Volume manager or zfs

Question

I have veritas volume manager in a couple of systems.
Zfs is it similar ?
I read the documentation, and, the pool disk creation, file systems depend of the pool of disk. Its like veritas.
What is the big difference ?

Answer 1

Refer to the first link which I provided. What I
meant is that those admins who use fsck on occasion
will realise that the zfs filesystems do not have
such a utility or requires one (as yet).Correct. It's not needed.
Yes it does resilver data - provided you are using
redundant disks - the zfs data integrity model is
based on checksumming - the checksums assists zfs to
recognise data is bad, but in order ot this to
resilver data - it must check the other copy - zfs
will allow you to create unmirrored filesystems -
this means - that if you did not use the replication
features using mirroring or raidz - you are SOL. Of course. This is no different from any other volume manager. I was just confused by your original quote that it would "resilver corrupted data
by means of the built-in checksumming." It may use checksumming for verification, but it must resilver from redundant storage, not the checksum. If no redundant storage exists, then your data is gone, just like any other storage system.
I'm not nervous about the lack of fsck - If I have to
use this filesystem on my company's data - and
something terrible happens - the questions management
will ask: Why did you use zfs? Were you aware of
potential issues? Has this been tested in a
development environment?
I'm not working in a fictious environment but one
that contains terabytes of data. It is my
responsibility to find tested and proven
technologies, leverage them in order to achieve a
stable environment. New technologies are always
tested as proof of concept then tested further in
development. A business case is then written which
justifies the use of that technology. I'm not
nervous.Yes, as expected. Even besides design issues, the age of ZFS is still young compared to other similar technology. There are still known bugs and limitations with ZFS. Those would be my primary concern before using it in production.
I just didn't know what you were referring to with the "if you're willing to overlook this" sentence. I was assuming that something about the lack of fsck was a problem that had to be overlooked. That's why I was asking for clarification.
There's no fsck by design, and resilvering data works similarly to other volume managers (except that it does so only after verification, not blindly). So I'm not sure what I'm supposed to overlook.
Darren