On Thu, Oct 15, 2015 at 08:24:51AM -0400, Austin S Hemmelgarn wrote:
My only point with saying we shouldn't reflink by default is that there are
many (unintelligent) people who will assume that since the syscall has copy
in it's name, that's what it will do; and, while I don't think we should
cater to such individuals, it does make sense to have a syscall that says in
it's name that it copies data actually do so by default.
As far as the user is concerned a reflink is a copy. A very efficient
copy.
On 2015-10-16 01:38, Christoph Hellwig wrote:
On Thu, Oct 15, 2015 at 08:24:51AM -0400, Austin S Hemmelgarn wrote:
quoted
My only point with saying we shouldn't reflink by default is that there are
many (unintelligent) people who will assume that since the syscall has copy
in it's name, that's what it will do; and, while I don't think we should
cater to such individuals, it does make sense to have a syscall that says in
it's name that it copies data actually do so by default.
As far as the user is concerned a reflink is a copy. A very efficient
copy.
I should have been specific, what I meant was that some people will
assume that it actually creates a physical, on-disk byte-for-byte copy
of the data. There are many people out there (and sadly I have to deal
with some at work) who are absolutely terrified of the concept of data
deduplication, and will likely refuse to use this syscall for _anything_
if it reflinks by default on filesystems that support it.
On 16/10/15 12:46, Austin S Hemmelgarn wrote:
On 2015-10-16 01:38, Christoph Hellwig wrote:
quoted
On Thu, Oct 15, 2015 at 08:24:51AM -0400, Austin S Hemmelgarn wrote:
quoted
My only point with saying we shouldn't reflink by default is that there are
many (unintelligent) people who will assume that since the syscall has copy
in it's name, that's what it will do; and, while I don't think we should
cater to such individuals, it does make sense to have a syscall that says in
it's name that it copies data actually do so by default.
As far as the user is concerned a reflink is a copy. A very efficient
copy.
I should have been specific, what I meant was that some people will
assume that it actually creates a physical, on-disk byte-for-byte copy
of the data. There are many people out there (and sadly I have to deal
with some at work) who are absolutely terrified of the concept of data
deduplication, and will likely refuse to use this syscall for _anything_
if it reflinks by default on filesystems that support it.
Right. reflinking is transparent to the user, though its consequences are not.
Consequences being the possible extra latency or ENOSPC on CoW.
Therefore reflinking should be an explicit action/flag IMHO.
cheers,
Pádraig.
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