Paulwood
Posts: 50
Joined: Mon Nov 04, 2013 10:30 am

MagPi 77 - 'Save It Now' article

Wed Jan 02, 2019 11:25 am

While I find the idea of this article is great, I have to say that I find the information presented seems to jump from one topic to another without cohesion. Even the 'Top Tip's left me confused.

The first two paragraphs are fine - explaining the topic and proposing a solution. But the third paragraph is where confusion starts to emerge.

Whether you’re copying to disk, or moving the backup to another machine, it’s best to make it as small as possible. So you’ll want to compress the file. We advise using the gzip compression format. You could go with xz or bzip2 compression (from tar, J or j options, respectively) for better compression to a smaller file size, but although alternatives to gzip save a little more space, they can take far longer to perform the compression.

In the middle of talking about compression formats, the author dumps in some information about 'tar' options. ??? Why? What does that have to do with the idea of this paragraph which is talking about compression formats. 'Tar' is a new term dumped in without any explanation of what it is. An other thing that is unclear, in this section, is if 'gzip', 'xz' and bzip2' are commands or options used in some other program ('tar' for example).

Doing a test on my Pi, I entered 'gzip' 'xz' and 'bzip2' and while 'gzip' and 'bzip2' return messages indicating they exist, 'xz' returns '-bash: xy: command not found' so it is not a command/program(?) installed by default. confusion reigns.

The rest of the article and even some of the 'Top Tip's have issues. Take the first one:

Tape archive
Tar dates from the days when computers backed up to big tape reels, those essential props
of 1960s and 1970s sci-fi films. The lack of file structure on tapes means that tar can save all of the file system info such as ownership and timestamps.

This makes it sound like I need a tape drive to use tar!

I could go on, but I don't have the time. I think this article should have passed by an editor and changed before going into the MagPi.

And once again, I really like the idea of the article, I just think it needs some changes to make it a great reference guide.

hippy
Posts: 5353
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

Re: MagPi 77 - 'Save It Now' article

Wed Jan 02, 2019 12:50 pm

Paulwood wrote:
Wed Jan 02, 2019 11:25 am
In the middle of talking about compression formats, the author dumps in some information about 'tar' options. ??? Why? What does that have to do with the idea of this paragraph which is talking about compression formats. 'Tar' is a new term dumped in without any explanation of what it is. An other thing that is unclear, in this section, is if 'gzip', 'xz' and bzip2' are commands or options used in some other program ('tar' for example).
I would have worded it slightly differently; "So you'll want to compress the file. We recommend using the tar program with the gzip compression format. You could use xz or bzip2 compression (using tar options J or j respectively) for better compression which gives a smaller file size but these can take far longer to complete".

The only real issue IMO is in not having introduced the tar program as the way to do it.

I'm not saying your complaint isn't valid; it obviously did confuse you. But on the other hand it's not reasonable to expect everything to always be 100% perfect and crystal clear for everyone. But I am sure those involved in MagPi production strive towards that and your feedback will be taken on-board.

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rpdom
Posts: 14451
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: MagPi 77 - 'Save It Now' article

Wed Jan 02, 2019 1:07 pm

Paulwood wrote:
Wed Jan 02, 2019 11:25 am
This makes it sound like I need a tape drive to use tar!
What? You don't have one? (yes, I have a few right next to me - can't use them directly from a Pi though :lol: )
I agree that the article might have been worded better, but it is difficult to cover every possibility.

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