[Info-vax] backup /image on Windows or Unix?

[Jan-Erik Soderholm]

Jan-Erik Soderholm wrote 2013-01-23 16:35:
> Bill Gunshannon wrote 2013-01-23 16:27:
>> In article <kdorln$bsu$2 at dont-email.me>,
>>     Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>>> On 2013-01-23, Dirk Munk <munk at home.nl> wrote:
>>>> One of the nicest features of VMS is backup/image. Take a badly
>>>> fragmented disk as input, and you will get a beautiful structured disk
>>>> as output, all files contiguous etc.
>>>>
>>>> I have always been looking for utilities that can do the same in Windows
>>>> and Unix, but I never found them.
>>>>
>>>
>>> In Unix land have you considered a dump and restore sequence ?
>>
>> Or the fact that defragmentation is seldom if ever needed on Unix
>> filesystems.

One need a definition of "needed" here, I guess. :-)

I have never defragmented any VMS disk, or anyway, not in the
last 10-15 years. Current prod system has system and data disks
initiated in 1998 and 1999. DFU reports:

Syst disk: File fragmentation index: 7.526  (poor)
Data disk: File fragmentation index: 1.310  (good)

(I have no idea how *that* is calculated either... :-) )

I guess that could be improved anyway.

Anyway, with todays storage systems, the whole idea of
defragmentation has lost most of it's meening, I'd say.
There is some overhead with reading extentions, but most
of the additional disk-head latency isn't there anymore.

Jan-Erik.




>>
>> ** /dev/ad4s1a
>> ** Last Mounted on /
>> ** Root file system
>> 2138 files, 286668 used, 219819 free (2883 frags, 27117 blocks, 0.6%
>> fragmentati
>> on)
>>
>> ** /dev/ad4s1e
>> ** Last Mounted on /tmp
>> 18 files, 21 used, 506466 free (34 frags, 63304 blocks, 0.0% fragmentation)
>>
>> ** /dev/ad4s1f
>> ** Last Mounted on /usr
>> 511196 files, 9230891 used, 23406146 free (77194 frags, 2916119 blocks,
>> 0.2% fra
>> gmentation)
>>
>> ** /dev/ad4s1d
>> ** Last Mounted on /var
>> 28558 files, 91462 used, 2657823 free (23015 frags, 329351 blocks, 0.8%
>> fragment
>> ation)
>>
>> ** /dev/da0s1d
>> ** Last Mounted on /archive
>> 241149 files, 93064509 used, 143440310 free (9678 frags, 17928829 blocks,
>> 0.0% f
>> ragmentation)
>>
>> ** /dev/ar0s1d
>> ** Last Mounted on /users
>> 1128838 files, 150083077 used, 86421742 free (166710 frags, 10781879
>> blocks, 0.1
>> % fragmentation)
>>
>> bill
>>
>
> How is that "n.n % fragmentation calculated ?
>
>