在 2006-09-17日的 13:30 +0200，Patrick Ohly写道：
> On Sun, 2006-09-17 at 15:19 +0800, 张韡武 wrote:
> [incremental backups with multisession]
> > This is actually very convenient for me, each CDR is labeled with week
> > number and project category name. If the manager ask for files on Jan
> > 12th in the training project, I go to find the CDR in training project
> > backup CDs, find that week's backup, figure out 12th is a Thursday, thus
> > mount the 4th session.
>
> A while ago I wanted to do the same thing and to make it possible with
> mkisofs I added the --root/--old-root command line options. The only
> difference compared to your method is that each day ends up being a
> separate directory, so by mounting the last session you have access to
> each snapshot of the week at once. Unchanged files are still only stored
> on the disc once.
>
> These options are now included in the standard mkisofs. For a usage
> example see the attached script. It uses growisofs to burn writable DVD,
> but the same method also works with cdrecord + writable CD.
I discovered these options in the manual. In the beginning I thought
they were un-documented but actually they were documented. Thus no more
questions on how to use them.
It seems with this new method I don't have to mount n-th session to
recover backup, I just need to go to the directory. It also seems it is
not possible to actually remove a file from previous session by not
including it in the current directory, as suggested in the manual:
Without these options, new files would be added and old ones
would /be preserved/. But old ones would be overwritten if the
file was modified.
Just for exploring, I'll test a bit, using '/' as '-old-root' and do not
use '-root', if the old files would really be preserved even if they no
longer exist on hdd at the time of doing incremental backup.
>
--
锐业软服（国内业务） http://www.realss.cn
Real SoftService http://www.realss.com
销售咨询(Sales Department): 0086 592 20 99987 (Chinese, German,
English)
国际业务(International Sales): 0086 10 8460 6011 (German and English)
联系：厦门大学科技园，嘉庚二号楼6楼
邮政：厦门大学2312号信箱（邮编361005）
Attachment:
signature.asc
Description: =?UTF-8?Q?=E8=BF=99=E6=98=AF=E4=BF=A1=E4=BB=B6=E7=9A=84=E6=95=B0?= =?UTF-8?Q?=E5=AD=97=E7=AD=BE=E5=90=8D=E9=83=A8=E5=88=86?=