ZFS: moving data

[Manojav Sridhar]

I have pool called atacama, it contains a folder called "media". I want to move this to a data set instead of having in the global zone.

is there is a quick way to do this?

so

moving from atacama/media to dataset called "atacama/media"

[Andre Lue]

fastest way probably
mv media omedia
zfs create options atacama/media
mv omedia/* media

or rsync

[Manojav Sridhar]

Post by Andre Lue
fastest way probably
mv media omedia
zfs create options atacama/media
mv omedia/* media
or rsync

that is what i tried but aborted soon because i saw the free space shrinking.

Will that cost me drive space. My drive is about 80% full, will the move still work okay?

[Manojav Sridhar]

Doing the move now .. why is this not a O(1) operation? does it involve actual moving?

[Andre Lue]

Since they are in the same filesystem only the inode table is updated (hence speed) but I'd have to double check with the whole Copy on Write thing since you are are > 80% utilized. I think it will require some space for the operation even a rm when the filesystem is full. Keep this link handy in case it does

http://sites.google.com/site/eonstorage/faq#TOC-Why-can-t-I-delete-files-when-no-sp

[Manojav Sridhar]

yup you were right. it ran out of space. got half a move done.. :-) lucky i still have my original data on a disk. Will do a rsync to the right data set in the mirror this time

[Manojav Sridhar]

yup you were right. it ran out of space. got half a move done.. :-) lucky i still have my original data on a disk. Will do a rsync to the right data set in the mirror this time

i have not snapshots or anything. So it don't think its actually possible to do.

[Manojav Sridhar]

crud.. i did have snapshot taken! which explains why it ran out of mem! gotta learn somehow i guess! thanks for the link

[Manojav Sridhar]

Post by Andre Lue
Since they are in the same filesystem only the inode
table is updated (hence speed) but I'd have to double
check with the whole Copy on Write thing since you
are are > 80% utilized.

This is much slower than a "move" its probably like you say a copy then delete, so its only proceeding slowly.


capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
atacama 616G 80.1G 234 1.75K 15.6M 6.07M
atacama 616G 80.1G 72 107 107K 13.0M
atacama 616G 80.1G 99 90 129K 11.2M
atacama 616G 80.0G 277 1.62K 30.1M 10.2M
atacama 616G 80.0G 65 113 95.2K 13.9M
atacama 616G 80.0G 139 1012 167K 13.1M

not sure why its only reading at 13.1, its a SATA2 drive connected to a Dual core Mobo...

I dont have zfs enabled. anything else i should be checking?

NAME USED AVAIL REFER MOUNTPOINT
atacama 624G 67.2G 443G /atacama
atacama/media 178G 67.2G 178G /atacama/media

[Manojav Sridhar]

dre2kse,

any ideas as to why it taking days (3+) to move 1.1TB of data from a global pool to a dataset?

[Andre Lue]

My guess is probably because the pool is greater than 80% filled. Copy on write by nature will need space to work. The tight space remaining to work is probably causing the bottleneck.

[Manojav Sridhar]

I'll buy that for now. Thanks!

[Andre Lue]

You can run diskspeed.sh to get an idea of the upper limit capabilities of your drives. I also have to offer this caution that it could be off or add more load to your already loaded disks as they may be hard at work, hence the numbers reported may be off.

[Manojav Sridhar]

getafix:19:/#diskspeed.sh
c0t0d0 67 MB/sec - USB
c1t0d0 24 MB/sec - USB
c2t0d0 24 MB/sec - USB (OS USB Key)
c3t0d0 104 MB/sec ( SATA2 DISK)
c3t1d0 96 MB/sec ( SATA2 DISK)

but the pool in which the mv is happening is not so hot..


getafix:4:~#zpool iostat -v sahara 2
capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
sahara 1.11T 257G 24 196 1.55M 586K
mirror 1.11T 257G 24 196 1.55M 586K
c0t0d0 - - 12 23 793K 586K
c1t0d0 - - 12 23 794K 586K
---------- ----- ----- ----- ----- ----- -----

capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
sahara 1.11T 257G 82 674 201K 1.44M
mirror 1.11T 257G 82 674 201K 1.44M
c0t0d0 - - 31 51 76.2K 1.44M
c1t0d0 - - 50 212 155K 5.42M
---------- ----- ----- ----- ----- ----- -----

capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
sahara 1.11T 257G 26 191 2.95M 420K
mirror 1.11T 257G 26 191 2.95M 420K
c0t0d0 - - 14 19 1.46M 421K
c1t0d0 - - 12 3 1.50M 16.0K
---------- ----- ----- ----- ----- ----- -----

capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
sahara 1.11T 257G 148 2 372K 16.8K
mirror 1.11T 257G 148 2 372K 16.8K
c0t0d0 - - 74 2 187K 16.8K
c1t0d0 - - 73 2 184K 16.8K
---------- ----- ----- ----- ----- ----- -----

[Andre Lue]

I did a check on the copy vs move and they both write the data again seemingly because of the COW (copy on write nature)

here's the copy (diff seems it does a read first):
./iosnoop
UID PID D BLOCK SIZE COMM PATHNAME
500 890 R 4413696 65536 cp <none>
500 890 R 4390145 131072 cp <none>
500 890 R 4390401 131072 cp <none>
500 890 R 4390657 131072 cp <none>
500 890 R 4390913 131072 cp <none>
500 890 R 4391169 131072 cp <none>
500 890 R 4391425 131072 cp <none>
500 890 R 4391681 131072 cp <none>
0 796 R 4391937 131072 zpool-abyss <none>
0 796 R 4392193 131072 zpool-abyss <none>
0 796 R 4392449 131072 zpool-abyss <none>
0 796 R 4392705 131072 zpool-abyss <none>
0 796 R 4392961 131072 zpool-abyss <none>
0 796 R 4393217 131072 zpool-abyss <none>
0 796 R 4393473 131072 zpool-abyss <none>
0 796 R 4393729 131072 zpool-abyss <none>
0 796 R 4393985 131072 zpool-abyss <none>
0 796 R 4394241 131072 zpool-abyss <none>
0 796 R 4394497 131072 zpool-abyss <none>
0 796 R 4394753 131072 zpool-abyss <none>
0 796 R 4395009 131072 zpool-abyss <none>
0 796 R 4395265 131072 zpool-abyss <none>
0 796 R 4395521 131072 zpool-abyss <none>
0 796 R 4395777 131072 zpool-abyss <none>
0 796 R 4396033 131072 zpool-abyss <none>
0 796 R 4396289 131072 zpool-abyss <none>
0 796 R 4396545 131072 zpool-abyss <none>
0 796 R 4396801 131072 zpool-abyss <none>
0 796 R 4397057 131072 zpool-abyss <none>
0 796 R 4397313 131072 zpool-abyss <none>
0 796 R 4397569 131072 zpool-abyss <none>
0 796 R 4397825 131072 zpool-abyss <none>
0 796 R 4398081 131072 zpool-abyss <none>
0 796 R 4398337 131072 zpool-abyss <none>
0 796 R 4398593 131072 zpool-abyss <none>
0 796 R 4398849 131072 zpool-abyss <none>
0 796 R 4399105 131072 zpool-abyss <none>
0 796 R 4399361 131072 zpool-abyss <none>
0 796 R 4399617 131072 zpool-abyss <none>
0 796 R 4399873 131072 zpool-abyss <none>
0 796 R 4400129 131072 zpool-abyss <none>
0 796 R 4400385 131072 zpool-abyss <none>
0 796 R 4400641 131072 zpool-abyss <none>
0 796 R 4400897 131072 zpool-abyss <none>
0 796 R 4401153 131072 zpool-abyss <none>
0 796 R 4401409 131072 zpool-abyss <none>
0 796 R 4401665 131072 zpool-abyss <none>
0 796 R 4401921 131072 zpool-abyss <none>
0 796 R 4402177 131072 zpool-abyss <none>
0 796 R 4402433 131072 zpool-abyss <none>
0 796 R 4402689 131072 zpool-abyss <none>
0 796 R 4402945 131072 zpool-abyss <none>
0 796 R 4403201 131072 zpool-abyss <none>
0 796 R 4403457 131072 zpool-abyss <none>
0 796 R 4403713 131072 zpool-abyss <none>
0 796 R 4403969 131072 zpool-abyss <none>
0 796 R 4404225 131072 zpool-abyss <none>
0 796 R 4404481 131072 zpool-abyss <none>
0 796 R 4404737 131072 zpool-abyss <none>
0 796 R 4404993 131072 zpool-abyss <none>
0 796 R 4405249 131072 zpool-abyss <none>
0 796 R 4405505 131072 zpool-abyss <none>
0 796 R 4405761 131072 zpool-abyss <none>
0 796 R 4406017 131072 zpool-abyss <none>
0 796 R 4406273 131072 zpool-abyss <none>
0 796 R 4406529 131072 zpool-abyss <none>
0 796 R 4406785 131072 zpool-abyss <none>
0 796 R 4407041 131072 zpool-abyss <none>
0 796 R 4407297 131072 zpool-abyss <none>
0 796 R 4407553 131072 zpool-abyss <none>
0 796 R 4407809 131072 zpool-abyss <none>
0 796 R 4408065 131072 zpool-abyss <none>
0 796 R 4408321 131072 zpool-abyss <none>
0 796 R 4408577 131072 zpool-abyss <none>
0 796 R 4408833 131072 zpool-abyss <none>
0 796 R 4409089 131072 zpool-abyss <none>
0 796 R 4409345 131072 zpool-abyss <none>
0 796 R 4409601 131072 zpool-abyss <none>
0 796 R 4409857 131072 zpool-abyss <none>
0 796 R 4410113 131072 zpool-abyss <none>
0 796 R 4410369 131072 zpool-abyss <none>
0 796 R 4410625 131072 zpool-abyss <none>
0 796 R 4410881 131072 zpool-abyss <none>
0 796 R 4411137 131072 zpool-abyss <none>
0 796 R 4411393 131072 zpool-abyss <none>
0 796 R 4411649 131072 zpool-abyss <none>
0 796 R 4411905 131072 zpool-abyss <none>
0 796 R 4412161 131072 zpool-abyss <none>
0 796 R 4412417 131072 zpool-abyss <none>
0 796 R 4412673 131072 zpool-abyss <none>
0 796 R 4412929 131072 zpool-abyss <none>
0 796 R 4413185 131072 zpool-abyss <none>
0 796 R 4413442 131072 zpool-abyss <none>
0 796 W 7349299 131072 zpool-abyss <none>
0 796 W 7349811 131072 zpool-abyss <none>
0 796 W 7349555 131072 zpool-abyss <none>
0 796 W 7350067 131072 zpool-abyss <none>
0 796 W 7350323 131072 zpool-abyss <none>
0 796 W 7350579 131072 zpool-abyss <none>
0 796 W 7351062 131072 zpool-abyss <none>
0 796 W 7351318 131072 zpool-abyss <none>
0 796 W 7351574 131072 zpool-abyss <none>
0 796 W 7352210 131072 zpool-abyss <none>
0 796 W 7352466 131072 zpool-abyss <none>
0 796 W 7352722 131072 zpool-abyss <none>
0 796 W 7348598 6144 zpool-abyss <none>
0 796 W 7348611 1024 zpool-abyss <none>
0 796 W 7348617 10752 zpool-abyss <none>
0 796 W 7352978 131072 zpool-abyss <none>
0 796 W 7353234 131072 zpool-abyss <none>
0 796 W 7353490 131072 zpool-abyss <none>
0 796 W 7353746 131072 zpool-abyss <none>
0 796 W 7354002 131072 zpool-abyss <none>
0 796 W 7354258 131072 zpool-abyss <none>
0 796 W 7354514 131072 zpool-abyss <none>
0 796 W 7354770 131072 zpool-abyss <none>
0 796 W 7355026 131072 zpool-abyss <none>
0 796 W 7355282 131072 zpool-abyss <none>
0 796 W 7355538 131072 zpool-abyss <none>
0 796 W 7355794 131072 zpool-abyss <none>
0 796 W 7356050 131072 zpool-abyss <none>
0 796 W 7356306 131072 zpool-abyss <none>
0 796 W 7356562 131072 zpool-abyss <none>
0 796 W 7356818 131072 zpool-abyss <none>
0 796 W 7357074 131072 zpool-abyss <none>
0 796 W 7357330 131072 zpool-abyss <none>
0 796 W 7357586 131072 zpool-abyss <none>
0 796 W 7357842 131072 zpool-abyss <none>
0 796 W 7358098 131072 zpool-abyss <none>
0 796 W 7358354 131072 zpool-abyss <none>
0 796 W 7358610 131072 zpool-abyss <none>
0 796 W 7358866 131072 zpool-abyss <none>
0 796 W 7359122 131072 zpool-abyss <none>
0 796 W 7359378 131072 zpool-abyss <none>
0 796 W 7359634 131072 zpool-abyss <none>
0 796 W 7359890 131072 zpool-abyss <none>
0 796 W 7360146 131072 zpool-abyss <none>
0 796 W 7360402 131072 zpool-abyss <none>
0 796 W 7360658 131072 zpool-abyss <none>
0 796 W 7360914 131072 zpool-abyss <none>
0 796 W 7361170 131072 zpool-abyss <none>
0 796 W 7361426 131072 zpool-abyss <none>
0 796 W 7361682 131072 zpool-abyss <none>
0 796 W 7361938 131072 zpool-abyss <none>
0 796 W 7362194 131072 zpool-abyss <none>
0 796 W 7362450 131072 zpool-abyss <none>
0 796 W 7362706 131072 zpool-abyss <none>
0 796 W 7362962 131072 zpool-abyss <none>
0 796 W 7363218 131072 zpool-abyss <none>
0 796 W 7363474 131072 zpool-abyss <none>
0 796 W 7363730 131072 zpool-abyss <none>
0 796 W 7363986 131072 zpool-abyss <none>
0 796 W 7364242 131072 zpool-abyss <none>
0 796 W 7364498 131072 zpool-abyss <none>
0 796 W 7364754 131072 zpool-abyss <none>
0 796 W 7365010 131072 zpool-abyss <none>
0 796 W 7365266 131072 zpool-abyss <none>
0 796 W 7365522 131072 zpool-abyss <none>
0 796 W 7365778 131072 zpool-abyss <none>
0 796 W 7366034 131072 zpool-abyss <none>
0 796 W 7366290 131072 zpool-abyss <none>
0 796 W 7366546 131072 zpool-abyss <none>
0 796 W 7366802 131072 zpool-abyss <none>
0 796 W 7367058 131072 zpool-abyss <none>
0 796 W 7367314 131072 zpool-abyss <none>
0 796 W 7367570 131072 zpool-abyss <none>
0 796 W 7367826 131072 zpool-abyss <none>
0 796 W 7368082 131072 zpool-abyss <none>
0 796 W 7368338 131072 zpool-abyss <none>
0 796 W 7368594 131072 zpool-abyss <none>
0 796 W 7368850 131072 zpool-abyss <none>
0 796 W 7369106 131072 zpool-abyss <none>
0 796 W 7369362 131072 zpool-abyss <none>
0 796 W 7369618 131072 zpool-abyss <none>
0 796 W 7369874 131072 zpool-abyss <none>
0 796 W 7370130 131072 zpool-abyss <none>
0 796 W 7370386 131072 zpool-abyss <none>
0 796 W 7370642 131072 zpool-abyss <none>
0 796 W 7370898 131072 zpool-abyss <none>
0 796 W 7371154 131072 zpool-abyss <none>
0 796 W 7371410 131072 zpool-abyss <none>
0 796 W 7371666 131072 zpool-abyss <none>
0 796 W 7371922 131072 zpool-abyss <none>
0 796 W 7372178 131072 zpool-abyss <none>
0 796 W 7372434 131072 zpool-abyss <none>
0 796 W 7372690 131072 zpool-abyss <none>
0 796 W 7372946 131072 zpool-abyss <none>
0 796 W 7373202 131072 zpool-abyss <none>
0 796 W 32514581 1024 zpool-abyss <none>
0 796 W 32514585 1024 zpool-abyss <none>
0 796 W 32514591 1024 zpool-abyss <none>
0 796 W 32514616 4096 zpool-abyss <none>
0 796 W 32514631 1024 zpool-abyss <none>
0 796 W 32514639 9728 zpool-abyss <none>
0 796 W 7348638 512 zpool-abyss <none>
0 796 W 7348639 512 zpool-abyss <none>
0 796 W 32514659 512 zpool-abyss <none>
0 796 W 32514658 512 zpool-abyss <none>
0 796 W 7348640 512 zpool-abyss <none>
0 796 W 32514660 512 zpool-abyss <none>
0 796 W 7348649 512 zpool-abyss <none>
0 796 W 32514669 512 zpool-abyss <none>
0 796 W 58728609 512 zpool-abyss <none>
0 796 W 7348643 3072 zpool-abyss <none>
0 796 W 7348641 1024 zpool-abyss <none>
0 796 W 32514661 4096 zpool-abyss <none>
0 796 W 58728616 1024 zpool-abyss <none>
0 796 W 58728622 3072 zpool-abyss <none>
0 0 R 7352192 65536 sched <none>
0 0 R 11557632 65536 sched <none>
0 796 W 7348654 1024 zpool-abyss <none>
0 796 W 32514674 1024 zpool-abyss <none>
0 796 W 7348658 1024 zpool-abyss <none>
0 796 W 58728628 1024 zpool-abyss <none>
0 796 W 7348643 5632 zpool-abyss <none>
0 796 W 7348660 8704 zpool-abyss <none>
0 796 W 32514663 5632 zpool-abyss <none>
0 796 W 32514676 1024 zpool-abyss <none>
0 796 W 32514680 8704 zpool-abyss <none>
0 796 W 58728609 512 zpool-abyss <none>
0 796 W 58728622 3072 zpool-abyss <none>
0 796 W 58728634 4096 zpool-abyss <none>
0 796 W 58728671 3584 zpool-abyss <none>
0 796 W 58728737 4096 zpool-abyss <none>
0 796 W 7348660 1024 zpool-abyss <none>
0 796 W 7348641 1024 zpool-abyss <none>
0 796 W 32514661 1024 zpool-abyss <none>
0 796 W 32514680 1024 zpool-abyss <none>
0 796 W 7348643 3584 zpool-abyss <none>
0 796 W 7348664 6656 zpool-abyss <none>
0 796 W 32514663 3584 zpool-abyss <none>
0 796 W 32514684 6656 zpool-abyss <none>
0 796 W 58728609 512 zpool-abyss <none>
0 796 W 58728616 1024 zpool-abyss <none>
0 796 W 58728622 3072 zpool-abyss <none>
0 796 W 58728636 1024 zpool-abyss <none>
0 796 W 58728640 1024 zpool-abyss <none>
0 796 W 58728671 3584 zpool-abyss <none>
0 796 W 58728741 2048 zpool-abyss <none>
0 796 W 260 1024 zpool-abyss <none>
0 796 W 772 1024 zpool-abyss <none>
0 796 W 156230404 1024 zpool-abyss <none>
0 796 W 156230916 1024 zpool-abyss <none>


Here's the mv:
./iosnoop
UID PID D BLOCK SIZE COMM PATHNAME
0 796 W 7348677 512 zpool-abyss <none>
0 796 W 32514697 512 zpool-abyss <none>
0 796 W 7348686 2048 zpool-abyss <none>
0 796 W 32514706 2048 zpool-abyss <none>
0 796 W 7348678 1536 zpool-abyss <none>
0 796 W 32514698 1536 zpool-abyss <none>
0 796 W 7348704 512 zpool-abyss <none>
0 796 W 32514722 512 zpool-abyss <none>
0 796 W 7348700 1024 zpool-abyss <none>
0 796 W 32514720 1024 zpool-abyss <none>
0 796 W 7348681 2560 zpool-abyss <none>
0 796 W 7348690 5120 zpool-abyss <none>
0 796 W 32514701 2560 zpool-abyss <none>
0 796 W 32514710 5120 zpool-abyss <none>
0 796 W 7348705 512 zpool-abyss <none>
0 796 W 7348706 512 zpool-abyss <none>
0 796 W 32514726 512 zpool-abyss <none>
0 796 W 32514723 512 zpool-abyss <none>
0 796 W 7348707 512 zpool-abyss <none>
0 796 W 32514727 512 zpool-abyss <none>
0 796 W 7348716 512 zpool-abyss <none>
0 796 W 32514736 512 zpool-abyss <none>
0 796 W 58728689 512 zpool-abyss <none>
0 796 W 7348710 3072 zpool-abyss <none>
0 796 W 7348708 1024 zpool-abyss <none>
0 796 W 32514728 4096 zpool-abyss <none>
0 796 W 58728642 1024 zpool-abyss <none>
0 796 W 58728678 3072 zpool-abyss <none>
0 796 W 7348721 1536 zpool-abyss <none>
0 796 W 7348724 1024 zpool-abyss <none>
0 796 W 32514741 1536 zpool-abyss <none>
0 796 W 58728690 1536 zpool-abyss <none>
0 796 W 7348717 2048 zpool-abyss <none>
0 796 W 7348726 8192 zpool-abyss <none>
0 796 W 32514737 2048 zpool-abyss <none>
0 796 W 32514744 9216 zpool-abyss <none>
0 796 W 7348716 512 zpool-abyss <none>
0 796 W 7348710 3072 zpool-abyss <none>
0 796 W 32514730 3584 zpool-abyss <none>
0 796 W 58728678 3072 zpool-abyss <none>
0 796 W 58728689 512 zpool-abyss <none>
0 796 W 58728693 1024 zpool-abyss <none>
0 796 W 58728697 1024 zpool-abyss <none>
0 796 W 58728745 5632 zpool-abyss <none>
0 796 W 58728761 3584 zpool-abyss <none>
0 796 W 7348708 1024 zpool-abyss <none>
0 796 W 7348742 1024 zpool-abyss <none>
0 796 W 32514762 1024 zpool-abyss <none>
0 796 W 32514728 1024 zpool-abyss <none>
0 796 W 7348710 3072 zpool-abyss <none>
0 796 W 7348716 512 zpool-abyss <none>
0 796 W 7348729 6656 zpool-abyss <none>
0 796 W 32514730 3584 zpool-abyss <none>
0 796 W 32514749 6656 zpool-abyss <none>
0 796 W 58728642 1024 zpool-abyss <none>
0 796 W 58728678 3072 zpool-abyss <none>
0 796 W 58728689 512 zpool-abyss <none>
0 796 W 58728697 1024 zpool-abyss <none>
0 796 W 58728752 2048 zpool-abyss <none>
0 796 W 58728761 4608 zpool-abyss <none>
0 796 W 7348708 1024 zpool-abyss <none>
0 796 W 7348744 1536 zpool-abyss <none>
0 796 W 32514764 1536 zpool-abyss <none>
0 796 W 32514728 1024 zpool-abyss <none>
0 796 W 7348710 3584 zpool-abyss <none>
0 796 W 7348729 6656 zpool-abyss <none>
0 796 W 32514730 3584 zpool-abyss <none>
0 796 W 32514749 6656 zpool-abyss <none>
0 796 W 58728642 1024 zpool-abyss <none>
0 796 W 58728678 3072 zpool-abyss <none>
0 796 W 58728697 1024 zpool-abyss <none>
0 796 W 58728752 2048 zpool-abyss <none>
0 796 W 58728761 3584 zpool-abyss <none>
0 796 W 58728770 1536 zpool-abyss <none>
0 796 W 58728689 512 zpool-abyss <none>
0 796 W 7348224 16384 zpool-abyss <none>
0 796 W 7348531 4096 zpool-abyss <none>
0 796 W 32514415 4096 zpool-abyss <none>
0 796 W 32514135 16384 zpool-abyss <none>
0 796 W 7348266 16384 zpool-abyss <none>
0 796 W 7348747 2048 zpool-abyss <none>
0 796 W 7348755 24576 zpool-abyss <none>
0 796 W 32514767 10240 zpool-abyss <none>
0 796 W 32514808 32768 zpool-abyss <none>
0 796 W 58728473 8192 zpool-abyss <none>
0 796 W 58728492 4096 zpool-abyss <none>
0 796 W 58728779 2048 zpool-abyss <none>
0 796 W 58728808 16384 zpool-abyss <none>
0 796 W 58728974 16384 zpool-abyss <none>
0 796 W 58729260 16384 zpool-abyss <none>
0 796 W 7348224 16384 zpool-abyss <none>
0 796 W 7348531 4096 zpool-abyss <none>
0 796 W 32514415 4096 zpool-abyss <none>
0 796 W 32514135 16384 zpool-abyss <none>
0 796 W 7348266 16384 zpool-abyss <none>
0 796 W 7348747 2048 zpool-abyss <none>
0 796 W 7348755 24576 zpool-abyss <none>
0 796 W 32514767 10240 zpool-abyss <none>
0 796 W 32514808 32768 zpool-abyss <none>
0 796 W 58728473 8192 zpool-abyss <none>
0 796 W 58728492 4096 zpool-abyss <none>
0 796 W 58728779 2048 zpool-abyss <none>
0 796 W 58728808 16384 zpool-abyss <none>
0 796 W 58728974 16384 zpool-abyss <none>
0 796 W 58729260 16384 zpool-abyss <none>
0 796 W 386 1024 zpool-abyss <none>
0 796 W 898 1024 zpool-abyss <none>
0 796 W 156230530 1024 zpool-abyss <none>
0 796 W 156231042 1024 zpool-abyss <none>

[Manojav Sridhar]

is this the case when moving any data (within a dataset or pool) or data between two datasets?

If I understand correctly data moving between 2 distinct pools is essentially a COW. Since the global pool and a dataset in that pool are 2 distinct pools that probably makes it a COW.

[Andre Lue]

Yes, this seems the case when moving any data.

[Manojav Sridhar]

Also another trick i did was the following.

offlined a slow disk in the mirror.

then did the mv between pool/* to pool/dataset/.

then online-ed the slower disk which resilvered, this seemed to go much faster.