Date: Tue, 10 Oct 2017 13:35:34 -0400 From: Juan Manuel Palacios <juan@kognito.com> To: freebsd-fs@freebsd.org Subject: Re: Trying to understand confusing 'zfs diff' output Message-ID: <CAFzR3-r5SbGdspYFt5G-mME=Qo=24uj7Raco4L1c7%2BtawADjOA@mail.gmail.com> In-Reply-To: <CAFzR3-pujG68fWfnUxD%2BeaYfrMKAaScUmO-fTLMkgbuuH-bKgg@mail.gmail.com> References: <CAFzR3-pujG68fWfnUxD%2BeaYfrMKAaScUmO-fTLMkgbuuH-bKgg@mail.gmail.com>
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Hi everyone,
I sent this question some weeks ago but got no response. Pinging again to
see if anyone has any clues, thanks!
On Tue, Sep 19, 2017 at 12:13 PM, Juan Manuel Palacios <juan@kognito.com>
wrote:
> Hi everyone,
>
> I'm trying to understand a result I'm seeing when comparing the diff of
> two local ZFS snapshots that were successfully replicated to a remote pool
> over SSH against the diff of their remote counterparts. The latter shows
> three files as having been deleted, while the local diff of the exact same
> two snapshots doesn't.
>
> Following are those diffs, with empty lines entered manually into the
> local diff where the remote one shows the deleted files; moreover, lines
> right above & below this confusing part of the diffs have been trimmed for
> brevity's sake, since they were identical across both outputs.
>
> 1) Local diff (FreeBSD 10.3-RELEASE-p21 system):
>
> -> zfs diff zroot/mysql@automated_2017-07-31_23:45:04-EDT
> zroot/mysql@automated_2017-08-01_23:45:03-EDT | gawk '{ match($2,
> /\/(.*)/, matches); printf "%s\t%s\n", $1, matches[1]; }'
> (trimmed)
> M mysql/data/knet@002dlrs/lrs_providers.ibd
>
> M mysql/data/snap/sessions.ibd
> M mysql/data/knet@002dlrs/sessions.ibd
> M mysql/data/leads/demo_requests.ibd
> M mysql/tmp/nk-dev.sql.gz
>
>
> M mysql/data/knet/account_manager_memberships.ibd
> (trimmed)
>
>
> 2) Remote diff (FreeBSD 10.3-RELEASE-p19 system):
>
> -> zfs diff backup/mysql@automated_2017-07-31_23:45:04-EDT
> backup/mysql@automated_2017-08-01_23:45:03-EDT | gawk '{ match($2,
> /\/mnt\/backup\/(.*)/, matches); printf "%s\t%s\n", $1, matches[1]; }'
> (trimmed)
> M mysql/data/knet@002dlrs/lrs_providers.ibd
> - mysql/tmp/nk-dump--2017-07-19_01:32:16-EDT.sql
> M mysql/data/snap/sessions.ibd
> M mysql/data/knet@002dlrs/sessions.ibd
> M mysql/data/leads/demo_requests.ibd
> M mysql/tmp/nk-dev.sql.gz
> - mysql/replication/mysql-bin.001241
> - mysql/replication/mysql-bin.001242
> M mysql/data/knet/account_manager_memberships.ibd
> (trimmed)
>
> So, as I was saying, the remote diff shows these three files as having
> been deleted, because they were:
>
> 1) Locally:
>
> -> ls -l /mysql/.zfs/snapshot/automated_2017-07-31_23\:45\:04-EDT/
> tmp/nk-dump--2017-07-19_01\:32\:16-EDT.sql
> -rw-r--r-- 1 jmpp jmpp 46M Jul 19 01:32 /mysql/.zfs/snapshot/automated
> _2017-07-31_23:45:04-EDT/tmp/nk-dump--2017-07-19_01:32:16-EDT.sql
>
> -> ls -l /mysql/.zfs/snapshot/automated_2017-08-01_23\:45\:03-EDT/
> tmp/nk-dump--2017-07-19_01\:32\:16-EDT.sql
> ls: /mysql/.zfs/snapshot/automated_2017-08-01_23:45:03-EDT/tmp/
> nk-dump--2017-07-19_01:32:16-EDT.sql: No such file or directory
>
>
> 2) On the remote pool:
>
> -> ls -l /mnt/backup/mysql/.zfs/snapshot/automated_2017-07-31_23\:45\
> :04-EDT/tmp/nk-dump--2017-07-19_01:32:16-EDT.sql
> -rw-r--r-- 1 1001 1001 48288840 Jul 18 22:32
> /mnt/backup/mysql/.zfs/snapshot/automated_2017-07-31_23:45:
> 04-EDT/tmp/nk-dump--2017-07-19_01:32:16-EDT.sql
>
> -> ls -l /mnt/backup/mysql/.zfs/snapshot/automated_2017-08-01_23\:45\
> :03-EDT/tmp/nk-dump--2017-07-19_01:32:16-EDT.sql
> ls: /mnt/backup/mysql/.zfs/snapshot/automated_2017-08-01_23:45:
> 03-EDT/tmp/nk-dump--2017-07-19_01:32:16-EDT.sql: No such file or directory
>
> And so for the other two files.
>
> So, my question is, if the remote diff is correct in showing these files
> as having been deleted between the two snapshots (it *is* correct in doing
> that, right?), why does the local diff not show it also?
>
> Thanks in advance for any help!
>
> --
> Juan Palacios
> Senior Software Architect
> <http://www.kognito.com>;
> 135 West 26th St l 12th Floor l NY, NY 10001
> 212.675.9234 <(212)%20675-9234> l 646.217.3677 <(646)%20217-3677>
>
> Register for our upcoming webinar with The Healthy Minds Network and
> AUCCCD:
> Trends in Higher Education Mental Health: Research Highlights
> <https://go.kognito.com/higheredtrendswebinar2017>;
>
> Connect with us!
> <http://twitter.com/kognito>; <http://www.linkedin.com/company/kognito>;
> <http://www.facebook.com/KognitoConversations/>;
> <http://www.youtube.com/channel/UC1cyckrxa_lCegQMT2HPS-w>;
>
--
Juan Palacios
Senior Software Architect
<http://www.kognito.com>;
135 West 26th St l 12th Floor l NY, NY 10001
212.675.9234 l 646.217.3677
Register for our upcoming webinar with The Healthy Minds Network and
AUCCCD:
Trends in Higher Education Mental Health: Research Highlights
<https://go.kognito.com/higheredtrendswebinar2017>;
Connect with us!
<http://twitter.com/kognito>; <http://www.linkedin.com/company/kognito>;
<http://www.facebook.com/KognitoConversations/>;
<http://www.youtube.com/channel/UC1cyckrxa_lCegQMT2HPS-w>;
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