[mythtv-users] Spin up delay for HDDs

digid myth digidmyth at gmail.com
Mon Sep 26 14:19:07 UTC 2011

I have 9 drives in my system with a 400 watt PS, see my configuration at
http://www.gossamer-threads.com/lists/mythtv/users/492094#492094 I do not
come close to the limits of the power supply on boot, so you should not have
a problem.

Only two drives are in RAID which are used as a NAS, and not really used for
myth at all.

There is no need to use RAID with myth, Its built in storage groups work
great. If you build that big of a raid how are you going to back it up? If I
add a 2TB to my myth machine, I add a 2TB to my other machine to back it up
to. The other advantage of not putting your myth storage disks in raid is
that if you access one you only wake that drive up, not the whole raid. The
drives will also have a tendency to last longer not in a raid configuration
as they are sleeping most of the time. Think this out before you build a big
RAID array.

It is not uncommon to have a drive in a raid fail, and another fail when it
is trying to rebuild using a spare. Has happened many times. This is one of
the reasons commercial raid systems do not use large drives. It takes less
time to rebuild a failed drive with a smaller drive.  You did not say what
size drives you are using, but if you are going with 2tb drives the time to
build the raid is great. A 4 drive raid 5 with 2 TB drives will take over 1
day to build, or rebuild. I have 2 2TB drives in raid 1 for my data, with a
hot spare, but they are backed up to another machine, and the data is pretty
static. A cron job backs up changed files one a day to another machine.

At work we have some very large raid 10 arrays but none of the drives are
larger than 330G or so.

When I rebuild my myth server I will raid my boot drive/database drive,
currently it is not a raid set.

The only data I have ever lost has resided on RAID arrays! I look at RAID as
high availability, do not rely on using them as a way to backup your data.
you still need to plan for backups, for the data on the RAID.

I have been using Storage groups for 2 years in myth and have been very
happy with them. Personally I would not put myth video data on a RAID other
than OTA recordings.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.mythtv.org/pipermail/mythtv-users/attachments/20110926/08f85bc8/attachment.html 

More information about the mythtv-users mailing list