Possible to compress a TM backup file?
in [Mac Systems]
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From: Kevin McMurtrie on 29 Mar 2010 23:08 In article <290320101933474949%aeiou(a)mostly.invalid>, Mark Conrad <aeiou(a)mostly.invalid> wrote: > In article <290320101520212552%aeiou(a)mostly.invalid>, Mark Conrad > <aeiou(a)mostly.invalid> wrote: > > > > 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.] > > > > That sounds good at least for gzip. > > I tried gzip on regular files, works great, however I > could not get it to work on the TM file, despite trying > all the gzip options such as -r (recursive) > > gzip kept complaining that the TM file was not a > regular file. <g> > > Oh well... > > Mark- I don't think recursive gzip works. The 'tar' command has built-in bzip2 with the 'j' or 'y' option and gzip with the 'z' option. bzip2 makes smaller files but compression is very slow. tar -jcvf FOO.sparsebundle.tar.bz2 \ -C /Volumes/backupvolume \ FOO.sparsebundle -- I won't see Google Groups replies because I must filter them as spam
From: David Empson on 30 Mar 2010 00:20 nospam <nospam(a)nospam.invalid> wrote: > In article <hornm832tkm(a)news4.newsguy.com>, J.J. O'Shea > <try.not.to(a)but.see.sig> wrote: > > > >> Isn't the sparse image compressed? > > > > > > no. > > > > My error then. It's still a damn stupid thing to try. If he wants to > > compress the backup, use a backup system that does that automatically. > > Retrospect, for example. > > i've seen instructions on how to get time machine to use an encrypted > image (which time machine should do on its own, there's no excuse for > that), so it's probably possible to get it to use a compressed image. Nope. Compressed images are read-only, and are typically created using a two step process (create a regular image, then compress it). You temporarily need disk space to hold the entire uncompressed image, plus the compressed one. The resulting image might work for restoring a backup, but it would have to be converted back to a regular disk image or sparse image in order for Time Machine to add anything to the backup. Use Retrospect or buy a bigger hard drive. -- David Empson dempson(a)actrix.gen.nz
From: Mark Conrad on 30 Mar 2010 13:19 Just a few points of information - My friend has already bought "Superduper!" and actually created a backup of one of his Macs. (he is primarily a Windows user) But try as I might, I can't get him to test that backup. Now we all know, or _should_ know, that backups should be tested, if for no other reason than the backup may have been done wrong, so will not work when needed. So I walked him through using TM as a backup/restore program, demonstrating it on my own MacBook Pro. After creating the TM backup file, I then completely erased the internal hard drive of my MacBook Pro. ....then completely restored the drive by using the TM backup file. I finally convinced him (I think) - to actually test his TM backup, which is more than he will do with his "Superduper" backup. I agree that TM is far from being an ideal backup/restore app', but if it will get my friend to actually _test_ his backup, then I am all for it. I think that is kinda what Apple had in mind, among other features of TM, to enable everyone to create a whole-disk backup, even if they were "frightened" about using more suitable conventional backup applications like Superduper, Retrospect, etc. Mark-
From: Nick Naym on 30 Mar 2010 16:00 In article 300320100919204279%aeiou(a)mostly.invalid, Mark Conrad at aeiou(a)mostly.invalid wrote on 3/30/10 1:19 PM: > > Just a few points of information - > > My friend has already bought "Superduper!" and > actually created a backup of one of his Macs. > (he is primarily a Windows user) > > But try as I might, I can't get him to test that backup. > > Now we all know, or _should_ know, that backups > should be tested, if for no other reason than the > backup may have been done wrong, so will not work > when needed. > > > So I walked him through using TM as a backup/restore > program, demonstrating it on my own MacBook Pro. > > After creating the TM backup file, I then completely > erased the internal hard drive of my MacBook Pro. > > ...then completely restored the drive by using the > > TM backup file. > > I finally convinced him (I think) - to actually test his > TM backup, which is more than he will do with > his "Superduper" backup. > > There really isn't much to test: Just boot from the drive; if it boots, and if a Get Info says it's the same size (within a few bytes), it's an identical clone. You can scan the entries in the SD! log to see if there were any hiccups along the way, and the Shirt-Pocket discussion forum is an incredible resource for getting help (actually, it's more like a place you go to ask the developer questions: the developer is seemingly _always_ there, and _always_ provides help...better than almost any other vendor I've ever dealt with). > > I agree that TM is far from being an ideal backup/restore > app', but if it will get my friend to actually _test_ his > backup, then I am all for it. > > I think that is kinda what Apple had in mind, among other > features of TM, to enable everyone to create a whole-disk > backup, even if they were "frightened" about using more > suitable conventional backup applications > like Superduper, Retrospect, etc. > > Mark- -- iMac (27", 3.06 GHz Intel Core 2 Duo, 4 GB RAM, 1 TB HDD) � OS X (10.6.3)
From: Jim Gibson on 1 Apr 2010 18:13
In article <300320100919204279%aeiou(a)mostly.invalid>, Mark Conrad <aeiou(a)mostly.invalid> wrote: > Just a few points of information - > > My friend has already bought "Superduper!" and > actually created a backup of one of his Macs. > (he is primarily a Windows user) > > But try as I might, I can't get him to test that backup. > > Now we all know, or _should_ know, that backups > should be tested, if for no other reason than the > backup may have been done wrong, so will not work > when needed. > > So I walked him through using TM as a backup/restore > program, demonstrating it on my own MacBook Pro. > > After creating the TM backup file, I then completely > erased the internal hard drive of my MacBook Pro. > > ...then completely restored the drive by using the > TM backup file. > > I finally convinced him (I think) - to actually test his > TM backup, which is more than he will do with > his "Superduper" backup. Your friend is wise to ignore your method of testing his backups. By making a single backup, then erasing his hard drive, he is putting all of his data at risk. While it is good to test backups, you should try restoring to a _third_ disk and booting off of that, without erasing the original. If your friend made some mistake in setting up SuperDuper! and did not succeed in making a proper backup, your method of testing will ensure that his entire disk is wiped out! -- Jim Gibson |