> But is seems that when we're talking about full block
> writes (such as
> sequential file writes) ZFS could do a bit better.
>
> And as long as there is bandwidth left to the disk
> and the controllers, it
> is difficult to argue that the work is redundant. If
> it's free in that
> sense, it
>consolidating these writes in host cache eliminates some redundant disk
>writing, resulting in more productive bandwidth ... providing some ability to
>tune the consolidation time window and/or the accumulated cache size may
>seem like a reasonable thing to do, but I think that it's typically a
> I have a question that is related to this topic: Why
> is there only a (tunable) 5 second threshold and not
> also an additional threshold for the buffer size
> (e.g. 50MB)?
>
> Sometimes I see my system writing huge amounts of
> data to a zfs, but the disks staying idle for 5
> seconds, althoug
>
> the ZIL is always there in host memory, even when no
> synchronous writes
> are being done, since the POSIX fsync() call could be
> made on an open
> write channel at any time, requiring all to-date
> writes on that channel
> to be committed to persistent store before it returns
> to the appl
file system journals may support a variety of availability models, ranging from
simple support for fast recovery (return to consistency) with possible data
loss, to those that attempt to support synchronous write semantics with no data
loss on failure, along with fast recovery
the simpler models
parvez shaikh wrote:
> Hello,
>
> I am learning ZFS, its design and layout.
>
> I would like to understand how Intent logs are different from journal?
>
> Journal too are logs of updates to ensure consistency of file system
> over crashes. Purpose of intent log also appear to be same. I hope
Hello,
I am learning ZFS, its design and layout.
I would like to understand how Intent logs are different from journal?
Journal too are logs of updates to ensure consistency of file system over
crashes. Purpose of intent log also appear to be same. I hope I am not missing
something important
