Synology DiskStation Manager (DSM) allows you to back up a machine running Apple OS X via Time Machine to a Synology NAS device. This lets you back up many computers running OS X to a single NAS.
OS X support for NAS devices has improved in recent years. Time Machine attempts to mount the NAS volume, mount the sparsebundle file, then backup into the sparsebundle.
The problem
It seemed to work for a few months after I set it up, but in the last half of 2016 I started seeing corrupted backup messages from OS X:
The last time I used Evernote on my Mac was Evernote 4.3.1 (circa 2012 I believe). I had accumulated over 5000 notes. In an act of supreme cleverness, instead of actually archiving those notes in the Evernote enex format, I just backed up my entire home directory, knowing that all my notes were safely stored somewhere in the ~/Library hierarchy.
When I finally got enough gumption on my new laptop to install Evernote, I found that the latest version could not read the native 4.3.1 format from the ~/Library hierarchy. Doom.
For several weeks I’ve had a 69 GB chunk of disk missing. No scanner could detect where it had gone (DaisyDisk, WhatSize, Finder, “About This Mac → Storage”, Disk Utility (also in Recovery mode), command-line utilities df and du): they all indicated that there was only 18G left and none of them could tell me where the missing 69G was.
I have an encrypted boot volume and thought that perhaps something had been corrupted, but I wasn’t sure. I haven’t ever seen anything like this before. I remembered fsck from my happy FreeBSD days, so I thought I would single-user boot and run an fsck_hfs to see what might come up, but first I needed to figure out which disk was the right one to scan; Disk Utility helped with that: select the primary volume (mine is the default “Macintosh HD”) and notice the “Device” in the bottom left corner: disk1
Apple removed the OpenSSL header files in “El Capitan”, making it hard to build OpenSSL-dependent libraries without modifying your system a little bit.
Fortunately we have Homebrew; if you don’t have it yet, go ahead and install it now. I’ll wait here.
Ready? Now, repeat after me:
$ brew doctor (now fix anything that it tells you to fix)
$ brew update
$ brew upgrade
We’re just warming up with all that; it’s good to stay current with things like OpenSSL, which tends to go stale fast. Now let’s install it:
I made these notes as a result of my experimentation with a Raspberry Pi. I kept messing up the software on the SD card and needed to start over, but it took a long time to go through all of the RPi setup steps. By copying the partitions, I was able to restore relatively quickly.
Get the info of each partition you want to copy on your SD card using diskutil: