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Re: Backup ideas

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On 2020-04-28 12:15, Default User wrote:

> I don't recall the specific error code I got; just that it refused to
> do a sync using the -x option.  

I keep a plain text system administration log file for each computer in 
CVS.  I cut and paste console sessions into it.  If a given command 
produces a lot of output, I paste it into a separate file or create the 
file with tee(1).


> And I can't try it now, as I am now
> into the 11th or 12th hour of rsyncing one external usb drive to
> another.  At this rate it could take days to complete!  I had no idea.

Use df(1) to find out how much data is on the source disk.


Install nmon(1) and use it to find out the transfer rate.  If you use 
the Xfce desktop, install the Disk Performance Monitor panel applet.


Divide the data size by the transfer rate to get an estimate of how long 
the transfer will take.  Understand that the transfer rate of HDD's 
slows down as the block number increases (transfer rate of the last 
block is about half that of the first block).


> Unfortunately, I only have one computer. 

Ouch.  You need another computer.  I would suggest a used server with 
ECC memory and a decent number of drive bays.  But, a $20 garage sale 
used tower is better than nothing.


> I am not on a LAN 

Assuming you have a residential broadband Internet connection, many 
gateways include a 4 port Gigabit switch and Wi-Fi.  If you have more 
than one device connected to the gateway/ Internet, you have a LAN.


> and have no NAS, etc. 

NAS devices give you functionality without having to understand the 
details.  If you want to understand the details, building your own file 
server with Debian and Samba is an intermediate-level project.


> And raid setups are "above my pay grade" anyway.

Setting up a mirror with md(4) and mdadm(8) is a beginner/ 
intermediate-level project.  If your one computer is a desktop and it 
has two spare bays, you should consider it.


> Question:
> 
> When you use rsync, do you ever do it on a live, mounted filesystem
> from within said machine/filesystem (that is, using the same machine)?
> 
> Or do you do it on a "dormant" unmounted filesystem, either from
> another machine or from a "live [usb or .iso] utility distribution or
> boot disk from which you have booted the same machine?
> 
> Most references to rsync I have seen just seem to accept as a given,
> that you are doing it remotely, from across a LAN (or across the
> world).
> 
> And don't seem to address whether the machine/filesystem they are
> rsyncing to/from is "live" (mounted), or can/should be unmounted (like
> it would be when imaging a disk with dd or Clonezilla, for example.

rsync(1) is for mounted filesystems.  If you need consistency of files 
and/or directories, the source filesystem should be mounted read-only. 
I use rsync(1) for data and for system configuration files.  I do not 
use rsync(1) to backup, restore, or migrate operating system images.


I use dd(1) to backup, restore, and migrate operating system raw drive 
images.  To make this practical, I keep my system images small enough to 
fit on a "16 GB" device (USB flash drive, SSD, HDD), and I do not use RAID.


It is useful to have a live Debian system on a USB flash drive for doing 
these kinds of operations.


David

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(none) Default User <hunguponcontent@gmail.com> - 2020-04-22 23:00 +0200
  Re: David <bouncingcats@gmail.com> - 2020-04-23 12:00 +0200
  Re: "Alexander V. Makartsev" <avbetev@gmail.com> - 2020-04-23 16:30 +0200
  Re: David Christensen <dpchrist@holgerdanske.com> - 2020-04-24 00:10 +0200
    Re: Default User <hunguponcontent@gmail.com> - 2020-04-24 03:00 +0200
      Re: David Christensen <dpchrist@holgerdanske.com> - 2020-04-24 11:00 +0200
      Backup ideas Andy Smith <andy@strugglers.net> - 2020-04-24 17:40 +0200
        Re: Backup ideas Celejar <celejar@gmail.com> - 2020-04-24 18:30 +0200
          Re: Backup ideas Default User <hunguponcontent@gmail.com> - 2020-04-28 17:50 +0200
            Re: Backup ideas Andrei POPESCU <andreimpopescu@gmail.com> - 2020-04-28 18:20 +0200
              Re: Backup ideas Default User <hunguponcontent@gmail.com> - 2020-04-28 20:30 +0200
                Re: Backup ideas Default User <hunguponcontent@gmail.com> - 2020-04-28 21:20 +0200
                Re: Backup ideas David Christensen <dpchrist@holgerdanske.com> - 2020-04-28 22:30 +0200
                Re: Backup ideas Bob Weber <bobrweber@gmail.com> - 2020-04-28 22:50 +0200
            Re: Backup ideas Bob Weber <bobrweber@gmail.com> - 2020-04-28 20:20 +0200
            Re: Backup ideas Andy Smith <andy@strugglers.net> - 2020-04-28 22:40 +0200
              Re: Backup ideas Celejar <celejar@gmail.com> - 2020-04-29 06:40 +0200
            Re: Backup ideas Celejar <celejar@gmail.com> - 2020-04-29 06:30 +0200
            Re: Backup ideas Alessandro Baggi <alessandro.baggi@gmail.com> - 2020-05-01 12:40 +0200
              Re: Backup ideas Default User <hunguponcontent@gmail.com> - 2020-05-04 03:30 +0200

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