Beware the cron jobs!

Discussion about hard drive spin down (standby) feature of NAS.
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pingu
Starting out
Posts: 33
Joined: Tue Sep 04, 2007 4:35 pm

Beware the cron jobs!

Post by pingu » Thu Sep 27, 2007 4:03 pm

So the standard cron jobs that are run on my TS-209 are:

File /etc/config/crontab:

# m h dom m dow cmd
0 3 * * * /usr/local/sbin/ImR_all -soft /Qmultimedia
0 5 * * * /etc/init.d/ddns_update.sh
0 4 * * * /sbin/hwclock -s

ALL of these processes will wake the nas up from standby in the middle of the night at 3am, 4am and 5am (as configured)
If you do not need/want these to run, either comment out each line (with a '#') or stop the cron daemon from running:
1) run /etc/init.d/crond stop
2) remove the Sxxcrond file from /etc/rcS.d/ - where xx is the startup priority

Alternatively you can change the schedule so they run less frequently.

ImR_all
=====
The ImR_all process is the 'thumbnailer'. That is, it will recurse the given folder (Qmultimedia here) and generate thumbnail images. Note that if you browse in MultmediaStation, it will do it there and then for the folder you're browsing. I guess this job is here to do the work overnight so you can instantly see all the thumbnails.
Be aware however, that it is very slow, if you've got thousands of photos, it will take many hours.
I don't mind this being done manually when I actually browse a folder for the first time, so I'd rather do that than have it wake up every night.

ddns_update.sh
==========
If you're using DDNS on the NAS, this runs to update your DDNS provider if you're IP has changed.
My router does my DDNS for me, so not needed.

hwclock
=====
The -s option indicates that this option is resetting the System Time from the hardware clock. This happens on startup and I'm not all that sure why it needs to happen every night, especially if you've enabled NTP.

HTH,
pingu

rogdog
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Posts: 1
Joined: Wed Oct 31, 2007 4:51 am

Re: Beware the cron jobs!

Post by rogdog » Tue Nov 06, 2007 6:30 pm

Thanks for the info. very useful :D

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