[445] in SIPB-AFS-requests
readonly and backup volumes and the backup software
daemon@ATHENA.MIT.EDU (qjb@ATHENA.MIT.EDU)
Tue May 7 01:12:25 1991
From: qjb@ATHENA.MIT.EDU
Date: Tue, 7 May 91 01:11:34 -0400
To: jik@pit-manager.MIT.EDU
Cc: sipb-afsreq@ATHENA.MIT.EDU, bug-afs@ATHENA.MIT.EDU
In-Reply-To: "Jonathan I. Kamens"'s message of Mon, 6 May 91 22:37:50 -0400 <9105070237.AA03197@pit-manager.MIT.EDU>
Date: Mon, 6 May 91 22:37:50 -0400
From: "Jonathan I. Kamens" <jik@pit-manager.MIT.EDU>
Sender: jik@pit-manager.MIT.EDU
It appears that the "vos backup" operation backs up a read-only copy
of a volume if it exists, rather than backing up the read-write copy.
I wanted to restore a file that existed a few hours ago in my sipb
volume. I made a mount point for sipb.mit.edu:user.jik.backup and
cd'd into it. The file wasn't there, despite the fact that vos
volinfo on the volume said it was created earlier tonight. I did the
same thing for sipb.mit.edu:user.jik.readonly, and the file wasn't
there either, and the volume was several months old.
So, I did "vos release" and then "vos backup" on my volume, after
which my newest files appears in both the readonly and backup volumes.
It seems to me therefore, that if we are not going to do automatic vos
releases on all of the volumes we back up each week, we have to delete
their readonly volumes.
Please let me know if I have made a mistake somewhere here.
jik
Well, my first reaction was that this must be impossible since
the backup is a clone of the original data whereas the readonly
volume is an actual copy (unless it is on the same disk, but
even then, it is treated differently form the readonly volume).
To test what you were describing, I tried some experiments all
of which seemed to confirm your suspicion. Then, however, I
tried one additional thing: fs df on the backup volume. The
volume I used was called test. I made a mountpoint to the
read-write, read only, and backup volumes. If I did fs df on
the backup volume and no readonly volume existed, it said
"test.backup". If I did this when the readonly volume existed,
it said "test.readonly" even though fs lsm showed
soup.mit.edu:test.backup. In other words, the problem here
seems to be that a mountpoint to backup volume brings you to the
readonly volume instead of the backup volume if the readonly
volume exists. I am not sure whether this is another Transarc
misfeature or whether this is a genuine bug. I also don't know
whether there is any way to get to the backup volume (other than
a vos dump or something like that) when the readonly volume
exists. This is definitely a problem for reasons you have
described. Attached to the end of this message is the
typescript of the command I used for my experiment. I don't
have time, unfortunately, to grovel around through afs source
code to try to figure out what's really going on here. I won't
have time to do this before leaving... Oh well.
Also, "vos volinfo" is out of date syntax. The "correct"
command is now "vos examine". The old form is left in for
backward compatability. (Not that this really matters...)
Jay
Script started on Tue May 7 00:49:26 1991
% mkdir afstest
% cd afstest
% ls
% vos create soup a test -v
Volume test 536871478 created and brought online
Created the VLDB entry for the volume test 536871478
Volume 536871478 created on partition /vicepa of soup
% fs mkmount a soup.mit.edu:test -rw
% fs mkmount b soup.mit.edu:test.readonly
% fs mkmount c soup.mit.edu:test.backup
% chown qjb a
% fs sa a qjb all
% alias d date \>\! \!:1/now
% d a
% cat a/now
Tue May 7 00:50:58 EDT 1991
% ls b
b not found (Connection timed out)
% ls c
c not found (Connection timed out)
% vos backup test -v
Creating a new backup clone 536871480 ...done
Created backup volume for test
% fs checkb
All backup volumes checked.
% cat c/now
Tue May 7 00:50:58 EDT 1991
% cat b/now
b/now: Connection timed out
Exit 1 cat b/now
% vos addsite soup b test -v
Adding a new site ... done
Added replication site soup /vicepb for volume test
% cat b/now
b/now: Connection timed out
Exit 1 cat b/now
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 invalid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepb RO Site
This is a complete release of the volume 536871478
Creating a new volume 536871479 on the replication site ... done
Starting the dump from 536871481 to 536871479 ... done
Deleting the releaseClone 536871481 ... done
updating VLDB ... done
Released volume test successfully
% cat b/now
b/now: Connection timed out
Exit 1 cat b/now
% fs checkb
All backup volumes checked.
% cat b/now
Tue May 7 00:50:58 EDT 1991
% date >! a/now
% vos backup test -v
Re-cloning backup volume 536871480 ...done
Created backup volume for test
% cat a/now
Tue May 7 00:52:19 EDT 1991
% fs checkb
All backup volumes checked.
% cat b/now
Tue May 7 00:50:58 EDT 1991
% cat c/now
Tue May 7 00:50:58 EDT 1991
% vos remove soup b test.readonly -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepb RO Site
Trying to delete the volume 536871479 ... done
Volume 536871479 on partition /vicepb server soup deleted
% fs checkb
All backup volumes checked.
% cat c/now
Tue May 7 00:52:19 EDT 1991
% cat a/now
Tue May 7 00:52:19 EDT 1991
% vos addsite soup a test -v
Adding a new site ... done
Added replication site soup /vicepa for volume test
% cat b/now
b/now: No such device
Exit 1 cat b/now
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 invalid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepa RO Site
This is a complete release of the volume 536871478
Readonly volume on same partition as read/write volume, just cloning it.
updating VLDB ... done
Released volume test successfully
% fs checkb
All backup volumes checked.
% cat b/now
Tue May 7 00:52:19 EDT 1991
% date >! a/now
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepa RO Site
This is a complete release of the volume 536871478
Readonly volume on same partition as read/write volume, just cloning it.
updating VLDB ... done
Released volume test successfully
% cat a/now
Tue May 7 00:54:31 EDT 1991
% fs checkb
cat All backup volumes checked.
% cat b/now
Tue May 7 00:54:31 EDT 1991
% cat c/now
Tue May 7 00:54:31 EDT 1991
% date >! c/now
c/now: Read-only file system
Exit 1 date > c/now
% date >! b/now
b/now: Read-only file system
Exit 1 date > b/now
% date >! a/now
% cat c/now
Tue May 7 00:54:31 EDT 1991
% cat a/now
Tue May 7 00:55:17 EDT 1991
% cat b/now
Tue May 7 00:54:31 EDT 1991
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepa RO Site
This is a complete release of the volume 536871478
Readonly volume on same partition as read/write volume, just cloning it.
updating VLDB ... done
Released volume test successfully
% cat c/now
Tue May 7 00:54:31 EDT 1991
% cat b/now
Tue May 7 00:54:31 EDT 1991
% cat a/now
Tue May 7 00:55:17 EDT 1991
% fs checkb
cat All backup volumes checked.
% cat c/now
Tue May 7 00:55:17 EDT 1991
% cat b/now
Tue May 7 00:55:17 EDT 1991
% date >! a/now
% vos backup test -v
Re-cloning backup volume 536871480 ...done
Created backup volume for test
% fs checkb
All backup volumes checked.
% cat a/now
Tue May 7 00:56:08 EDT 1991
% cat b/now
Tue May 7 00:55:17 EDT 1991
% cat c/now
Tue May 7 00:55:17 EDT 1991
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepa RO Site
This is a complete release of the volume 536871478
Readonly volume on same partition as read/write volume, just cloning it.
updating VLDB ... done
Released volume test successfully
% fs checkb
All backup volumes checked.
% cat a/now
Tue May 7 00:56:08 EDT 1991
% cat b/now
Tue May 7 00:56:08 EDT 1991
% cat c/now
Tue May 7 00:56:08 EDT 1991
% vos remove soup a test.readonly -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepa RO Site
Trying to delete the volume 536871479 ... done
Volume 536871479 on partition /vicepa server soup deleted
% fs checkb
All backup volumes checked.
% vos addsite soup b test -v
Adding a new site ... done
Added replication site soup /vicepb for volume test
% date >! a/now
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 invalid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepb RO Site
This is a complete release of the volume 536871478
Creating a new volume 536871479 on the replication site ... done
Starting the dump from 536871482 to 536871479 ... done
Deleting the releaseClone 536871482 ... done
updating VLDB ... done
Released volume test successfully
% fs checkb
All backup volumes checked.
% cat a/now
Tue May 7 00:57:24 EDT 1991
% cat b/now
Tue May 7 00:57:24 EDT 1991
% cat c/now
Tue May 7 00:57:24 EDT 1991
% date >! a/now
% vos release test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepb RO Site
This is a complete release of the volume 536871478
Bringing the existing ro volume 536871479 uptodate ... done
Deleting the releaseClone 536871483 ... done
updating VLDB ... done
Released volume test successfully
% fs checkb
All backup volumes checked.
% cat a/now
Tue May 7 00:57:49 EDT 1991
% cat b/now
Tue May 7 00:57:49 EDT 1991
% cat c/now
Tue May 7 00:57:49 EDT 1991
% fs df c
Volume Name kbytes used avail %used
test.readonly 31671 6571 25100 21%
% fs df b
Volume Name kbytes used avail %used
test.readonly 31671 6571 25100 21%
% fs lsm c
'c' is a mount point for volume '#soup.mit.edu:test.backup'
% date >! a/now
% cat a/now
Tue May 7 00:58:53 EDT 1991
% cat b/now
Tue May 7 00:57:49 EDT 1991
% cat c/now
Tue May 7 00:57:49 EDT 1991
% vos backup test -v
Re-cloning backup volume 536871480 ...done
Created backup volume for test
% fs checkb
All backup volumes checked.
% cat a/now
Tue May 7 00:58:53 EDT 1991
% cat b/now
Tue May 7 00:57:49 EDT 1991
% cat c/now
Tue May 7 00:57:49 EDT 1991
% fs df c
Volume Name kbytes used avail %used
test.readonly 31671 6571 25100 21%
% vos remove soup b test.readonly -v
test
readWriteID 536871478 valid
readOnlyID 536871479 valid
backUpID 536871480 valid
number of sites -> 2
server SOUP.MIT.EDU partition /vicepa RW Site
server SOUP.MIT.EDU partition /vicepb RO Site
Trying to delete the volume 536871479 ... done
Volume 536871479 on partition /vicepb server soup deleted
% fs checkb
cat /All backup volumes checked.
% cat c/now
Tue May 7 00:58:53 EDT 1991
% fs df c
Volume Name kbytes used avail %used
test.backup 59730 41013 18717 69%
% vos remove soup a test -v
test
readWriteID 536871478 valid
readOnlyID 536871479 invalid
backUpID 536871480 valid
number of sites -> 1
server SOUP.MIT.EDU partition /vicepa RW Site
Trying to delete the volume 536871478 ... done
Trying to delete the backup volume 536871480 ... done
Last reference to the rw volume 536871478 - deleting VLDB entry
Volume 536871478 on partition /vicepa server soup deleted
% fs checkb
All backup volumes checked.
% ls a
a not found (No such device)
% ls b
b not found (No such device)
% ls c
c not found (No such device)
% exit
Script done on Tue May 7 01:00:32 1991
