Thank you very much for clarifying that for me! I really appreciate it.
This is one of the amazing things I love about OpenBSD- I asked a
question about softraid, and the actual dev who wrote the crypto
softraid code responds. God bless OpenBSD
On 04/28/18 06:05, Joel Sing wrote:
> On Friday 27 April 2018 11:17:07 Jordan Geoghegan wrote:
>> Thanks for the reply, I have rebuilt a softraid mirror before, I was
>> just hoping for some clarification as the faq wording is a little
>> ambiguous as to whether drives can be rebuilt in multi user mode or not.
> Rebuild is a background kernel operation - you can initiate it in either
> single user or multi user mode.
>
>> I was also curious how the system handles write operations to the array
>> while it is rebuilding.
> Writes go to chunks that are in an online or rebuilding state, while reads
> only come from online chunks. Other than the overhead from the background I/O
> there is no reason you cannot operate as normal during a rebuild.
>
>> Similarly, is the reboot required for the newly repaired array to be
>> initialized/function?
> The need to shutdown/reboot is really only hardware dependent - if you have
> hotplugable devices then there is no need to reboot - you can however reboot
> half way through a rebuild and it will pick up where it left off (providing the
> chunks are available).
>
>> I have a simple production storage NAS I am setting up, and would
>> appreciate any input on softraid "best practices".
> As per some previous advice test - build the volume, pull a disk (or bioctl -
> O), rebuild, etc - make sure you know how it is going to work before you put
> data on it.
>
>> On 04/26/18 17:48, IL Ka wrote:
>>> Hello,
>>>
>>> No, you do not need to reboot. At least this is how it worked for me
>>> for raid 1:
>>>
>>> 1) bioctl softraid0 said raid degraded
>>> 2) I installed new disk (sd2).
>>> 3) kenrel reported on console that disk is detected
>>> 4) I created MBR using fdisk on it
>>> 5) I created disklabel with RAID type on it
>>> 6) bioctl -R /dev/sd2a sd0
>>>
>>> I suggest you to try it yourself, but not on production system)
>>>
>>>
>>>
>>> On Fri, Apr 27, 2018 at 2:21 AM, Jordan Geoghegan
>>>
>>> <jgeoghegan60@gmail.com <mailto:jgeoghegan60@gmail.com>> wrote:
>>> Hello,
>>>
>>> Sorry for my ignorance, I was hoping someone could clarify for me
>>> the proper procedure for rebuilding a softraid mirror. The man
>>>
>>> page/faq says:
>>> Rebuilding a mirror
>>>
>>> When a drive failure happens, you will replace the failed
>>> drive, create the RAID and other disklabel partitions, then
>>> rebuild the mirror. Assuming your RAID volume is sd2 and you
>>> are replacing the failed device with sd1m, the following
>>> commands should work:
>>>
>>> #*bioctl -R /dev/sd1m sd2*
>>> #*reboot*
>>>
>>> These steps can be performed in either single user mode
>>> <https://www.openbsd.org/faq/faq8.html#LostPW
>>> <https://www.openbsd.org/faq/faq8.html#LostPW>> or from the
>>> install kernel <https://www.openbsd.org/faq/faq4.html#bsd.rd
>>> <https://www.openbsd.org/faq/faq4.html#bsd.rd>>.
>>>
>>> Does this mean that a RAID rebuild can *only* be performed from
>>> single user mode or install kernel, or is it possible to rebuild
>>> an array while the system is in full operation?
>>>
>>> To phrase my question a different way:
>>> Is it possible to hot swap drives and rebuild arrays on the fly,
>>> or will this bork my system?
>>>
>>> Thanks,
>>> Jordan Geoghegan
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