Invalid/wrong statistics during migration

[ermanishchawla]

While migrating a VM from one node to another, the statistics are shown, which are wrong, please check attachment

 

[ermanishchawla]

2022-09-05 08:07:51 migration active, transferred 146.3 GiB of 96.1 GiB VM-state, 412.7 MiB/s
2022-09-05 08:07:52 migration active, transferred 146.7 GiB of 96.1 GiB VM-state, 335.0 MiB/s
2022-09-05 08:07:53 migration active, transferred 147.0 GiB of 96.1 GiB VM-state, 315.0 MiB/s
2022-09-05 08:07:54 migration active, transferred 147.2 GiB of 96.1 GiB VM-state, 274.3 MiB/s
2022-09-05 08:07:55 migration active, transferred 147.5 GiB of 96.1 GiB VM-state, 322.2 MiB/s
2022-09-05 08:07:56 migration active, transferred 147.8 GiB of 96.1 GiB VM-state, 305.9 MiB/s
2022-09-05 08:07:58 migration active, transferred 148.1 GiB of 96.1 GiB VM-state, 303.5 MiB/s
2022-09-05 08:07:59 migration active, transferred 148.4 GiB of 96.1 GiB VM-state, 218.2 MiB/s
2022-09-05 08:08:00 migration active, transferred 148.7 GiB of 96.1 GiB VM-state, 387.1 MiB/s
2022-09-05 08:08:01 migration active, transferred 149.0 GiB of 96.1 GiB VM-state, 366.6 MiB/s
2022-09-05 08:08:02 migration active, transferred 149.3 GiB of 96.1 GiB VM-state, 354.4 MiB/s
2022-09-05 08:08:03 migration active, transferred 149.7 GiB of 96.1 GiB VM-state, 278.9 MiB/s
2022-09-05 08:08:04 migration active, transferred 150.0 GiB of 96.1 GiB VM-state, 352.0 MiB/s
2022-09-05 08:08:05 migration active, transferred 150.3 GiB of 96.1 GiB VM-state, 371.4 MiB/s
2022-09-05 08:08:06 migration active, transferred 150.6 GiB of 96.1 GiB VM-state, 252.5 MiB/s
2022-09-05 08:08:07 migration active, transferred 150.9 GiB of 96.1 GiB VM-state, 667.0 MiB/s
2022-09-05 08:08:07 xbzrle: send updates to 27083 pages in 44.9 MiB encoded memory, cache-miss 99.51%, overflow 3941
2022-09-05 08:08:08 migration active, transferred 151.2 GiB of 96.1 GiB VM-state, 493.6 MiB/s
2022-09-05 08:08:08 xbzrle: send updates to 83174 pages in 245.6 MiB encoded memory, cache-miss 99.51%, overflow 52278
2022-09-05 08:08:09 migration active, transferred 151.6 GiB of 96.1 GiB VM-state, 682.3 MiB/s
2022-09-05 08:08:09 xbzrle: send updates to 146355 pages in 447.0 MiB encoded memory, cache-miss 99.51%, overflow 101722
2022-09-05 08:08:10 migration active, transferred 151.9 GiB of 96.1 GiB VM-state, 436.6 MiB/s
2022-09-05 08:08:10 xbzrle: send updates to 212929 pages in 538.9 MiB encoded memory, cache-miss 99.51%, overflow 123243
2022-09-05 08:08:11 migration active, transferred 152.2 GiB of 96.1 GiB VM-state, 202.6 MiB/s
2022-09-05 08:08:11 xbzrle: send updates to 229068 pages in 545.3 MiB encoded memory, cache-miss 99.51%, overflow 123725
2022-09-05 08:08:12 migration active, transferred 152.3 GiB of 96.1 GiB VM-state, 335.8 MiB/s
2022-09-05 08:08:12 xbzrle: send updates to 239137 pages in 549.9 MiB encoded memory, cache-miss 99.51%, overflow 124255
2022-09-05 08:08:13 migration active, transferred 152.4 GiB of 96.1 GiB VM-state, 66.6 MiB/s, VM dirties lots of memory: 73.8 MiB/s
2022-09-05 08:08:13 xbzrle: send updates to 246363 pages in 552.4 MiB encoded memory, cache-miss 99.51%, overflow 124404
2022-09-05 08:08:14 migration active, transferred 152.7 GiB of 96.1 GiB VM-state, 308.6 MiB/s
2022-09-05 08:08:14 xbzrle: send updates to 250262 pages in 553.8 MiB encoded memory, cache-miss 99.51%, overflow 124458
2022-09-05 08:08:15 migration active, transferred 152.9 GiB of 96.1 GiB VM-state, 190.0 MiB/s
2022-09-05 08:08:15 xbzrle: send updates to 250794 pages in 554.6 MiB encoded memory, cache-miss 99.51%, overflow 124479
2022-09-05 08:08:16 migration active, transferred 153.2 GiB of 96.1 GiB VM-state, 448.8 MiB/s
2022-09-05 08:08:16 xbzrle: send updates to 265066 pages in 555.9 MiB encoded memory, cache-miss 99.51%, overflow 124687
2022-09-05 08:08:17 migration active, transferred 153.5 GiB of 96.1 GiB VM-state, 334.0 MiB/s
2022-09-05 08:08:17 xbzrle: send updates to 273162 pages in 561.3 MiB encoded memory, cache-miss 99.51%, overflow 126027
2022-09-05 08:08:18 migration active, transferred 153.8 GiB of 96.1 GiB VM-state, 316.9 MiB/s
2022-09-05 08:08:18 xbzrle: send updates to 282225 pages in 565.0 MiB encoded memory, cache-miss 99.51%, overflow 126948
2022-09-05 08:08:19 migration active, transferred 154.1 GiB of 96.1 GiB VM-state, 325.0 MiB/s
2022-09-05 08:08:19 xbzrle: send updates to 290046 pages in 569.8 MiB encoded memory, cache-miss 99.51%, overflow 128124
2022-09-05 08:08:20 migration active, transferred 154.5 GiB of 96.1 GiB VM-state, 428.2 MiB/s
2022-09-05 08:08:20 xbzrle: send updates to 299562 pages in 575.0 MiB encoded memory, cache-miss 99.51%, overflow 129409
2022-09-05 08:08:21 migration active, transferred 154.9 GiB of 96.1 GiB VM-state, 434.9 MiB/s
2022-09-05 08:08:21 xbzrle: send updates to 309124 pages in 579.8 MiB encoded memory, cache-miss 99.51%, overflow 130572
2022-09-05 08:08:22 migration active, transferred 155.2 GiB of 96.1 GiB VM-state, 420.2 MiB/s

 

[shrdlicka]

Hi,

looks like you are doing a live migration. From the log, it seems like your VM is very busy. It tries to transfer the data but you RAM gets filled faster than the transfer rate so it can't catch up with transferring the data.

 

[ermanishchawla]

I know the reason, why it is happening, I am only asking why it is showing wrong
transferred 147.2 GiB of 96.1 GiB VM-state, 274.3 MiB/s
147 out 96 is not possible

 

[fabian]

it's not showing anything "wrong" - the first number is how much was transferred, the second is the total size of the state. since migration needs to converge, the transferred number can be (a lot) higher than the total size number.

 

[ermanishchawla]

it's not showing anything "wrong" - the first number is how much was transferred, the second is the total size of the state. since migration needs to converge, the transferred number can be (a lot) higher than the total size number.

If that is the case, the word "of" in the sentence is misleading
147Gb of 97Gb
Stating clearly is better I believe
Memory state is lagging, transfered:147GB, Actual Required: 96GB