Possible to compress a TM backup file?
in [Mac Systems]
|
From: Mark Conrad on 29 Mar 2010 15:52 In article <5zr5n3t6wl.fsf(a)ethel.the.log>, Doug Anderson <ethelthelogremovethis(a)gmail.com> wrote: > > I have a friend who is a newbie to Macs, he uses > > Time Machine to create bootable backups. > > > > Those backup files occupy a tremendous amount > > of space. Compressing them would reduce their > > space by about half. > > This surprises me (that he can make bootable > backups with Time Machine). Strictly speaking, he can't, I was "lazy" in my wording, the backup files themselves are not bootable. I guess I should have posted that the he could restore the Mac drive to being bootable again, if the Mac OS was corrupted so badly that it would not boot. > Almost certainly if you compress the TM archive > from outside of TM, it will confuse TM, right? I guess that depends on the compression scheme, i.e. lossy versus non-lossy compression. I was thinking of off-site backups, in other words, compressed archive backups of the original backups, only to be used in case the original backups get lost or destroyed. Myself, I have none of these worries, because I use an off-beat backup/restore scheme. (terminals dd command) dd allows me to create backups/restores of any Windows partition on my Mac, along with the regular backups/restores of my Mac partition. Compressing backup files is also easy, usually saving about 50% on disk space. Bottom line, in the case of my friend, is to find some way, _any_ way, of compressing a TM file that does not want to be compressed.<g> Mark-
From: Mark Conrad on 29 Mar 2010 15:52 In article <290320101206002281%nospam(a)nospam.invalid>, nospam <nospam(a)nospam.invalid> wrote: > > Those backup files occupy a tremendous amount > > of space. Compressing them would reduce their > > space by about half. > > hard drives are cheap. Not _that_ cheap, I have lotsa drives, and am still short on drives. > > I have a friend who is a newbie to Macs, he uses > > Time Machine to create bootable backups. > > no he doesn't. time machine doesn't create > bootable backups. Well yes, strictly speaking, the backup file itself is not bootable, if that is what you mean. TM does the next best thing: 1) Erase your Mac's internal boot drive 2) Using your last complete back up from TM, follow TM's instructions for restoring your entire drive Your internal drive will now be bootable. Mark-
From: nospam on 29 Mar 2010 15:13 In article <290320101152076784%aeiou(a)mostly.invalid>, Mark Conrad <aeiou(a)mostly.invalid> wrote: > > > Those backup files occupy a tremendous amount > > > of space. Compressing them would reduce their > > > space by about half. > > > > hard drives are cheap. > > Not _that_ cheap, yes, _that_ cheap. > I have lotsa drives, and am > still short on drives. buy some more.
From: Doug Anderson on 29 Mar 2010 15:24 Mark Conrad <aeiou(a)mostly.invalid> writes: > In article <5zr5n3t6wl.fsf(a)ethel.the.log>, Doug Anderson > <ethelthelogremovethis(a)gmail.com> wrote: > > > > I have a friend who is a newbie to Macs, he uses > > > Time Machine to create bootable backups. > > > > > > Those backup files occupy a tremendous amount > > > of space. Compressing them would reduce their > > > space by about half. > > > > This surprises me (that he can make bootable > > backups with Time Machine). > > Strictly speaking, he can't, I was "lazy" in my > wording, the backup files themselves are not bootable. > > I guess I should have posted that the he could restore > the Mac drive to being bootable again, if the Mac OS > was corrupted so badly that it would not boot. > > > > > Almost certainly if you compress the TM archive > > from outside of TM, it will confuse TM, right? > > I guess that depends on the compression scheme, > i.e. lossy versus non-lossy compression. It might depend on the compression scheme, but just because the compression is non-lossy, it wouldn't automatically follow that TM knows what to do with the compressed files and/or folder. > I was thinking of off-site backups, in other words, > compressed archive backups of the original backups, > only to be used in case the original backups get > lost or destroyed. And then you would uncompress them before giving them back to TM? If that is what you are going to do, why don't you just use gzip and tar? They won't give you any confusing error messages. You'd want to use options that preserve all the various bits of information. [Of course like any backup scheme - test to make sure that restore works.]
From: =?ISO-8859-1?Q?Kir=E1ly?= on 29 Mar 2010 15:28
Mark Conrad <aeiou(a)mostly.invalid> wrote: > I was thinking of off-site backups, in other words, > compressed archive backups of the original backups, > only to be used in case the original backups get > lost or destroyed. Good idea. There are many backup programs that will do that for you. But Time Machine is not one of them. Abandon TM for Retrospect or something similar if you want the backups to compressed. -- K. Lang may your lum reek. |