Hi Dave,
El 23/10/20 a las 22:28, Dave Hall escribió:
Eneko,
# ceph health detail
HEALTH_WARN BlueFS spillover detected on 7 OSD(s)
BLUEFS_SPILLOVER BlueFS spillover detected on 7 OSD(s)
osd.1 spilled over 648 MiB metadata from 'db' device (28 GiB used
of 124 GiB) to slow device
osd.3 spilled over 613 MiB metadata from 'db' device (28 GiB used
of 124 GiB) to slow device
osd.4 spilled over 485 MiB metadata from 'db' device (28 GiB used
of 124 GiB) to slow device
osd.10 spilled over 1008 MiB metadata from 'db' device (28 GiB
used of 124 GiB) to slow device
osd.17 spilled over 808 MiB metadata from 'db' device (28 GiB
used of 124 GiB) to slow device
osd.18 spilled over 2.5 GiB metadata from 'db' device (28 GiB
used of 124 GiB) to slow device
osd.20 spilled over 1.5 GiB metadata from 'db' device (28 GiB
used of 124 GiB) to slow device
nvme0n1 259:1 0 1.5T 0 disk
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--6dcbb748--13f5--45cb--9d49--6c78d6589a71
│ 253:1 0 124G 0 lvm
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--736a22a8--e4aa--4da9--b63b--295d8f5f2a3d
│ 253:3 0 124G 0 lvm
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--751c6623--9870--4123--b551--1fd7fc837341
│ 253:5 0 124G 0 lvm
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--2a376e8d--abb1--42af--a4bd--4ae8734d703e
│ 253:7 0 124G 0 lvm
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--54fbe282--9b29--422b--bdb2--d7ed730bc589
│ 253:9 0 124G 0 lvm
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--c1153cd2--2ec0--4e7f--a3d7--91dac92560ad
│ 253:11 0 124G 0 lvm
├─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--d613f4eb--6ddc--4dd5--a2b5--cb520b6ba922
│ 253:13 0 124G 0 lvm
└─ceph--block--dbs--a2b7a161--d4da--4b86--a191--37564008adca-osd--block--db--41f75c25--67db--46e8--a3fb--ddee9e7f7fc4
253:15 0 124G 0 lvm
So, this means that if you use 300GB WAL/DB partitions, your spillovers
will be over (Bluestore is only ysing 28GiB as you can see).
I don't know what is the performance penalty of current spillover, but
at least you know those 300GB will be of use :)
Cheers
Dave Hall
Binghamton University
kdhall@xxxxxxxxxxxxxx <mailto:kdhall@xxxxxxxxxxxxxx>
607-760-2328 (Cell)
607-777-4641 (Office)
On 10/23/2020 6:00 AM, Eneko Lacunza wrote:
Hi Dave,
El 22/10/20 a las 19:43, Dave Hall escribió:
El 22/10/20 a las 16:48, Dave Hall escribió:
(BTW, Nautilus 14.2.7 on Debian non-container.)
We're about to purchase more OSD nodes for our cluster, but I have
a couple questions about hardware choices. Our original nodes
were 8 x 12TB SAS drives and a 1.6TB Samsung NVMe card for WAL,
DB, etc.
We chose the NVMe card for performance since it has an 8 lane PCIe
interface. However, we're currently BlueFS spillovers.
The Tyan chassis we are considering has the option of 4 x U.2 NVMe
bays - each with 4 PCIe lanes, (and 8 SAS bays). It has occurred
to me that I might stripe 4 1TB NVMe drives together to get much
more space for WAL/DB and a net performance of 16 PCIe lanes.
Any thoughts on this approach?
Don't stripe them, if one NVMe fails you'll lose all OSDs. Just use
1 NVMe drive for 2 SAS drives and provision 300GB for WAL/DB for
each OSD (see related threads on this mailing list about why that
exact size).
This way if a NVMe fails, you'll only lose 2 OSD.
I was under the impression that everything that BlueStore puts on
the SSD/NVMe could be reconstructed from information on the OSD. Am
I mistaken about this? If so, my single 1.6TB NVMe card is equally
vulnerable.
I don't think so, that info only exists on that partition as was the
case with filestore journal. Your single 1.6TB NVMe is vulnerable, yes.
Also, what size of WAL/DB partitions do you have now, and what
spillover size?
I recently posted another question to the list on this topic, since
I now have spillover on 7 of 24 OSDs. Since the data layout on the
NVMe for BlueStore is not traditional I've never quite figured out
how to get this information. The current partition size is 1.6TB
/12 since we had the possibility to add for more drives to each
node. How that was divided between WAL, DB, etc. is something I'd
like to be able to understand. However, we're not going to add the
extra 4 drives, so expanding the LVM partitions is now a possibility.
Can you paste the warning message? If shows the spillover size. What
size are the partitions on NVMe disk (lsblk)
Cheers
--
Eneko Lacunza | +34 943 569 206
| elacunza@xxxxxxxxx
Zuzendari teknikoa | https://www.binovo.es
Director técnico | Astigarragako Bidea, 2 - 2º izda.
BINOVO IT HUMAN PROJECT S.L | oficina 10-11, 20180 Oiartzun
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