File changes propagating in older snapshots: what am I doing wrong?
Andrea
tech_lists at mail.com
Fri Apr 7 04:21:45 PDT 2017
Hi, with help form this list I've set-up my main main workstation and
almost ported all my work to DragonFly BSD (thanks!)
Now I'm moving all my data and but I'm left with one problem I'm not
able to sort out: some of the changes to files are propagated in older
snapshots! It's obviously impossible so or I've done something horribly
wrong during disk set-up or I don't understand how snapshots works.
The "short" version:
1) /home/andrea/ is my home directory in a master PFS
2) /home/attic/ is another directory in another master PFS
3) Both PFSs have a snapshot done yesterday.
4) If I add or remove files sometimes changes are not visible in
yesterday's snapshots, but sometimes they are.
As an example, today I've added (added, not modified) this file:
% ls -l /home/attic/disk_stats.txt
-rw-r--r-- 1 andrea wheel 167 Apr 7 11:38 /home/attic/disk_stats.txt
And I found it in yesterday's snapshot:
% ls -l /var/hammer/home/attic/snap-20170406-0957/disk_stats.txt
-rw-r--r-- 1 andrea wheel 167 Apr 7 11:37
/var/hammer/home/attic/snap-20170406-0957/disk_stats.txt
File date in the snapshot is 1 minute earlier than original but the file
shouldn't be there at all.
5) Another example: today I moved a whole directory from /home/attic/ to
/home/andrea/ and:
- It disappeared from /home/attic/ yesterday's snapshot
- It appeared in /home/andrea/ yesterday's snapshot
- Files in /home/andrea/ kept the last modify dates while files in the
snapshot have the date of the moment I moved the directory
6) I'm 100% sure I didn't move file directly inside the snapshot directory
Some details:
1) OS version is DragonFly v4.8.0-RELEASE #4
2) Both directories /home/andrea/ and /home/attic/ are mirrored on a
second disk.
3) This is the output of snapls and pfs-status for /home/andrea/:
# hammer snapls /home/andrea/
Snapshots on /home/andrea/ PFS#1
Transaction ID Timestamp Note
0x0000000000000000 2017-04-06 09:57:34 CEST -
# hammer pfs-status /home/andrea/
/home/andrea/ PFS#1 {
sync-beg-tid=0x0000000000000001
sync-end-tid=0x00000001183f03c0
shared-uuid=f030302c-1895-11e7-b1dd-714d7b6e28cc
unique-uuid=f0303031-1895-11e7-b1dd-714d7b6e28cc
label=""
prune-min=00:00:00
operating as a MASTER
snapshots directory defaults to /var/hammer/<pfs>
}
4) Here I find my snapshot for /home/andrea/:
# ls -l /var/hammer/home/andrea/snap-20170406-0957
lrwxr-xr-x 1 root wheel 33 Apr 6 09:57
/var/hammer/home/andrea/snap-20170406-0957 ->
/home/andrea/@@0x0000000000000000
5) The output of snapls and pfs-status for /home/attic/:
% hammer snapls /home/attic/
Snapshots on /home/attic/ PFS#2
Transaction ID Timestamp Note
0x0000000000000000 2017-04-06 09:57:34 CEST -
% hammer pfs-status /home/attic/
/home/attic/ PFS#2 {
sync-beg-tid=0x0000000000000001
sync-end-tid=0x000000011840a4b0
shared-uuid=7bb3b3bc-18ab-11e7-9d0e-714d7b6e28cc
unique-uuid=7bb3b3e1-18ab-11e7-9d0e-714d7b6e28cc
label=""
prune-min=00:00:00
operating as a MASTER
snapshots directory defaults to /var/hammer/<pfs>
}
6) Here I find my snapshot for /home/attic:
% ls -l /var/hammer/home/attic/snap-20170406-0957
lrwxr-xr-x 1 root wheel 32 Apr 6 09:57
/var/hammer/home/attic/snap-20170406-0957 ->
/home/attic/@@0x0000000000000000
7) I try to reproduce the problem but everything seems ok:
I delete a file in my home directory and I still find it in the snapshot:
$ rm /home/andrea/0
$ ls /home/andrea/0 /var/hammer/home/andrea/snap-20170406-0957/0
ls: /home/andrea/0: No such file or directory
/var/hammer/home/andrea/snap-20170406-0957/0
Now I add a file in my home directory and I don't find it in yesterday's
snapshot:
$ touch xxx
$ ls -1 /home/andrea/xxx /var/hammer/home/andrea/snap-20170406-0957/xxx
ls: /var/hammer/home/andrea/snap-20170406-0957/xxx: No such file or
directory
/home/andrea/xxx
8) But, I moved a directory in my home directory *today* and I find it
in *yesterday's* snapshot:
% ls -l /home/andrea/bin/ | grep launcher
-rwxr-xr-x 1 andrea wheel 57 Jun 11 2013 ll.urxvt_launcher
% ls -l /var/hammer/home/andrea/snap-20170406-0957/bin/ | grep launcher
-rwxr-xr-x 1 andrea wheel 57 Apr 7 11:42 ll.urxvt_launcher
In other words: today I added the whole /bin directory inside my home
and I find it in yesterday's snapshot. Files in my home directory have
the original dates (2013 in this case) while version in the snapshot
have the date of the moment I added the files. As you can see from the
output above there's a file dated 2017-04-07 inside the snapshot dated
2017-04-06 which should be impossible
9) In the source directory the directory disappeared from yesterday's
snapshots.
10) I didn't mess with the snapshot directories directly (I double
checked my command history to be sure).
I'm completely lost here, any suggestion about what I'm doing wrong or
what I can do to diagnose further?
Regards,
Andrea
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