[Dirvish] Copying dirvish vaults (heavily hard linked)

Shawn (Red Mop) redmopml at comcast.net
Thu Mar 6 16:33:52 UTC 2008


On Thursday 06 March 2008 09:21:53 am Keith Lofstrom wrote:
> A reminder - using any file-level tool (like rsync or cp or dump or
> tar) to copy a complete Dirvish vault, with tens or hundreds of images
> hard-linked together, may take a very long time.  Even though the
> final result (preferably using rsync) will be a similar collection
> of hard-linked files of the same size (with only the date stamps on
> the soft-linked files different), the system at the sending end will
> have to walk through every one of the source images.  This can take
> many days or even weeks.
>
> It can be easier to just copy the partition as a binary file, then
> use some tool to resize it at the target end.  I am learning about
> lvm and the Redhat tool resize2fs (which I just used to double the
> size of an active partition - scary!), and will try them on a
> dirvish bank soon.
>
> See also the ancient:  http://wiki.dirvish.org/index.cgi?CopyingDisks
>
> Keith

Tar is actually very fast.  I used it to split a bank about a month ago.  It 
was a little unnerving, so I ran rsync -aH on top of (after) tar, and rsync 
did almost nothing.  The du -hcs * in each vault already matched.

LVM + resize2fs is one of my very best friends.  I grow and shring partions 
all the time.  It's a real kick to move a partition from one disk to another 
while the partition is in use without rebooting, or even taking the partition 
offline.


More information about the Dirvish mailing list