Lindsay Mathieson
2014-12-30 14:13:28 UTC
I looked at the section for setting up different pools with different OSD's (e.g SSD Pool):
http://ceph.com/docs/master/rados/operations/crush-map/#placing-different-pools-on-different-osds
And it seems to make the assumption that the ssd's and platters all live on separate hosts.
Not the case at all for my setup and I imagine for most people I have ssd's mixed with
platters on the same hosts.
In that case should one have the root buckets referencing buckets not based on hosts, e.g,
something like this:
# devices
# Platters
device 0 osd.0
device 1 osd.1
# SSD
device 2 osd.2
device 3 osd.3
host vnb {
id -2 # do not change unnecessarily
# weight 1.000
alg straw
hash 0 # rjenkins1
item osd.0 weight 1.000
item osd.2 weight 1.000
}
host vng {
id -3 # do not change unnecessarily
# weight 1.000
alg straw
hash 0 # rjenkins1
item osd.1 weight 1.000
item osd.3 weight 1.000
}
row disk-platter {
alg straw
hash 0 # rjenkins1
item osd.0 weight 1.000
item osd.1 weight 1.000
}
row disk-ssd {
alg straw
hash 0 # rjenkins1
item osd.2 weight 1.000
item osd.3 weight 1.000
}
root default {
id -1 # do not change unnecessarily
# weight 2.000
alg straw
hash 0 # rjenkins1
item disk-platter weight 2.000
}
root ssd {
id -4
alg straw
hash 0
item disk-ssd weight 2.000
}
# rules
rule replicated_ruleset {
ruleset 0
type replicated
min_size 1
max_size 10
step take default
step chooseleaf firstn 0 type host
step emit
}
rule ssd {
ruleset 1
type replicated
min_size 0
max_size 4
step take ssd
step chooseleaf firstn 0 type host
step emit
}
http://ceph.com/docs/master/rados/operations/crush-map/#placing-different-pools-on-different-osds
And it seems to make the assumption that the ssd's and platters all live on separate hosts.
Not the case at all for my setup and I imagine for most people I have ssd's mixed with
platters on the same hosts.
In that case should one have the root buckets referencing buckets not based on hosts, e.g,
something like this:
# devices
# Platters
device 0 osd.0
device 1 osd.1
# SSD
device 2 osd.2
device 3 osd.3
host vnb {
id -2 # do not change unnecessarily
# weight 1.000
alg straw
hash 0 # rjenkins1
item osd.0 weight 1.000
item osd.2 weight 1.000
}
host vng {
id -3 # do not change unnecessarily
# weight 1.000
alg straw
hash 0 # rjenkins1
item osd.1 weight 1.000
item osd.3 weight 1.000
}
row disk-platter {
alg straw
hash 0 # rjenkins1
item osd.0 weight 1.000
item osd.1 weight 1.000
}
row disk-ssd {
alg straw
hash 0 # rjenkins1
item osd.2 weight 1.000
item osd.3 weight 1.000
}
root default {
id -1 # do not change unnecessarily
# weight 2.000
alg straw
hash 0 # rjenkins1
item disk-platter weight 2.000
}
root ssd {
id -4
alg straw
hash 0
item disk-ssd weight 2.000
}
# rules
rule replicated_ruleset {
ruleset 0
type replicated
min_size 1
max_size 10
step take default
step chooseleaf firstn 0 type host
step emit
}
rule ssd {
ruleset 1
type replicated
min_size 0
max_size 4
step take ssd
step chooseleaf firstn 0 type host
step emit
}
--
Lindsay
Lindsay