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
