On 7/1/07, Wayne Davison [EMAIL PROTECTED] wrote:
[...] It is still useful for allowing a server to cache the
checksum values without requiring any extra files. As long as it is
used on files that aren't being actively updated, it works great.
OK, that's reasonable.
Second, it is
On Mon, Jul 02, 2007 at 08:43:39AM -0400, Matt McCutchen wrote:
What do you mean? There's no way to fix the example I gave with
xattrs
Not so. I went on to explain how that is possible in my prior email
(i.e. avoiding caching a checksum on a now mtime file is all that is
needed).
That's
On Mon, Jul 02, 2007 at 10:28:25AM -0700, Wayne Davison wrote:
It is if you're doing one check to see if a file is being updated (e.g.
stat() followed by time() to compute now). If time rolls over between
the two calls, you may have just missed that the mtime would now match
if you did
On 7/2/07, Wayne Davison [EMAIL PROTECTED] wrote:
On Mon, Jul 02, 2007 at 08:43:39AM -0400, Matt McCutchen wrote:
What do you mean? There's no way to fix the example I gave with
xattrs
Not so. I went on to explain how that is possible in my prior email
(i.e. avoiding caching a checksum on a
On 7/2/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
Unreliable. If you sync up at the beginning of a run, and then the
remote system executes a large clock step (e.g., because it's not
running NTP or it's misconfigured, or it is but NTP has bailed due to
excessive drift from hardware issues
On 7/2/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
I understand that it's a fairly low probability, and
depends on some questionable configurations, but rsync is well-known
to be both reliable and deterministic. I'd hate for something like
this to start chipping away at that reputation, even
On Sat, Jun 30, 2007 at 04:17:29PM -0400, Matt McCutchen wrote:
First, setting the xattr hits the file's ctime.
Yeah, I realize that, and that's why none of the xattr values cache the
ctime. This does mean that this method isn't good for updating checksum
values on existing files (since a
On 6/30/07, Wayne Davison [EMAIL PROTECTED] committed:
Added Files:
checksum-xattr.diff
Log Message:
A simple patch that lets rsync use cached checksum values stored in
each file's extended attributes. A perl script is provided to create
and update the values.
Wayne,
You should be
Matt McCutchen wrote:
Second, it is impossible to make xattr-based checksum caching
foolproof against same-second modification. Suppose a file is written
during second 5 and then rsync caches its checksum during second 8;
now the file has mtime 5 and ctime 8. Sometime later, rsync notices
