[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-13 Thread Anton B. Rang
Is this true for single-sector, vs. single-ZFS-block, errors? (Yes, it's pathological and probably nobody really cares.) I didn't see anything in the code which falls back on single-sector reads. (It's slightly annoying that the interface to the block device drivers loses the SCSI error

[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Ceri Davies
Hi Matt, Interesting proposal. Has there been any consideration if free space being reported for a ZFS filesystem would take into account the copies setting? Example: zfs create mypool/nonredundant_data zfs create mypool/redundant_data df -h /mypool/nonredundant_data

[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Anton B. Rang
The biggest problem I see with this is one of observability, if not all of the data is encrypted yet what should the encryption property say ? If it says encryption is on then the admin might think the data is safe, but if it says it is off that isn't the truth either because some of it maybe

Re: [zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Darren J Moffat
Anton B. Rang wrote: The biggest problem I see with this is one of observability, if not all of the data is encrypted yet what should the encryption property say ? If it says encryption is on then the admin might think the data is safe, but if it says it is off that isn't the truth either

[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Anton B. Rang
True - I'm a laptop user myself. But as I said, I'd assume the whole disk would fail (it does in my experience). That's usually the case, but single-block failures can occur as well. They're rare (check the uncorrectable bit error rate specifications) but if they happen to hit a critical file,

[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Celso
Take this for what it is: the opinion on someone who knows less about zfs than probably anyone else on this thread ,but... I would like to add my support for this proposal. As I understand it, the reason for using ditto blocks on metadata, is that maintaining their integrity is vital for the

Re: [zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Dick Davies
On 12/09/06, Celso [EMAIL PROTECTED] wrote: One of the great things about zfs, is that it protects not just against mechanical failure, but against silent data corruption. Having this available to laptop owners seems to me to be important to making zfs even more attractive. I'm not arguing

[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-12 Thread Celso
Matthew Ahrens wrote: Here is a proposal for a new 'copies' property which would allow different levels of replication for different filesystems. Thanks everyone for your input. The problem that this feature attempts to address is when you have some data that is more important

[zfs-discuss] Re: Proposal: multiple copies of user data

2006-09-11 Thread William D. Hathaway
Hi Matt, Interesting proposal. Has there been any consideration if free space being reported for a ZFS filesystem would take into account the copies setting? Example: zfs create mypool/nonredundant_data zfs create mypool/redundant_data df -h /mypool/nonredundant_data