Swap not getting enabled.

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m ahuja

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Jul 30, 2017, 12:58:25 PM7/30/17

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I do the following command in a series of commands.

I make swap using fallocate -l 65G & chmod 0600

I /sbin/mkswap /mnt/../../swapXXX

I /bin/echo -en '\n/mnt../../swapXXX swap swap auto 0 0\n' >> /etc/fstab

I then do the following and it fails. What am I doing wrong?

exec { "attach swap file":

command => "/sbin/swapon -af -p 1",

require => Exec["make fstab entry"],

unless => "/sbin/swapon -s | grep /mnt/ephemeral0/cassandra/swap65G",

} ->

From log file:

/Stage[main]/Ax::Cassandra::Node/Exec[attach swap file]/returns: executed successfully

dmesg shows

"Adding 68157436k swap on /mnt/ephemeral0/../swap65G. Priority:1 extents:45 across:72851452k SSFS"

free -m

total used free shared buffers cached

Mem: 3774 3213 561 8 106 1646

-/+ buffers/cache: 1460 2314

Swap: 0 0 0

No swap.

But if I run the command on command line it runs fine.

If I do a puppet apply --debug --version it works fine.

The puppet file is applied as root.

WHAT am I doing wrong? It's messing with my mind.

sudo /sbin/swapon -af -p 1

admin@:~$ free -m

total used free shared buffers cached

Mem: 3774 3232 542 8 106 1646

-/+ buffers/cache: 1479 2295

Swap: 66559 0 66559

Dmesg now has two entries!

[Sun Jul 30 02:34:54 2017] Adding 68157436k swap on /mnt/ephemeral0/cassandra/swap65G. Priority:1 extents:45 across:72851452k SSFS

[Sun Jul 30 02:50:43 2017] Adding 68157436k swap on /mnt/ephemeral0/cassandra/swap65G. Priority:1 extents:45 across:72851452k SSFS

Really whats going on?

jcbollinger

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Jul 31, 2017, 9:51:35 AM7/31/17

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On Sunday, July 30, 2017 at 11:58:25 AM UTC-5, m ahuja wrote:

I do the following command in a series of commands.
I make swap using fallocate -l 65G & chmod 0600
I /sbin/mkswap /mnt/../../swapXXX
I /bin/echo -en '\n/mnt../../swapXXX swap swap auto 0 0\n' >> /etc/fstab

You really ought to use a Mount resource to manage the /etc/fstab entry, but that's surely unrelated to the problem you describe.

I then do the following and it fails. What am I doing wrong?

exec { "attach swap file":
command => "/sbin/swapon -af -p 1",
require => Exec["make fstab entry"],
unless => "/sbin/swapon -s | grep /mnt/ephemeral0/cassandra/swap65G",
} ->

From log file:

/Stage[main]/Ax::Cassandra::Node/Exec[attach swap file]/returns: executed successfully

Puppet seems to disagree with you: the command does not fail, in the sense that its exit status is not different from 0.

dmesg shows
"Adding 68157436k swap on /mnt/ephemeral0/../swap65G. Priority:1 extents:45 across:72851452k SSFS"

And that seems to confirm that it did not fail.

free -m
total used free shared buffers cached
Mem: 3774 3213 561 8 106 1646
-/+ buffers/cache: 1460 2314
Swap: 0 0 0

No swap.

But that is indeed odd.

But if I run the command on command line it runs fine.
If I do a puppet apply --debug --version it works fine.

Did you mean "--verbose"? Anyway, it is odd if the effect on the system varies with the use of the --debug or --verbose option, but it is not clear whether those are the only things that differ between the run that has the result you want and the one that doesn't.

You haven't given us (or at least me) enough to work with. I would like to see a complete manifest that is sufficient to demonstrate the problem, together with sufficient procedural instructions for how to reproduce the incorrect behavior. Until I see those, my best guess is that in your success case you apply a different, more narrowly-scoped starting manifest, and there is something else being applied in the failure case that causes the swap file to be disabled before the end of the run.