1) Is a hardware-based RAID behind the scenes needed? Can ZFS safely be considered a replacement for that? I assume that anything below the filesystem level in regards to redundancy could be an added bonus, but is it necessary at all?
2) I am looking into building a 10-drive system using 750GB or 1TB SATA drives (when they come out) - I assume that I would need to plan for normal RAID-5 type storage usage with NUMDISKS-1 as the total amount of storage. Do I manage that at all, or is it completely managed by ZFS? If so, does ZFS calculate the free disk space after it takes in to account the space needed to store the parity data? 3) I see RAID-Z is the equivalent of RAID-5, and RAID-Z2 is RAID-6 (dual parity) - can these be interchanged (i.e. if a decision is made to switch to double the parity, can it be moved back to single parity? and vice-versa? assuming there is enough free space available for the second parity) 4) What happens if multiple disks fail? I am looking between RAID-Z and RAID-Z2. I understand one or two could die in Z or Z2, what happens if half the array disappears (one of the enclosures power supplies fails, perhaps) - is there some method to "halt" until it is manually fixed then? 5) Follow up question: can a new, larger disk be put in it's place? What about smaller? Will ZFS understand that? 6) Assumption: disks can be permanently removed (as long as there is enough leftover space) 7) Will upgrades to the filesystem work easily? When encryption is supported I would be interested in upgrading to that version to take advantage of that. Sorry for the amount of questions, it will help me gain more understanding of this. I'm trying to consume as much information about ZFS as possible, and it helps to get the official answers back with questions phrased in a format I understand. Thanks in advance! P.S. Just for information's sake, I plan on setting up one or multiple sets of 5 or 10 drive eSATA-based arrays - for instance the 10 bay, 2 port eSATA one here: http://fwdepot.com/thestore/product_info.php/products_id/1578 alongside some Solaris x86/OpenSolaris-compliant eSATA adapter [if anyone has any suggestions, feel free to reply directly to me!]) - this would be used for home media storage + offsite redundant backup for multiple locations for my webhosting business. Not heavy traffic, perhaps 3-5 people accessing it at once. Files probably on average more than a few megs - so wouldn't be *too* sparse... _______________________________________________ zfs-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
