[RudyRedNose]

I am planning to build a Linux home server to serve all the computers in the house. Key points:

- Samba server (most clients are Windows)

- UPnP server

- Mythtv backend

- Mythtv occasional front end (during the debugging phase)

- Core2Quad Q8300 w 4G RAM on an EVGA_113-YW-E115-TR motherboard

- 160G system disk

- RAID 5 data disks (5x 1TB)

- Lots of expansion (Norco RPC4020 case with up to 21 HD)

- Remote management (this will live in the mechanical room)


I am planning to use the LinuxMint 10 distro, then add MythTv.


I would really like to get some advice or pointers on combining software Raid (madm) and energy saving configuration (shutdown/hibernate and WOL) on a modern kernel (2.6.35).


As this server will be fairly powerful and power-hungry, I want it to auto shutdown (preferably) or hibernate after 1 hour of no activity. On a client, I would usually start by sending the WOL packet to the server, and then start my client applications after a minute or 2.


Do you care to share your experience on combining energy savings and Raid ?


Thank you !


Rudy

 

[blackoper]

I went a different route and have a dedicated low power NAS that runs Freenas with 5x 2TB drives and a hotspare (spundown). I didn't like the delay when I spun all the drives down so I eat the 25 watts combined they pull in idle. My Nas idles at about 50-55 watts. My mythtv server is a Via system that uses the NAS for storage and has a low power laptop drive I had lying around. It has a digital tuner pci card, an analog pci card and a hdpvr through usb. Idle power is another 40 watts. My cost's for power are about $1 per watt over the course of a year (6.5 cents per KW)

http://www.mythtv.org/wiki/User:Blackoper

 

[RudyRedNose]

Blackoper, for simple NAS, your choice is more sensible, but I want to run ad scrubbing which I hear is fairly compute hungry. I have the parts and want to put them to good use hence my quest for hibernation/Raid combo...

I can live with the startup delays as I do not intend to run a web server running 24/7.


However, I am very concerned about the interactions of hibernation and Raid, so I am asking for advice.


Thank you


Rudy

 

[MichaelZ]

Quote:

Originally Posted by RudyRedNose Blackoper, for simple NAS, your choice is more sensible, but I want to run ad scrubbing which I hear is fairly compute hungry. I have the parts and want to put them to good use hence my quest for hibernation/Raid combo... I can live with the startup delays as I do not intend to run a web server running 24/7. However, I am very concerned about the interactions of hibernation and Raid, so I am asking for advice. Thank you Rudy

I am running 6 2TB drives for storage (non-raid) and I backup important stuff to two different drives (running cron scripts) and the rest of the static data I backup to older drives that I no longer use (except for that purpose). I allow all the drives to spin down since I use a SSD as boot and it stores frequently accessed data, like mail, web stuff, etc. On the SSD it also contains symlinks to the data across the 6 drives, allowing remote users to browse the catalogs without causing the actual drive to spin up as well as keeping easier to maintain samba shares. This keeps my machine from constantly waking the drives. The drives are active at least once per week via cron script and scanned for errors. So far, everything works great and I have been setup like this for a couple of years now.

I used to use hardware based raid5 but it seems a shame to have all those drives spinning for no real reason. Hardware based raid5 system can not be in sleep mode - at least all the ones I've tried. I did try using software raid5 and you can get the drives to suspend but any time you need something it spins them all up. So, I decided to do something a bit simpler.

 

[Fake Shemp]

Next month I will have run Linux software RAID 24/7 at home for two years. I use Debian and six SATA II drives in RAID-6. I don't hibernate the whole system or use WoL, but I do make the drives in the array spin down after an hour of inactivity. Since I don't run any processes that access the RAID frequently this effectively keeps the drives asleep 99% of the time.


I have never had any problems with mdadm, lvm or anything else playing nicely with the spun down drives. The only tedious part of setting it up was making an init script so that hdparm would run on boot (and set the drives to spin down).