Force uncompress for data migration

[mufka]

It's been a long time since I've had to migrate a Netware volume to another server. I remember it taking forever to copy data from a compressed volume. Is there a way to force all the compressed files to uncompress first to speed the move? This assumes, of course, that the existing volume is big enough to hold all of the uncompressed data. Further, if I can uncompress the files, is there a way to prevent them from compressing again? I'm thinking that I might uncompress everything over a weekend and them move the data the following weekend.

 

[goombawaho]

From here:

http://www.novell.com/documentation/nw51/?page=/documentation/nw51/trad_enu/data/hiba3s9w.html

Disabling File Compression

File compression is enabled and disabled at the volume level.

If you do not enable file compression when you create a volume, you can subsequently enable it using the SET utility. Once enabled, however, file compression cannot be disabled on the volume unless you re-create the volume.

You can temporarily suspend file compression using the SET command's Enable File Compression parameter. (For a general description of the SET command, see SET in Utilities Reference in the NetWare 5.1 online documentation.)



I would say your best bet is if your backup software has an option to decompress upon backup. I know arcserve did when I was using it for Netware backup and was moving from traditional to NSS volumes. You could directly restore the data from a traditional compressed volume to an NSS volume.

 

[mufka]

I had read that, thanks. I was hoping there might be some undocumented magic. I don't think my backup software will do it, or at least I can't find it in there. That would be troublesome anyway because I'm going to a Windows server with different backup software. I don't want to muck it up with a trial version of Arcserve to restore it.

 

[goombawaho]

Best bet is to put another hard drive into the machine, create a new volume without compression and copy the data over to it. Then you'll have uncompressed data which you can copy.

 

[marvhuffaker]

There is an option that will tell it to decompress the file on the first access. By default, it won't do this till you access the file 2 or 3 times. I can't remember the option, but if you go through Monitor --> Server Parameters, there is a whole section of options related to compression and they are pretty straight forward.

So the trick would be to set the parameter, then access each file. A good way to force access to each file would be to use a program like Beyond Compare.. and do a binary comparison of pretty much anything. Perhaps even the destination file system whether the files are there or not.

The thing I do not know -- does 'accessing' the file mean simply reading the file in a directory listing or does it actually have to 'read/open' the file? I think the latter. Which is why just doing a "DIR /S" at the root level will probably not achieve the desired results.



Marvin Huffaker, MCNE
Marvin Huffaker Consulting, Inc.
A Novell Platinum Partner

http://www.redjuju.com