tzdata and tzdata-java

charliwest wrote:
Does anyone know if these are safe updates on a readynas nv+ v2?

Those updates should be fine; the tzdata and tzdata-java packages are just data files containing time-zone and daylight-savings-time (aka "summer time") information, so their periodic updates contain only rare (and usually small) changes -- spelling of place names, new DST-start and -end dates, etc. Everything you could possibly want to know about those files is here: https://www.iana.org/time-zones.

However... As you know (because you wouldn't be asking the question otherwise), the operating system in the ReadyNAS is not just standard off-the-shelf Debian. It has been carefully customized for this particular application, so operations that are usually safe on desktop Linux -- like regularly updating all your system software -- aren't necessarily safe for the NAS. I guess the rest of this post isn't for you, but for anyone who was surprised by the previous sentence in this paragraph.

If you want to be as safe as possible when updating, you should start by learning exactly what the update changes. Actually, that isn't true; you really should start by making sure that your backups are current. But after that, your next step is to learn what the update changes:

First, find the version numbers of your currently installed tzdata and the new tzdata. One easy way to do this is by performing a SIMULATED upgrade using the "-s" switch:

apt-get -s install tzdata

You'll see something like this, which shows what will happen if you do it again without the "-s" switch:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
  tzdata
1 upgraded, 0 newly installed, 0 to remove and 6 not upgraded.
Inst tzdata [2006c.netgear2] (2013b.netgear1 5.3.9)
Conf tzdata (2013b.netgear1 5.3.9)

The currently installed version is in square brackets: [2006c.netgear2]. The new version is in parentheses (2013b.netgear1). Those are just example version numbers, by the way; I don't know what versions are actually used by or available for your NV+.

To discover what changed between the two versions, look at the package's Debian changelog. The tzdata changelog is here: http://metadata.ftp-master.debian.org/changelogs//main/t/tzdata/tzdata_2013i-1_changelog.

After examining the changelog, you can then decide whether you need the upgrade. In general, my advice is to install updates only if they solve a problem that you are actually experiencing, but I know that it is often hard to resist the urge to update just because the new version is newer. If it helps, remember that with few exceptions, even the newest updates available for your NAS are still years old.