13.07.2016 09:04, Pranith Kumar Karampuri пишет:
On Wed, Jul 13, 2016 at 10:29 AM, Dmitry Melekhov <[email protected]
<mailto:[email protected]>> wrote:
13.07.2016 08:56, Pranith Kumar Karampuri пишет:
On Wed, Jul 13, 2016 at 10:23 AM, Dmitry Melekhov <[email protected]
<mailto:[email protected]>> wrote:
13.07.2016 08:46, Pranith Kumar Karampuri пишет:
On Wed, Jul 13, 2016 at 10:10 AM, Dmitry Melekhov
<[email protected] <mailto:[email protected]>> wrote:
13.07.2016 08:36, Pranith Kumar Karampuri пишет:
On Wed, Jul 13, 2016 at 9:35 AM, Dmitry Melekhov
<[email protected] <mailto:[email protected]>> wrote:
13.07.2016 01:52, Anuradha Talur пишет:
----- Original Message -----
From: "Dmitry Melekhov" <[email protected]
<mailto:[email protected]>>
To: "Pranith Kumar Karampuri"
<[email protected]
<mailto:[email protected]>>
Cc: "gluster-users"
<[email protected]
<mailto:[email protected]>>
Sent: Tuesday, July 12, 2016 9:27:17 PM
Subject: Re: [Gluster-users] 3.7.13, index
healing broken?
12.07.2016 17:39, Pranith Kumar Karampuri
пишет:
Wow, what are the steps to recreate the
problem?
just set file length to zero, always
reproducible.
If you are setting the file length to 0 on one
of the bricks (looks like
that is the case), it is not a bug.
Index heal relies on failures seen from the
mount point(s)
to identify the files that need heal. It won't
be able to recognize any file
modification done directly on bricks. Same goes
for heal info command which
is the reason heal info also shows 0 entries.
Well, this makes self-heal useless then- if any
file is accidently corrupted or deleted (yes! if
file is deleted directly from brick this is no
recognized by idex heal too), then it will not be
self-healed, because self-heal uses index heal.
It is better to look into bit-rot feature if you want
to guard against these kinds of problems.
Bit rot detects bit problems, not missing files or their
wrong length, i.e. this is overhead for such simple task.
It detects wrong length. Because checksum won't match anymore.
Yes, sure. I guess that it will detect missed files too. But
it needs far more resources, then just comparing directories
in bricks?
What use-case you are trying out is leading to changing
things directly on the brick?
I'm trying to test gluster failure tolerance and right now
I'm not happy with it...
Which cases of fault tolerance are you not happy with? Making
changes directly on the brick or anything else as well?
I'll repeat:
As I already said- if I for some reason ( real case can be only by
accident ) will delete file this will not be detected by self-heal
daemon, and, thus, will lead to lower replication level, i.e.
lower failure tolerance.
To prevent such accidents you need to set selinux policies so that
files under the brick are not modified by accident by any user. At
least that is the solution I remember when this was discussed 3-4
years back.
So only supported platfrom is linux? Or, may be, it is better to improve
self-healing to detect missing or wrong length files, I guess this is
very low cost in terms of host resources operation.
Just a suggestion, may be we need to look to alternatives in near future....
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