Good morning Phil and whomever
On Wed, Nov 4, 2015 at 7:13 AM, Phil Turmel <philip@xxxxxxxxxx> wrote:
> Good morning Dee, Brad,
>
> On 11/04/2015 07:02 AM, o1bigtenor wrote:
>> On Tue, Nov 3, 2015 at 10:31 PM, Brad Campbell
>
>>> Here's how I do it. This script is run on every bootup.
>
> A few notes here for Dee:
>
> Running this script (or something similar) needs to be automatic. In
> older systems, that means including it in /etc/rc.local. That file is
> deprecated in some modern systems, and alternates vary by distro. I
> don't know what you should use in Debian 8. {It still exists and works
> in Ubuntu Server 14.04.}
I used to have to mount my raid array on every reboot so I can handle running
the script every reboot. They happen at most weekly and for sure biweekly
because Firefox doesn't know how to use AND release RAM.
>
>>> It iterates through all the drives and uses smartctl to try and set erc
>>> timeouts. If that fails it assumes the drive does not support it and it sets
>>> the timeout value to 180 seconds.
>>>
>>> #!/bin/bash
>>> for i in /dev/sd? ; do
>
> This iterates through all sata drives, whether raid or not.
>
>>> if smartctl -l scterc,70,70 $i > /dev/null ; then
>>> echo -n $i " is good "
>
> "Good" clearly means the device has ERC support and the default timeout
> is OK.
>
>>> else
>>> echo 180 > /sys/block/${i/\/dev\/}/device/timeout
>>> echo -n $i " is bad "
>
> "Bad" means it doesn't support ERC, so the timeout is set to the
> work-around 180 seconds. That's the best you can do for such drives.
>
>>> fi;
>>> smartctl -i $i | egrep "(Device Model|Product:)"
>
> Your output was scrambled a bit at the end because a couple devices
> didn't report model or product, which Brad relied on for a end-of-line
> character.
Those 2 drives are in a separate USB connected tray.
When I ran the smartctl* command that you had me run to check the status
and configuration of the drives it borked on that drive telling me that it was
connected using USB and I needed to add some other command.
>
>>> blockdev --setra 1024 $i
>>> done
>>>
>>> I have a mix of 15k SAS drives, WD green & red and some left over bits and
>>> pieces. This ensures the timeouts all match the drives capability.
>
> Looks pretty good to me.
Those are the drives Brad uses.
>
>> ran the script
>
>> /dev/sda is bad Device Model: ST1000DM003-1ER162
>> /dev/sdb is good Device Model: ST31000524AS
>> /dev/sdc is bad Device Model: ST1000DM003-1ER162
>> /dev/sdd is bad Device Model: Corsair Force 3 SSD
>> /dev/sde is good Device Model: ST31000524AS
>> /dev/sdf is good Device Model: ST31000524AS
>> /dev/sdg is bad /dev/sdh is bad
>
>> As sdh is supposed to be a NAS drive I'm now confused.
>
> The script doesn't care what the drives are used for -- it just picked
> out all that start with 'sd'.
>
>> Is there anything that can be done to the drives already owned?
>
> Already done by the script. Not ideal, but not catastrophic.
>
>> How does one find applicable hard drives?
>> Only buy Enterprise class drives?
>
> { This was in your reading assignments. You may need to re-read them. I
> suggest you subscribe to this list -- let the normal flow of questions
> and answers help teach you the concepts underneath all of this advice.
> Anyways, }
I read the files listed.
There wasn't anything specific as to what to look for.
There is a lot of traffic which isn't really of interest as I hope that I don't
have to develop kernel skills. Was hoping to just occasionally browse
something that would be of interest.
Have looked for recommendations as to what is a good layout for an
array and have found little guidance. At present I am thinking that Raid
10 on 4 drives offers me the best security (if the drives don't act stupid)
for the amount of storage I see needing.
Any suggestions for which level of raid to use for ??? ?
>
> Buy drives that clearly indicate 'raid' or 'enterprise' support, or have
> OEM datasheets that explicitly show ERC support.
>
> My latest purchases have been Western Digital "Red" drives. They are
> marketed to home & small business NAS applications. I'm sure other
> brands are now targeting that market, too.
The last drives I bought, for use in a NAS box, are WD Red drives.
sdh is one of those drives - - - that's why I was asking if I had to buy
Enterprise drives. The tariff there is substantial - - - maybe your group can
come up with something to return to the idea RA Inexpensive drives.
Dee
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