Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Enhance Pool size calculation re new raid levels #2525 #2534

Merged
merged 1 commit into from
Apr 25, 2023
+131 −39
Merged

Enhance Pool size calculation re new raid levels #2525 #2534

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
170 changes: 131 additions & 39 deletions src/rockstor/fs/btrfs.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -98,7 +98,8 @@
BalanceStatusAll = collections.namedtuple("BalanceStatusAll", "active internal status")
# Named Tuple to define raid profile limits and data/metadata
btrfs_profile = collections.namedtuple(
"btrfs_profile", "min_dev_count max_dev_missing data_raid metadata_raid"
"btrfs_profile",
"min_dev_count max_dev_missing data_raid metadata_raid data_copies data_parity",
)
# List of Rockstor btrfs raid profiles indexed by their name.
# I.e. PROFILE[raid_level].min_dev_count
Expand All @@ -115,64 +116,154 @@
# We specify a min dev count of 4 to account for any raid level,
# and likewise play safe by allowing for no missing devices.
"unknown": btrfs_profile(
min_dev_count=4, max_dev_missing=0, data_raid="unknown", metadata_raid="unknown"
min_dev_count=4,
max_dev_missing=0,
data_raid="unknown",
metadata_raid="unknown",
data_copies=1,
data_parity=0,
),
# non redundant profiles!
"single": btrfs_profile(
min_dev_count=1, max_dev_missing=0, data_raid="single", metadata_raid="single"
min_dev_count=1,
max_dev_missing=0,
data_raid="single",
metadata_raid="single",
data_copies=1,
data_parity=0,
),
"single-dup": btrfs_profile(
min_dev_count=1, max_dev_missing=0, data_raid="single", metadata_raid="dup"
min_dev_count=1,
max_dev_missing=0,
data_raid="single",
metadata_raid="dup",
data_copies=1,
data_parity=0,
),
"raid0": btrfs_profile(
min_dev_count=2, max_dev_missing=0, data_raid="raid0", metadata_raid="raid0"
min_dev_count=2,
max_dev_missing=0,
data_raid="raid0",
metadata_raid="raid0",
data_copies=1,
data_parity=0,
),
# Mirrored profiles:
"raid1": btrfs_profile(
min_dev_count=2, max_dev_missing=1, data_raid="raid1", metadata_raid="raid1"
min_dev_count=2,
max_dev_missing=1,
data_raid="raid1",
metadata_raid="raid1",
data_copies=2,
data_parity=0,
),
"raid1c3": btrfs_profile(
min_dev_count=3, max_dev_missing=2, data_raid="raid1c3", metadata_raid="raid1c3"
min_dev_count=3,
max_dev_missing=2,
data_raid="raid1c3",
metadata_raid="raid1c3",
data_copies=3,
data_parity=0,
),
"raid1c4": btrfs_profile(
min_dev_count=4, max_dev_missing=3, data_raid="raid1c4", metadata_raid="raid1c4"
min_dev_count=4,
max_dev_missing=3,
data_raid="raid1c4",
metadata_raid="raid1c4",
data_copies=4,
data_parity=0,
),
"raid10": btrfs_profile(
min_dev_count=4, max_dev_missing=1, data_raid="raid10", metadata_raid="raid10"
min_dev_count=4,
max_dev_missing=1,
data_raid="raid10",
metadata_raid="raid10",
data_copies=2,
data_parity=0,
),
# Parity raid levels (recommended min_dev_count is 3 & 4 respectively)
"raid5": btrfs_profile(
min_dev_count=2, max_dev_missing=1, data_raid="raid5", metadata_raid="raid5"
min_dev_count=2,
max_dev_missing=1,
data_raid="raid5",
metadata_raid="raid5",
data_copies=1,
data_parity=1,
),
"raid6": btrfs_profile(
min_dev_count=3, max_dev_missing=2, data_raid="raid6", metadata_raid="raid6"
min_dev_count=3,
max_dev_missing=2,
data_raid="raid6",
metadata_raid="raid6",
data_copies=1,
data_parity=2,
),
# ------- MIXED PROFILES DATA-METADATA (max 10 chars) -------
# Mixed Mirrored profiles:
"raid1-1c3": btrfs_profile(
min_dev_count=3, max_dev_missing=1, data_raid="raid1", metadata_raid="raid1c3"
min_dev_count=3,
max_dev_missing=1,
data_raid="raid1",
metadata_raid="raid1c3",
data_copies=2,
data_parity=0,
),
"raid1-1c4": btrfs_profile(
min_dev_count=4, max_dev_missing=1, data_raid="raid1", metadata_raid="raid1c4"
min_dev_count=4,
max_dev_missing=1,
data_raid="raid1",
metadata_raid="raid1c4",
data_copies=2,
data_parity=0,
),
"raid10-1c3": btrfs_profile(
min_dev_count=4, max_dev_missing=1, data_raid="raid10", metadata_raid="raid1c3"
min_dev_count=4,
max_dev_missing=1,
data_raid="raid10",
metadata_raid="raid1c3",
data_copies=2,
data_parity=0,
),
"raid10-1c4": btrfs_profile(
min_dev_count=4, max_dev_missing=1, data_raid="raid10", metadata_raid="raid1c4"
min_dev_count=4,
max_dev_missing=1,
data_raid="raid10",
metadata_raid="raid1c4",
data_copies=2,
data_parity=0,
),
# Parity data - Mirrored metadata
"raid5-1": btrfs_profile(
min_dev_count=2, max_dev_missing=1, data_raid="raid5", metadata_raid="raid1"
min_dev_count=2,
max_dev_missing=1,
data_raid="raid5",
metadata_raid="raid1",
data_copies=1,
data_parity=1,
),
"raid5-1c3": btrfs_profile(
min_dev_count=3, max_dev_missing=1, data_raid="raid5", metadata_raid="raid1c3"
min_dev_count=3,
max_dev_missing=1,
data_raid="raid5",
metadata_raid="raid1c3",
data_copies=1,
data_parity=1,
),
"raid6-1c3": btrfs_profile(
min_dev_count=3, max_dev_missing=2, data_raid="raid6", metadata_raid="raid1c3"
min_dev_count=3,
max_dev_missing=2,
data_raid="raid6",
metadata_raid="raid1c3",
data_copies=1,
data_parity=2,
),
"raid6-1c4": btrfs_profile(
min_dev_count=4, max_dev_missing=2, data_raid="raid6", metadata_raid="raid1c4"
min_dev_count=4,
max_dev_missing=2,
data_raid="raid6",
metadata_raid="raid1c4",
data_copies=1,
data_parity=2,
),
}

Expand Down Expand Up @@ -1713,38 +1804,39 @@ def usage_bound(disk_sizes, num_devices, raid_level):
"""Return the total amount of storage possible within this pool's set
of disks, in bytes.

Algorithm adapted from Hugo Mills' implementation at:
Algorithm adapted from Hugo Mills' implementation previously at:
http://carfax.org.uk/btrfs-usage/js/btrfs-usage.js
and replaced by the elm generated: https://carfax.org.uk/btrfs-usage/elm.js
"""
# Determine RAID parameters
data_ratio = 1
stripes = 1
parity = 0
data_copies = PROFILE[raid_level].data_copies
data_parity = PROFILE[raid_level].data_parity

# TODO: As stripes/chunks depend on pool geometry we cannot use PROFILE.
# Once we are Python 3 compatible, re-assess our size calculation in light of
# https://github.com/knorrie/python-btrfs i.e.:
# btrfs-space-calculator
stripes = 1
# Number of chunks to write at a time: as many as possible within the
# number of stripes
chunks = num_devices

if raid_level == "single":
if raid_level.startswith(("unknown", "single")):
chunks = 1
elif raid_level == "raid0":
# We have no mixed raid levels with raid0, but in case we encounter them:
elif raid_level.startswith("raid0"):
stripes = 2
elif raid_level == "raid1":
data_ratio = 2
# Take care not to match raid10 before its time:
elif raid_level == "raid1" or raid_level.startswith("raid1-"):
chunks = 2
elif raid_level == "raid10":
data_ratio = 2
elif raid_level.startswith("raid10"):
stripes = max(2, int(num_devices / 2))
elif raid_level == "raid5":
parity = 1
elif raid_level == "raid6":
parity = 2

# Round down so that we have an exact number of duplicate copies
chunks -= chunks % data_ratio
chunks -= chunks % data_copies

# Check for feasibility at the lower end
if num_devices < data_ratio * (stripes + parity):
if num_devices < data_copies * (stripes + data_parity):
return 0

# Compute the trivial bound
Expand All @@ -1754,8 +1846,8 @@ def usage_bound(disk_sizes, num_devices, raid_level):
# modify the trivial bound if it passes.
bounding_q = -1
for q in range(chunks - 1):
slice = sum(disk_sizes[q + 1 :])
b = int(slice / (chunks - q - 1))
slice_value = sum(disk_sizes[q + 1 :])
b = int(slice_value / (chunks - q - 1))
if disk_sizes[q] >= b and b < bound:
bound = b
bounding_q = q
Expand All @@ -1764,7 +1856,7 @@ def usage_bound(disk_sizes, num_devices, raid_level):
# have no bounding_q, then we have hit the trivial bound, and exhausted
# all space, so we can return immediately.
if bounding_q == -1:
return bound * ((chunks / data_ratio) - parity)
return bound * ((chunks / data_copies) - data_parity)

# If we have a bounding_q, then all the devices past q are full, and
# we can remove them. The devices up to q have been used in every one
Expand All @@ -1775,7 +1867,7 @@ def usage_bound(disk_sizes, num_devices, raid_level):

new_bound = usage_bound(disk_sizes, bounding_q + 1, raid_level)

return bound * ((chunks / data_ratio) - parity) + new_bound
return bound * ((chunks / data_copies) - data_parity) + new_bound


def scrub_start(pool, force=False):
Expand Down