one pci based cf card contoller(addonics card with pata_sil6800 driver).when i am connecting this four cf card to addonics card(which has four slots for cf cards) and inserting this total hardware package to pci slot of pc in linux os it is showing four different block devices to me.So using mdadm 2.6.3 software raid i am creating a raid device of level 0 . If one cf card from this hardware package getting failed the raid-device is becoming inactive .If i am trying to reactive the raid device using mdamd -R command it is giving a error of "memory cannot be allocated for the raid device " .The same thing i am trying with raid10 (our hardware only supports raid level 0 ,1,10) and if one cf card got failed we are abel to reactive the raid device.But the issue we are facing in raid10 is it is taking 50%(2-CF card out of 4) of total memory space as mirroring which is a loss for us . So we dont want any kind of data recovery in our raid device (like raid0) but we want if one cf card failed also, the raid device should run or should reactive without any error(like raid10) but we should abel to use the total disk space (like raid0). or any idea to increase size of storage memory created by raid10 (50% is going waste due to mirroring and our hardware doesnot support raid5) . How we are simulating a cf card fail? answer: according to raid document " http://tldp.org/HOWTO/Software-RAID-HOWTO-6.html " if we switch of the system and remove a cf card ,it will simulate a disk failure . Please provid any help to me i will be kind of you. thanking you for your genuine support ANSH -- 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