Bristol Digest, Vol 556, Issue 8

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Today's Topics:

1. Re: Is it harder on computer to stay powered up, or hibernate
often? (Amias Channer)
2. Re: Is it harder on computer to stay powered up, or hibernate
often? (Jamie Lokier)
3. Re: LUG Meeting this Saturday! 28/06/14 (Peter Hemmings)
4. Re: Raspberry pi controlling remote power sockets -
views/experience? (eddie smith)
5. Re: Raspberry pi controlling remote power sockets -
views/experience? (Ben Everard)


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Message: 1
Date: Thu, 26 Jun 2014 13:51:57 +0100
From: Amias Channer <me@amias.net>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Is it harder on computer to stay powered up, or
hibernate often?
Message-ID:
<CAMgU7XUSZNPVt6G+=bJHY5k_xdhxwqb=VfJcHF0QNJM0g+ZpVA@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Reet luggers,

i have a hunch that suspending and resuming might not be great for SSD's as
they can have quite a limited amount of writes before failing compared to
HDDs . Some basic models are really quite shocking so check for long term
reviews before buying cheap ssd's.
but then i am testing enterprise grade storage systems these days so my
'limited' might not be the same as yours.

If you have 16GB of ram and suspend that is quite a lot of data , i guess
you'd not be helping longevity much if you didn't expect the machine to
write 16gb in the time span it was suspend for if it wasn't suspended ,
which i would imagine is the majority of cases.

That said , SSD's speed makes suspend and resume so smooth it makes me
wonder if its actually done it most of the time.

The other benefit of SSD's (at the moment) is that they are small so they
kind of imply using external storage which will actually increase
reliability by providing some redundancy , something that previous hdd
owners might have passed up on. I think its a good thing to expect your
disk to fail and ensure you are covered rather than hoping it wont and
losing data.

Toodle-pip
Amias
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Message: 2
Date: Thu, 26 Jun 2014 18:16:39 +0100
From: Jamie Lokier <jamie@shareable.org>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Is it harder on computer to stay powered up, or
hibernate often?
Message-ID: <20140626171638.GC6568@jl-vm1.vm.bytemark.co.uk>
Content-Type: text/plain; charset=us-ascii

Amias Channer wrote:
> Reet luggers,
> i have a hunch that suspending and resuming might not be great for
> SSD's as they can have quite a limited amount of writes before failing
> compared to HDDs . Some basic models are really quite shocking so check
> for long term reviews before buying cheap ssd's.
> but then i am testing enterprise grade storage systems these days so my
> 'limited' might not be the same as yours.

There was a study recently, which tested lots of different SSDs
writing continuously over months, and found most of them, but not all,
tolerated a lot more writes than their specification implies.

> If you have 16GB of ram and suspend that is quite a lot of data , i
> guess you'd not be helping longevity much if you didn't expect the
> machine to write 16gb in the time span it was suspend for if it wasn't
> suspended , which i would imagine is the majority of cases.

If you have that much RAM, and don't churn through that much data
between suspendings, I'd hope the OS was smart enough to not rewrite
what it had already stored a copy of in swap space from the previous
hibernate.

> That said , SSD's speed makes suspend and resume so smooth it makes me
> wonder if its actually done it most of the time.

With SSD there's no advantage to restore that part of RAM which is
filesystem cache and mapped files, which for most users with a lot of
RAM is likely to be nearly all of it. The effect is like doing a
filesystem cache flush, but the SSD is so fast subsequently that you
hardly notice. With a HDD, it's more of a compromise, because doing
that after resume results in a lots of slow seeking as soon as you
continue doing things.

The same applies to application memory which is swapped out for
hibernate. There's no advantage to swapping it all back in on resume
with SSD; pages might as well be fetched on demand, about as quickly.

That's all theory; I don't know what the various OSes actually do.

On a Macbook, it doesn't even write to storage straight away on
suspend. First it suspends to RAM, then silently commits to storage
after a little while, so you don't see the process taking time. That
gives you a combintion of benefits, and is very sensible, but I don't
know if the other OSes have adopted it. I always worried it might be
not very safe waking the HDD while it's jiggling about in a backpack;
but with SSD that's not a worry.

> The other benefit of SSD's (at the moment) is that they are small so
> they kind of imply using external storage which will actually increase
> reliability by providing some redundancy , something that previous hdd
> owners might have passed up on.

SSDs aren't all small :)

-- Jamie



------------------------------

Message: 3
Date: Thu, 26 Jun 2014 20:09:41 +0100
From: Peter Hemmings <peter@hemmings.eclipse.co.uk>
To: Ben Everard <ben_everard@yahoo.com>, Bristol and Bath Linux User
Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] LUG Meeting this Saturday! 28/06/14
Message-ID: <53AC6FF5.5060900@hemmings.eclipse.co.uk>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Sorry I cannot make it this month.

On 25/06/14 12:43, Ben Everard wrote:
> Hello,
>
> I'm Ben (one of the team from Linux Voice magazine-
> www.linuxvoice.com). I'm in the process of moving to Bristol at the
> moment, and should be in town on 28th, so I'll try and make it.
>
> See you there,
>
> Ben Everard ben_everard@yahoo.com
>

I was just looking through some pi solutions on remote control of power
sockets (other thread) and found "Energenie Pi-mote". After realizing I
need (even at my age) some basic python experience, I found this book
recommended:

"Learning Python with Raspberry Pi" by Alex Bradbury and Ben Everard.

I now know who to ask if I get stuck!

Welcome to the list - see you next time



Regards
--
Peter H



------------------------------

Message: 4
Date: Thu, 26 Jun 2014 22:09:44 +0100
From: eddie smith <lug@eddiesmith.net>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Raspberry pi controlling remote power sockets -
views/experience?
Message-ID:
<CAGFc5Q3a6-zrOFzCemRfzdn7Ugfvj0mWGFAYszj_3=38_tDO=g@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8

There is the pi-mote

http://www.raspberrypi.org/controlling-electrical-sockets-with-energenie-pi-mote/

Available here

https://energenie4u.co.uk/index.php/catalogue/product/ENER002-2PI

On Thu, Jun 26, 2014 at 9:38 AM, Amias Channer <me@amias.net> wrote:
> i'm not using that anymore but if i was i'd put open-wrt on it.
>
>
> On 25 June 2014 15:17, Zak Wilcox <iwilcox@iwilcox.me.uk> wrote:
>>
>> On 25/06/14 14:28, Amias Channer wrote:
>> > if you are still using the netgear dg834g then it definitely can.
>>
>> If you're still using a DG834G connected to the InterEvil then I hope
>> you've checked it for security bugs like TCP-32764, plus maybe WPS
>> bruteforce unless your neighbours are saints.
>>
>>
>> _______________________________________________
>> Bristol mailing list
>> Bristol@mailman.lug.org.uk
>> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
>
>
> _______________________________________________
> Bristol mailing list
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> https://mailman.lug.org.uk/mailman/listinfo/bristol



------------------------------

Message: 5
Date: Fri, 27 Jun 2014 09:30:53 +0100
From: Ben Everard <ben_everard@yahoo.com>
To: Bristol and Bath Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Raspberry pi controlling remote power sockets -
views/experience?
Message-ID:
<1403857853.30150.YahooMailNeo@web172301.mail.ir2.yahoo.com>
Content-Type: text/plain; charset="iso-8859-1"

Hi,

The manufacturer's have just agreed to send me a pi-mote and some sockets to review for Linux Voice. I can let you know what they're like.
?

Ben Everard
ben_everard@yahoo.com
+44 (0) 7923409265


On Thursday, 26 June 2014, 22:11, eddie smith <lug@eddiesmith.net> wrote:



There is the pi-mote

http://www.raspberrypi.org/controlling-electrical-sockets-with-energenie-pi-mote/

Available here

https://energenie4u.co.uk/index.php/catalogue/product/ENER002-2PI

On Thu, Jun 26, 2014 at 9:38 AM, Amias Channer <me@amias.net> wrote:
> i'm not using that anymore but if i was i'd put open-wrt on it.
>
>
> On 25 June 2014 15:17, Zak Wilcox <iwilcox@iwilcox.me.uk> wrote:
>>
>> On 25/06/14 14:28, Amias Channer wrote:
>> > if you are still using the netgear dg834g then it definitely can.
>>
>> If you're still using a DG834G connected to the InterEvil then I hope
>> you've checked it for security bugs like TCP-32764, plus maybe WPS
>> bruteforce unless your neighbours are saints.
>>
>>
>> _______________________________________________
>> Bristol mailing list
>> Bristol@mailman.lug.org.uk
>> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
>
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol

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End of Bristol Digest, Vol 556, Issue 8
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