Backup or archive? Command line or application?

English Applications
1

Hi Everyone,

I am hoping that someone can explain very easily to me which would be my best option.

My machine is dual boot on the primary drive, but over the past year I have only gone to windows for a music notation program and a family tree program.

My machine has two hard drives my second hard drive is fat32 and is shared with windows.

Once a month (I try to remember) to backup my /home directory to the second drive. Then about every three months I burn my /home directory onto dvd’s. Once a year I burn a copy of all my photographs taken during the year and send them to godmother in case my house burns down.

Over the years this has become more difficult as my /home directory appears to be so big.

I have been using tar cvf /windows/D/home.tar /home/nappy

I think I have also been using split, but because I only use it every few months, I am never really comfortable with it and I spend a day trying to get my head around what I need to do so I don’t mistype (I find using the command line quite frightening). I do like the idea that I can see all the files it is copying.

So I need to backup my data in my /home directory, in case my old machine dies, or for the next time I upgrade Suse.

So today when I started my /home directory was around 20gb. I have copied my movies, photos and documents folder, etc for the whole year onto my second drive and burned them to dvd. Also the hidden folder .thunderbird. I have deleted them from my primary drive, but not the .thunderbird. I have also emptied the trash.

So now when I check the properties on my /home directory it says:
5.4 GB
Free disk space 14.8 GB out of 28.6 GB (49%)

However when I check with a calculator I am using 13.8 GB of space?

In the past I have used tar and split, but I can’t find the piece of paper with the command written on and so it goes on…

I have found another thread which talks about ‘back in time’, luckybackup and rsnapshot.

So what is it I do? I think I am backing up. What do these applications do? and is it what I want?

It may sound a strange question, but they talk about snapshots and sync tool. I don’t really understand what that is or does. I take snapshots of my screen sometimes, I’m not sure how this relates to files/data?

Regards

nappy

P.S When I go to my computer I have noticed / has a red bar.
It says it has 319.4 MB left. It is a 16 GB drive, am I correct in thinking the / partition doesn’t get any bigger?

2

When you install software it goes to root (/) also temp files get written to /tmp (you might want to clean that up). There are certain databases that may be also on root by default. So root can grow.

You must be very careful about free space calculations. Some programs calculate the absolute number of bytes, others base calculation on blocks used. So it can be confusing.

Space is allocated to files in blocks. If even one byte of the file gets to a block no part can be used by other files thus can not be truly counted as free space. The percentage of these partial blocks is very dependent on the average size of the files. ie lots of little files will tend to have more wasted space then fewer large files.

When backing up to a archive file the total absolute file sizes are important. When talking file systems the block usage is ultimately more important.

How big is a block? depends on the disk typically 1024 but with the new huge drives this can be much more. So for the new super drives there is more wasted space for the same set of files.

3

Thanks for your reply. I thought it was growing. By clean up do you mean just delete the /tmp files? Or delete the /tmp files up to a certain date?

The only databases I create are the ones in OpenOffice.

You must be very careful about free space calculations. Some programs calculate the absolute number of bytes, others base calculation on blocks used. So it can be confusing.

Space is allocated to files in blocks. If even one byte of the file gets to a block no part can be used by other files thus can not be truly counted as free space. The percentage of these partial blocks is very dependent on the average size of the files. ie lots of little files will tend to have more wasted space then fewer large files.

When backing up to a archive file the total absolute file sizes are important. When talking file systems the block usage is ultimately more important.

How big is a block? depends on the disk typically 1024 but with the new huge drives this can be much more. So for the new super drives there is more wasted space for the same set of files.

I’m not sure I understand. My daughter (8) plays a game on her father’s laptop which is about running a diner. She has to sit groups of customers at 2 seat tables. As the game develops you then have tables that sit 4. I spend ages explaining to her that she should fill the 4 seat tables with 3 or 4 customers, rather than 2 then she may reach her quota as the game would not allow her to seat another 2 at a four seat table where 2 were already sitting.

So are you saying because there is one person at a 4 seat table no one else can sit there until they have gone? I know some of the files are not big, but the used space is more than double what it says? 5.4 GB against 13.8 GB?

Regards

4

So are you saying because there is one person at a 4 seat table no one else can sit there until they have gone? I know some of the files are not big, but the used space is more than double what it says? 5.4 GB against 13.8 GB?

Yep. If you have lots of little files that are not an integer of block size. You can accumulate lots and lots of wasted space. This is just how hard drives work and is system independent. The bigger the block size the more potential wasted space. You can not allocate space for a file smaller then the block size. Consider that if the block size is 1024 and the average file size is 512 then 1/2 the space available in bytes is wasted.

5

Seems to me that you’re not backing up often enough, and also that you’ve outgrown DVDs as a backup medium (they’re not that reliable anyway).
My suggestion would be to buy a USB external hard drive. They’re not that expensive, and more reliable (well they do fail but the USB drive and your main hard disk are unlikely to fail at the same time). Then use something like Backintime which will make an initial full backup, but after that only copy the files that have actually changed, thus saving space. A cheap 80Gb or so USB HD should go a long way, by what you have told us.

6

There’s a plan. I presume USB external hard drives just works? I don’t have to be careful what I buy, like trying to find a webcam that works?

Then use something like Backintime which will make an initial full backup, but after that only copy the files that have actually changed, thus saving space. A cheap 80Gb or so USB HD should go a long way, by what you have told us.

Thank you for your reply.

7

Yes, all USB hard drives work. If you have a spare HD lying around, you can just buy an enclosure of the same physical size.

8

I think I have a hard drive around somewhere, but I don’t think it was very big. That makes more sense to what I saw when I checked online.

There were a lot of enclosures with 2.5" or 3.5". I have never used one before so I assumed it was a complete unit, not a drive and enclosure. Actually it sounds like a caddy?

I have had some time to think about this now, which is probably a bad idea. If I get a 60 GB or 80 GB external hard drive and put my home directory on it once a month. It will fill up in about 7 or 8 months.

Then I presume I would start deleting the first home directory. So I would only have the last few months available. So I would still have to make a hard permanent copy of my photographs, music, movies and probably Thunderbird mail.

I can’t think why I would need to keep this data apart from restoring my machine after it breaks or when I upgrade, so maybe I don’t need to keep more than a few months?

Another thought is if I use one of the applications, I understand that it will only backup the files that have changed. So the backup will be a lot smaller, I assume? So I should get a lot more on it.

Another thought, people don’t use hard drives like permanent media, that is fill one up and then get another?

9

Something like Backintime (there are others) will only save files that have changed. So, for argument’s sake, if you start off with a /home of 20Gb, it will take those 20Gb on the backup but then only add the changes and additions.
Only you know how much data you create. Think about it and size your backup media accordingly.

10

Hi Everyone,

I have installed Back in Time on my machine and purchased a 160GB external hard drive.

The hard drive is FAT32, do I need to format it as something else?

Thank you everyone for their help.

Regards

11

nappy501 wrote:

> The hard drive is FAT32, do I need to format it as something else?

will you ever need to use with any OS that can not read ext3 or ext4??

–
palladium

12

Yes. FAT32 has all kinds of restrictions, caters for limited filesize, and doesn’t work well with rsync (which Backintime uses). EXT3 is best, but if you need to access it directly from a Windows machine you can get away with NTFS I believe.

13

Rather than focusing on the details like CLI or app, think about your backup strategy in general and what sequence events would follow if you had a failure. That will determine your strategy.

As an example here’s what I do:

I don’t backup the OS, I am prepared to reinstall from DVD if I lose the OS, since it doesn’t take long. Getting all updated might take a while, but it shouldn’t take me long to have something usable.

I do backup key files in /etc and other places that carry configuration information though to DVD-RW about once a quarter. Maybe I should do that more often.

I backup my home directory to an external disk once at midweek and to DVD-RW at weekend. The latter is automated from cron. My personal files, email, etc. still fit on a DVD.

Media and other stuff I archive to DVD-R while leaving them on disk (but not included in the regular backups).

One area in which I’m not well protected is offsite backups. I recently gave a friend an encrypted DVD of my personal files. Perhaps I should send out DVDs more often.

=====

External disks are good in that you can recover stuff quickly. Also you don’t have to split to multiple DVDs. They are bulkier than DVDs but not much nowadays.

You might want to think about having two external disks that you take offsite in rotation.

14

Hi

I have been away and checked what ext3 and ext4 mean.

I am going to go for ext3 (Random choice as I don’t know much about it). I am going to partition the disk with 20 or 30 gb as fat32, so I can back up my children’s machine which is running Windows XP.

That will leave 130 gb for my machine. One last question should I partition that as well? Is there any chance that part of the disk will fail? So I will save something if I partition it or should I just leave it as one big partition?

Thank you.

15

nappy501 wrote:
> I am going to go for ext3 (Random choice

i can’t see any logical reason to not choose ext3…
(ext4 is just barely out for non-beta use, in the last year…)

> One last question should I partition that as well? Is there any
> chance that part of the disk will fail? So I will save something
> if I partition it or should I just leave it as one big partition?

hmmmm, i’m not a real file system guru and can’t answer with cites…i
can tell you what i would do–leave all the ext3 as one partition…

yes, if that one partition table gets corrupted you are in for some
work…but what is to say the same bug/hardware/firmware fault would
corrupt only one of two or six partitions?

in all answers: listen to ken_yap (especially if he and i disagree,
i’m half way ok generalist…but, he is smart and has Linux experience
far beyond my own…)

–
palladium

16

I installed 11.2 with ext4. Would you advise the use of ext3 on an external HD for backups?