Hi all,
This is the 4th attempt of my patches related to show how the data
are stored in a btrfs filesystem. I rebased all the patches on the v3.13
btrfs-progs.
These patches update the btrfs fi df command and add two new commands:
- btrfs filesystem disk-usage <path>
- btrfs device disk-usage <path>
The command "btrfs filesystem df" now shows only the disk
usage/available.
$ sudo btrfs filesystem df /mnt/btrfs1/
Disk size: 400.00GB
Disk allocated: 8.04GB
Disk unallocated: 391.97GB
Used: 11.29MB
Free (Estimated): 250.45GB (Max: 396.99GB, min: 201.00GB)
Data to disk ratio: 63 %
The "Free (Estimated)" tries to give an estimation of the free space
on the basis of the chunks usage. Max and min are the maximum allowable
space (if the next chunk are allocated as SINGLE) or the minimum one (
if the next chunks are allocated as DUP/RAID1/RAID10).
The other two commands show the chunks in the disks.
$ sudo btrfs filesystem disk-usage /mnt/btrfs1/
Data,Single: Size:8.00MB, Used:0.00
/dev/vdb 8.00MB
Data,RAID6: Size:2.00GB, Used:11.25MB
/dev/vdb 1.00GB
/dev/vdc 1.00GB
/dev/vdd 1.00GB
/dev/vde 1.00GB
Metadata,Single: Size:8.00MB, Used:0.00
/dev/vdb 8.00MB
Metadata,RAID5: Size:3.00GB, Used:36.00KB
/dev/vdb 1.00GB
/dev/vdc 1.00GB
/dev/vdd 1.00GB
/dev/vde 1.00GB
System,Single: Size:4.00MB, Used:0.00
/dev/vdb 4.00MB
System,RAID5: Size:12.00MB, Used:4.00KB
/dev/vdb 4.00MB
/dev/vdc 4.00MB
/dev/vdd 4.00MB
/dev/vde 4.00MB
Unallocated:
/dev/vdb 97.98GB
/dev/vdc 98.00GB
/dev/vdd 98.00GB
/dev/vde 98.00GB
or in tabular format
$ sudo ./btrfs filesystem disk-usage -t /mnt/btrfs1/
Data Data Metadata Metadata System System
Single RAID6 Single RAID5 Single RAID5 Unallocated
/dev/vdb 8.00MB 1.00GB 8.00MB 1.00GB 4.00MB 4.00MB 97.98GB
/dev/vdc - 1.00GB - 1.00GB - 4.00MB 98.00GB
/dev/vdd - 1.00GB - 1.00GB - 4.00MB 98.00GB
/dev/vde - 1.00GB - 1.00GB - 4.00MB 98.00GB
====== ======= ======== ======== ====== ======= ==========Total
8.00MB 2.00GB 8.00MB 3.00GB 4.00MB 12.00MB 391.97GB
Used 0.00 11.25MB 0.00 36.00KB 0.00 4.00KB
These are the most complete output, where it is possible to know which
disk a chunk uses and the usage of every chunk.
Finally the last command shows which chunks a disk hosts:
$ sudo ./btrfs device disk-usage /mnt/btrfs1/
/dev/vdb 100.00GB
Data,Single: 8.00MB
Data,RAID6: 1.00GB
Metadata,Single: 8.00MB
Metadata,RAID5: 1.00GB
System,Single: 4.00MB
System,RAID5: 4.00MB
Unallocated: 97.98GB
/dev/vdc 100.00GB
Data,RAID6: 1.00GB
Metadata,RAID5: 1.00GB
System,RAID5: 4.00MB
Unallocated: 98.00GB
/dev/vdd 100.00GB
Data,RAID6: 1.00GB
Metadata,RAID5: 1.00GB
System,RAID5: 4.00MB
Unallocated: 98.00GB
/dev/vde 100.00GB
Data,RAID6: 1.00GB
Metadata,RAID5: 1.00GB
System,RAID5: 4.00MB
Unallocated: 98.00GB
More or less are the same information above, only grouped by disk.
Unfortunately I don't have any information about the chunk usage per disk
basis.
Comments are welcome.
The code is pullable from
https://github.com/kreijack/btrfs-progs.git
branch
dfdu
Finally I have to point out that the command btrfs fi df previous didn't
require
the root capability, now with my patches it is required, because I need
to know some info about the chunks so I need to use the
"BTRFS_IOC_TREE_SEARCH".
I think that there are the following possibilities:
1) accept this regresssion
2) remove the command "btrfs fi df" and leave only "btrfs fi
disk-usage" and
"btrfs dev disk-usage"
3) adding a new ioctl which could be used without root capability. Of course
this ioctl would return only a subset of the BTRFS_IOC_TREE_SEARCH info
I think that the 3) would be the "long term" solution. I am not happy
about
the 1), so as "short term solution" I think that we should go with the
2).
What do you think ?
Below the description of the patches.
--
BR
G.Baroncelli
Changelog:
v1 2013/02/18 First issue
v2 2013/02/23 Fix uncorrct "not enough memory" handling in patch #1.
Thanks to Zac to highlight it.
v3 2013/03/10 - Rebased on the latest mason git repository
- Small fix in the comment
- Increase the buffer in the function df_pretty_sizes() to
avoid buffer pverwflow (thanks to Zach to highlight it)
- adding the sla_pretty_sizes() function to remove the call
of string_list_add() from df_pretty_sizes.
v4 2014/02/13 - Rebased to v3.12
- Replace MB/GB/TB with MiB/GiB/TiB
- correct some small bug related to mixing same raid level
with different disk number
-removing the string_list_add() function
--
gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
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