On Mon, Mar 31, 2003 at 01:31:50PM -0500, Matt Miller wrote:
I haven't tested it, but DOT 6.4 reports that it has:
Ability to convert a qtree to a rooted directory or convert a rooted directory to a qtree using either a Windows or UNIX client application
"...using either a Windows or UNIX client application" is the key part, here. UNIX 'mv' being one of the "client applications"... ;-) What this consists of is basically what Garrett seems to be trying to avoid:
(1) rename the directory (mv dir/ olddir/) (2) create a qtree with the name (qtree create dir) (3) copy the files over (mv olddir/* dir) (4) remove the directory (rm -rf olddir/)
The above procedure would consume 2X disk space of "dir" in step 3, and then throw EVERYTHING into a snapshot in step 4. ...not exactly what I'd call a "new feature"; presumably we were always able to do this...
---- Garrett, I've done 'mv' and ndmpcopy for dir->qtree and qtree->qtree. Of course, it doesn't really matter what the source IS (dir or qtree), just as long as its not being used (written to) at the time of transfer, otherwise it becomes a game of "catchup"... ;-)
For small chunks, 'mv' or 'rsync' seems to do best; I recommend 'rsync' (http://samba.anu.edu.au/rsync/) as it doesn't change file attributes on the target files. However, in regards to 'mv' vs. 'rsync', keep in mind that 'rsync' will run on the client, COPYing files from source to target with a just a bit more NFS overhead than regular 'mv' and a lot more overhead in the beginning to "build a list of files" to sync.
For big chunks, ndmpcopy seems to be the best option. However, keep in mind there is A BUTT LOAD of overhead involved. In a ndmpcopy local->local, the local machine is performing: (1) an NDMP session for the DUMP (2) a snapshot of the tree (3) a DUMP of the snapshot (4) an NDMP session for the RESTORE (5) pipe of the DUMP of the snapshot, through the local loopback (6) a RESTORE of above's data
rather than local->remote, where each machine would only be performing 3 of the 6 steps...
Garrett Burke wrote:
Hi,
Has anyone any experience of converting a directory to a qtree (we want to make use of the qtree to qtree snapmirror features in DOT 6.2 and greater)
There's a doc on NOW which gives two ways either do a copy, which requires enough free space (which we don't have) or to use the built in ndmpcopy feature of DOT.
There's also the possibility of doing a 'mv' on each file, although I'd be a bit concerned that this might leave the filesystem in a less than optiomal state on the filer.
I'd be interested in hearing from anyone who has done this, especially about throughput (The directories we need to convert have approx 150G of mail in them, so lots of small files, on a 840C)
--
Dave Le Blanc Unix Systems Administrator Computer Science Department California Institute of Technology (626)395-2402