On 4/1/20 12:05 AM, Zygo Blaxell wrote:
On Tue, Mar 31, 2020 at 10:46:17PM +0100, Graham Cobb wrote:
On 31/03/2020 20:10, Goffredo Baroncelli wrote:
WARNING: ------------------------------------------------------
WARNING: Detection of multiple profiles for a block group type:
WARNING:
WARNING: * DATA -> [raid1c3, single]
WARNING: * METADATA -> [raid1, single]
WARNING:
WARNING: Please consider using 'btrfs balance ...' commands set
WARNING: to solve this issue.
WARNING: ------------------------------------------------------
The check is a good a idea but I think the warning is too strong. I
would prefer that the word "Warning" is reserved for cases and
operations that may actually damage data (such as reformating a
filesystem). [Note: in a previous job, my employer decided that the word
Warning was ONLY to be used if there was a risk of harm to a human - for
example, electrical safety]
In some fields, like medical devices, terms "warning", "caution", "notice"
are strictly regulated; and your employer is right: warning is
required only when an human harm could happen.
In btrfs however, the rules are a bit relaxed; so we have only ERROR (fatal)
and Warning (which is more like caution).
However I think that an unexpected profile is to be considered a severe fault.
I.e. you could have a RAID5 instead of a RAID1, where the former is more
fragile than the latter.
Moreover I suspect that a lot of problems reported on mailing list born from
a mixed profile filesystem...
Also, btrfs fi usage is something that I routinely run continuously in a
window (using watch) when a remove/replace/balance operation is in
I was going to say please put all the new output lines at the bottom,
The added lines are the last ones. Do you mean top ?
so that 'watch' windows can be minimally sized without having to write
something like
watch 'btrfs fi usage /foo | sed -e "g/WARNING:/d"'
People with short terminal windows running btrfs fi usage directly from
the command line would probably complain about extra lines at the bottom...
Another good idea here would be a --quiet switch, or
'--no-profile-warning'.
I think that having a global switch like '--no-profile-warning' is a good thing.
progress to monitor at a glance what is happening - I don't want to
waste all that space on the screen. To say nothing of the annoyance of
having it shouting at me for weeks on end while **I AM TRYING TO FIX THE
DAMN PROBLEM!**.
I would suggest a more compact layout and factual tone. Something like:
Caution: This filesystem has multiple profiles for a block group type
so new block groups will have unpredictable profiles.
* DATA -> [raid1c3, single]
* METADATA -> [raid1, single]
Use of 'btrfs balance' is recommended as soon as possible to move all
blocks to a single profile for each of data and metadata.
How about a one-liner:
NOTE: Multiple profiles detected. See 'man btrfs-filesystem'.
WARNING: Multiple profiles detected. See 'man btrfs-filesystem'.
WARNING: data -> [raid1c3, single], metadata -> [raid1, single]
I think that the one above could be a good compromise.
I am thinking also to combine '--no-profile-warning' and '--verbose' to have
three different warning level (--no-profile-warning -> no warning at all, nothing
-> small warning, --verbose -> "giant" warning).
However the Anand's patches set for a global --verbose is still pending.
Also these global switches can be sets in an environment variables (like BTRFS_GLOBAL_OPTIONS).
with a section in the btrfs-filesystem man page giving a detailed
description of the problem and examples of possible remedies.
I will try, however my English is terrific....
BR
G.Baroncelli
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