No, lvm/dm-raid does not queue synchroniation.
If multiple raid1/4/5/6/10 LVs have their image LVs share the same
PV, resyncs will happen in parallel on all respective RAID LVs if requested.
E.g. (see Cpy%Sync field of the created 2 raid1 LVs):
LV VG Attr LSize SSize SRes Cpy%Sync Type #Cpy
#Str Stripe SSize PE Ranges
r1 r Rwi-a-r--- 512.00m 128 18.75 raid1 2
2 0.03m 128 r1_rimage_0:0-127 r1_rimage_1:0-127
[r1_rimage_0] r iwi-aor--- 512.00m 128 linear 1 0m
128 /dev/sdf:1-128
[r1_rimage_1] r iwi-aor--- 512.00m 128 linear 1 0m
128 /dev/sdg:1-128
[r1_rmeta_0] r ewi-aor--- 4.00m 1 linear 1
0m 1 /dev/sdf:0-0
[r1_rmeta_1] r ewi-aor--- 4.00m 1 linear 1
0m 1 /dev/sdg:0-0
r2 r Rwi-a-r--- 512.00m 128 31.25 raid1 2
2 0.03m 128 r2_rimage_0:0-127 r2_rimage_1:0-127
[r2_rimage_0] r iwi-aor--- 512.00m 128 linear 1 0m
128 /dev/sdf:130-257
[r2_rimage_1] r iwi-aor--- 512.00m 128 linear 1 0m
128 /dev/sdg:130-257
[r2_rmeta_0] r ewi-aor--- 4.00m 1 linear 1
0m 1 /dev/sdf:129-129
[r2_rmeta_1] r ewi-aor--- 4.00m 1 linear 1
0m 1 /dev/sdg:129-129
Though there's no automatic queueing of (initial) resynchronizations,
you can create the 2 LVs sharing the same PVs with the "--nosync"
option, thus preventing
immediate resynchronization and then "lvchange --syncaction repair
r-r1", wait for it to
finish and "lvchange --syncaction repair r-r2" afterwards.
Or create all but 1 LV with "--nosync", wait for the one to finish
before using lvchange
to start resynchronization.
BTW:
When you create a raid1/4/5/6/10 LVs _and_ never read what you have not
written,
"--nosync" can be used anyway in order to avoid the initial
resynchronization load
on the devices. Any data written in that case will update all
mirrors/raid redundancy data.
Heinz
On 09/30/2015 03:22 PM, Brassow Jonathan wrote:
I don’t believe it does. dm-raid does use the same RAID kernel personalities as MD though, so I would think that it could be added. I’ll check with Heinz and see if he knows.
brassow
On Sep 26, 2015, at 10:49 AM, Richard Davies <richard@xxxxxxxxxxxx> wrote:
Hi,
Does dm-raid queue resyncs of multiple dm-raid1 arrays, if the underlying
block devices are the same?
Linux md has this feature, e.g.:
# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
md1 : active raid1 sda2[2] sdb2[1]
943202240 blocks [2/1] [_U]
[====>................] recovery = 21.9% (207167744/943202240)
finish=20290.8min speed=603K/sec
bitmap: 1/8 pages [4KB], 65536KB chunk
md0 : active raid1 sda1[2] sdb1[1]
67108736 blocks [2/1] [_U]
resync=DELAYED
bitmap: 1/1 pages [4KB], 65536KB chunk
After some time investigating, I can't find it in dm-raid.
Please can someone tell me if this is implemented or not?
If it is implemented, where should I look to see it happening?
Thanks,
Richard.
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
