Marcus,
Holy moly, that is beautiful.
So glad to understand better what's in the box.
Also please note that I'm not trying to suggest to implement lots of
crap, am perfectly clear that high security is correlated with low
complexity.
On 2016-02-21 00:29, Marcus MERIGHI wrote:
ti...@openmailbox.org (Tinker), 2016.02.20 (Sat) 16:43 (CET):
..
You appear to mean bioctl(8). Thats the only place I could find the
word
'patrol'. bioctl(8) can control more than softraid(4) devices.
bio(4):
The following device drivers register with bio for volume
management:
ami(4) American Megatrends Inc. MegaRAID
PATA/SATA/SCSI RAID controller
arc(4) Areca Technology Corporation SAS/SATA RAID
controller
cac(4) Compaq Smart Array 2/3/4 SCSI RAID controller
ciss(4) Compaq Smart Array SAS/SATA/SCSI RAID
controller
ips(4) IBM SATA/SCSI ServeRAID controller
mfi(4) LSI Logic & Dell MegaRAID SAS RAID controller
mpi(4) LSI Logic Fusion-MPT Message Passing
Interface
mpii(4) LSI Logic Fusion-MPT Message Passing
Interface
II
softraid(4) Software RAID
It is talking about controlling a HW raid controller, in that 'patrol'
paragraph, isn't it?
So by this you mean that patrolling is really implemented for softraid??
(Karel and Constantine don't agree??)
So I just do.. "bioctl -t start sdX" wher sdX is the name of my softraid
device, and it'll do the "scrub" as in reading through all underlying
physical media to check its internal integrity so for RAID1C that will
be data readability and that checksums are correct, and "doas bioctl
softraid0" will show me the % status, and if I don't get any errors
before it goes back to normal it means the patrol was successful right?
(And as usual patrol is implemented to have the lowest priority, so it
should not interfere extreemely much with ordinary SSD softraid
operation.)
* Rebuild - I think I saw some console dump of the status of a
rebuild
process on the net, so MAYBE or NO..?
That's what it looks like:
$ doas bioctl softraid0
Volume Status Size Device
softraid0 0 Rebuild 12002360033280 sd6 RAID5 35% done
0 Rebuild 4000786726912 0:0.0 noencl <sd2a>
1 Online 4000786726912 0:1.0 noencl <sd3a>
2 Online 4000786726912 0:2.0 noencl <sd4a>
3 Online 4000786726912 0:3.0 noencl <sd5a>
Yey!!
Wait, can you explain to me what I would write instead of "device" and
"channel:target[.lun]" in "bioctl -R device" and "bioctl -R
channel:target[.lun]", AND what effect those would have?
Say that my sd0 and sd1 SSD:s run a RAID1C already, can I then make
softraid extend my RAID1C with my sd2 SSD by "rebuilding" it, as a way
to live-copy in all my data to sd2, so this would work as a kind of live
attach even if expensive?
Does it work for a softraid that's live already?
* Hotspare - MAYBE, "man softraid" says "Currently there is no
automated
mechanism to recover from failed disks.", but that is not so specific
wording, and I think I read a hint somewhere that there is hotspare
functionality.
bioctl(8)
-H channel:target[.lun]
If the device at channel:target[.lun] is currently marked
``Unused'', promote it to being a ``Hot Spare''.
That's the only mention of 'hot spare'. And again talking about
controlling a hardware RAID controller, isn't it?
What is 'not so specific' about 'no' (as in "Currently there is *no*
automated mechanism to recover from failed disks")?
Awesome.
I guess "bioctl softraid0" will list which hotspares there are
currently, and that "-d" will drop a hotspare.
The fact that there is hotspare functionality, means that there are
cases when softraid will take a disk out of use.
That will be when that disk reports itself as COMPLETELY out of use ALL
BY ITSELF, such as self-detaching itself on the level of the SATA
controller or reporting failure via some SMART command?
A disk just half-breaking with broken sectors and 99% IO slowdown will
not cause it to go offline though so I guess I should buy enterprise
drives with IO access time guarantees then.
* Hotswap - MAYBE, this would depend on if there's rebuild. Only
disconnect
("bioctl -O" I think; "bioctl -d" is to.. unmount or self-destruct a
softraid?)
bioctl -O should fail the chunk specified, simulating hardware failure.
After this command you have an 'Offline' chunk in the 'bioctl' output.
bioctl -d 'detach', not 'destroy'; just as sdX appears when you
assamble
a softraid volume, this makes it go away. better unmount before...
So "-d" is to take down a whole softraid. "-O" could work to take out a
single physical disk but it's unclean.
So then, there is a very unrefined hotswapping functionality in that
"-O" can be used to take out a single physical drive, and "-R" (if I
understood it correctly above) can be used to plug in a drive.
Preferable would be to "hotswap" the whole softraid by simply taking it
offline altogether ("bioctl -d [raid dev]") and then taking it online
altogether ("bioctl -c 1 -l [comma-separated devs] softraid0")
The man pages are sometimes over-minimalistic with respect to an
individual
user who's trying to learn, this is why I'm asking for your
clarification.
I am quite sure the man pages are kept as condensed as they are on
purpose.
You can always read mplayer(1) if you want something lengthy ;-)
So your clarifications would still be much appreciated.
Nothing authoritative from me!
I am just trying to flatten your learning curve.
Bye, Marcus
Awesome. Thank you so much!
