Usb hdd and power failure

[noric]

I was wondering what's going to happen to the usb hdd in case of unexpected power failure. I remember that some time ago there was a problem of file system corruption every time the router turned off without unmounting the hdd. Is it still there? In case it's still there, how do you guys deal with it (I don't believe everyone use a UPS)?
Thanks for the info!

P.S.: for now, I've tested a reboot (from GUI and from telnet) without unmounting the hdd and it went well!

Edit: this must be what I remember: http://forums.smallnetbuilder.com/showpost.php?p=43838&postcount=30

 

[Lotta Cox]

Don't use computer or a router without a UPS.

 

[RMerlin]

I was wondering what's going to happen to the usb hdd in case of unexpected power failure. I remember that some time ago there was a problem of file system corruption every time the router turned off without unmounting the hdd. Is it still there? In case it's still there, how do you guys deal with it (I don't believe everyone use a UPS)?
Thanks for the info!

P.S.: for now, I've tested a reboot (from GUI and from telnet) without unmounting the hdd and it went well!

Edit: this must be what I remember: http://forums.smallnetbuilder.com/showpost.php?p=43838&postcount=30

Anytime a hard disk (or any storage device) is involved and there are potential write operations, unexpected power failures will always carry the risk of filesystem corruption. Hard disks for instance are using large caches to speed up write operations. The host (router or PC) will also have its own buffering system. If power gets cut before those buffers are written down to disk (or while in the middle of being written down), you can end up with damaged content.

Always keep backups of any stored data. If it's mission-critical, then install a UPS.

Data corruption on a reboot is an entirely different issue, that was resolved about two years ago.

 

[noric]

If power gets cut before those buffers are written down to disk (or while in the middle of being written down), you can end up with damaged content.

Ok, if I (or the system) am writing files (or the buffer isn't empty yet) I'm going to face data corruption, that's normal.
But the issue some time ago was far more dangerous than on a computer, because as they say in the post I linked you were ALWAYS (or very often) going to expect data (and usb apps) corruption on every power failure. This doesn't happen anymore, does it?

 

[RMerlin]

Ok, if I (or the system) am writing files (or the buffer isn't empty yet) I'm going to face data corruption, that's normal.
But the issue some time ago was far more dangerous than on a computer, because as they say in the post I linked you were ALWAYS (or very often) going to expect data (and usb apps) corruption on every power failure. This doesn't happen anymore, does it?

As noted at the end of my reply, data corruption caused by normal reboots was resolved nearly two years ago. This is what the linked thread was really about.

I don't remember anything mentioning systematic data corruption on every single power failure - that would require some writing to have occurred to cause it.

 

[noric]

Ok, thanks Merlin, that's what I hoped to hear!

 

[Trebuin]

I just found out that my external has a built in battery to protect itself during a power outage...no need for UPS unless there are writes going to it. The way I use this, I don't need one apparently. I've been trying to find a way to have the router shut down for a period during the night and shut down the drive. Now my plan is just to throw a wall timer on the master power and fully kill it during the night. Time to save 60watts an hour.

 

[Lotta Cox]

Which external had a battery?
Putting a timer might save you up to $1/mo. That would be at least year before you see any savings after paying for the timer. Not really worth it.

 

[Trebuin]

In an attempt to no advertise, the not so impressive Drobo is what I'm using. Does the job, but slow as dirt. Anyhow, at my calculation, it will save me apps $180 per year using a kilowatt meter:

65 watts/hr (cost of router, Drobo, and drives)
1560 watt/day
46800 watt/mo
46.8 kw/mo
$.32 per kw (PGE)
$14.976/mo
$179.71/yr just to operate.

That's why I'm trying to cut everywhere. I don't even run my computer much anymore.

 

[Lotta Cox]

Wow that is three times what I pay for elec from Baltimtimore Gas and Elec.

 

[KGB7]

In an attempt to no advertise, the not so impressive Drobo is what I'm using. Does the job, but slow as dirt. Anyhow, at my calculation, it will save me apps $180 per year using a kilowatt meter:

65 watts/hr (cost of router, Drobo, and drives)
1560 watt/day
46800 watt/mo
46.8 kw/mo
$.32 per kw (PGE)
$14.976/mo
$179.71/yr just to operate.

That's why I'm trying to cut everywhere. I don't even run my computer much anymore.

It wont save you anything as battery it self needs to be recharged. If a battery lasts 1 hour, it might take 4-6 hours to recharge.

Plus a battery has a life cycle of an average of 300 charges, depending on the battery. Once you run out of 300 charges, you have to buy a new battery. And a new battery is another drain in your pocket.

If you want to save money on electric bill, then turn off the external HDD when ever you are not using it. Might as well flush the toilet after you peed 3 times.

We pay around $200 a month in the summer time while A/C is running full time, that includes many electrical devices in the house.

So to say an external HDD costs you $180 a year to operate is far fetched.

It costs around $90 per year to run a refrigerator. http://blog.gvea.com/wordpress/?p=933
http://www.apartmenttherapy.com/you...-costing-you-a-lot-more-than-you-think-187189

 

[Trebuin]

I posted the exact numbers there, can't refute that. Maybe it would help if I told you I live in califonia. My bill is at $250 a month with only 1 hr max ac during the night to help he family go to sleep. First month surprise with. $450 electric bill with the ac set at 76f, and they want to increase the cost of power here. My bill in my Washington house was $60, 72f ac, same size house, max temp was in the high 80s to low 90s, not 95-110 during the summer. I'm military so I have no choice on where I live until the force shaping board. The drobo has five drives in it so that put the just that unit around 40-45 watts. Motor timers run around 10 watts. I should actually adjust the savings to aroun $40 a year because I'd probably have it running around 18 hrs in the day(almost not worth that effort, especially with burning the battery out). I'd probably be better off hooking it up to a kill switch with the rest of my equip or make sure it goes to sleep correctly. It took about a week of run time for it to start going to sleep. I have to hide it behind the of because my wife would overrule it as being an eye sore for her decor. I'm still thinking how to handle this and will eventually come up with something.

 

[oldgringo]

In an attempt to no advertise, the not so impressive Drobo is what I'm using. Does the job, but slow as dirt. Anyhow, at my calculation, it will save me apps $180 per year using a kilowatt meter:

65 watts/hr (cost of router, Drobo, and drives)
1560 watt/day
46800 watt/mo
46.8 kw/mo
$.32 per kw (PGE)
$14.976/mo
$179.71/yr just to operate.

That's why I'm trying to cut everywhere. I don't even run my computer much anymore.

I'm sorry, maybe I miss something, but...
Do you want completely shut down all these devices for 24 hrs/day? It seems like that from your calculation.

 

[Trebuin]

I'm sorry, maybe I miss something, but...
Do you want completely shut down all these devices for 24 hrs/day? It seems like that from your calculation.

I caught myself after the fact...thats why I said I'd probably only save $45 a year...cutting those off for only 6 hrs a day reduces those numbers. The digital timers are rather unreliable from what I'm finding and the analog ones use 10w of power.