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
<jgeoghega...@gmail.com <mailto:jgeoghega...@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
