Hi,
I read your first email again and noticed that ceph-volume already
identifies the drives sdr and sds as non-rotational and as available.
That would also explain the empty rejected_reasons field because they
are not rejected at (this stage?). Where do you read that information
that one SSD is identified as rotational?
The next thing I'm wondering about is the ratio, if I counted
correctly you try to fit 22 DBs into one SSD with 186 GB size which
would make one DB only about 8 GB. What is your use case for this
cluster? For RBD this small DB might be enough but for S3 this most
likely won't be enough, depending on the actual workload of course.
And why do you want to split WAL and DB anyway if both SSDs are
identical? You would only benefit from a separate WAL device if that
is faster than the DB device. This doesn't solve the mentioned
problem, of course, but it doesn't really make sense. I would
recommend to use both SSDs for both WAL and DB, this would improve
your ratio (11 OSDs per SSD) and also reduce the impact of a failing
SSD (22 drives vs. 11 drives if one SSD fails).
Regards,
Eugen
Zitat von Chris <hagfelsh@xxxxxxxxx>:
Awesome! I had no idea that's where this was pulling it from! However...
Both of the SSDs do have rotational set to 0 :(
root@ceph05:/sys/block# cat sd{r,s}/queue/rotational
I found a line in cephadm.log that also agrees; this one is from docker:
"sys_api": {
"removable": "0",
"ro": "0",
"vendor": "HITACHI",
"model": "HUSSL4020BSS600",
"rev": "A120",
"sas_address": "0x5000cca0132441de",
"sas_device_handle": "0x0021",
"support_discard": "0",
"rotational": "0",
"nr_requests": "256",
"scheduler_mode": "mq-deadline",
"partitions": {},
"sectors": 0,
"sectorsize": "512",
"size": 200049647616.0,
"human_readable_size": "186.31 GB",
"path": "/dev/sdr",
"locked": 0
},
lsscsi -twigs output:
[4:0:15:0] disk sas:0x5000cca0132441de 0
/dev/sdr SHITACHI_HUSSL4020BSS600_XTVMY4KA /dev/sg19
200GB
[4:0:16:0] disk sas:0x5000cca013243b96 0
/dev/sds SHITACHI_HUSSL4020BSS600_XTVMXRLA /dev/sg20
200GB
This is interesting, too. Just a bit down in the docker line in cephadm,
there's an empty array for rejected reasons:
"available": true,
"rejected_reasons": [],
"device_id": "HUSSL4020BSS600_5000cca0132441dc",
"lvs": []
I wonder what's causing this! Surely there's a reason hiding in here
somewhere.
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