Hi, I am going through understanding the fundamentals of raidz. From the man pages, a raidz configuration of P disks and N parity provides (P-N)*X storage space where X is the size of the disk. For example, if I have 3 disks of 10G each and I configure it with raidz1, I will have 20G of usable storage. In addition, I continue to work even if 1 disk fails.
First, I don't understand why parity takes so much space. From what I know about parity, there is typically one parity bit per byte. Therefore, the parity should be taking 1/8 of storage, not 1/3 of storage. What am I missing? Second, if one disk fails, how is my lost data reconstructed? There is no duplicate data as this is not a mirrored configuration. Somehow, there should be enough information in the parity disk to reconstruct the lost data. How is this possible? Thank you in advance for your help. Regards, Peter -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
