--- On Mon, 7/9/09, Majed B. <majedb@xxxxxxxxx> wrote: > From: Majed B. <majedb@xxxxxxxxx> > Subject: Re: Array Power Management > To: "jahammonds prost" <gmitch64@xxxxxxxxx> > Cc: linux-raid@xxxxxxxxxxxxxxx > Date: Monday, 7 September, 2009, 10:57 AM > If you're going to spin down the > disks, you'd need to unmount the > array first to ensure your data is fine, and after a > spin-up then you > mount the array again. > > I would suggest you buy a meter to measure how much power > your storage > is consuming before you decide on your next action. > > Personally, I'd turn off the machine altogether if it's not > needed > during working hours (assuming no one accesses through > VPN). Check the > BIOS, it may have the capability to wake up the machine on > a certain > date & time (So you can specify to turn itself on daily > @ 8 AM). > If not, you should have Wake-up On LAN support, so if you > turn off the > machine, another machine (a monitoring server) can turn it > on for you > (just put the wake-up on LAN command as a cron job to > execute daily -- > perhaps exclude holidays). > > On Mon, Sep 7, 2009 at 6:48 AM, jahammonds prost<gmitch64@xxxxxxxxx> > wrote: > > I've been becoming interested in the power consumption > of the arrays I have on a couple of servers here that are > basically used as media servers. Since they're not being > used when I'm at work, I was looking at the possibility of > spinning the disks down during certain times, and having > them either spin up at a set time, or (ideally), when there > is disk activity. > > > > I can do this on single drives using hdparm -S to set > the spindown timeout, and the disks will spin up on activity > as needed. Is there something similar I can do with an md > array? I can see there's a /sys/block/md0/power/wakeup file, > but I can't seem to find any documentation on it. I have > thought about doing an hdparm -S on the array disks, but I > suspect that would be A Bad Thing (tm). > > > > Does anyone have any advice/pointers? The servers are > currently running fc9 - I'd like them to be Centos, but had > to go with fc9, as I needed Port Multiplier support. > > > > > > Graham > > > > > > > > -- > > To unsubscribe from this list: send the line > "unsubscribe linux-raid" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > > -- > Majed B. > -- > To unsubscribe from this list: send the line "unsubscribe > linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > This is interesting.. I have the -S set for all my 6 drives in the array and have for some time and I do not unmount the array - access wakes the drives up - usually most of them, sometimes only a few of them. The only part of this that has caused me any problems are scheduled smartd checks - these cause timeout errors. The timeout is between 30mins and 1hr as if it is over 1 hour smart will keep them awake forever. In my case, if they are not used for 30mins; they wont be used for several hours. ----------------------- N: Jon Hardcastle E: Jon@xxxxxxxxxxxxxxx 'Do not worry about tomorrow, for tomorrow will bring worries of its own.' ----------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
