Some explanation: zone backup or restore is performed as a zone "event". When zone events are invoked via the knotc interface, it typically works in the way that the event is planned to be performed later and "OK" is returned just as an info that the command has been registered. The event (zone backup in this case) happens per-zone and with some delay, when some background-worker becomes available, and the outcome appears in the log. On the contrary, if knotc is invoked with `-b` parameter, it waits for the event to be performed synchronously, and collects the outcome of the whole process (some error code handligs of this are currently subject to ongoing improvements by my colleagues).

So, from the strace you sent me, I only see that some initialization has been done and that the early "OK" has been returned, but there are no traits of the backup process as such :(

Could you please collect somewhat longer strace, by watching when the backup finishes in the logfile?

Thanks!

Libor

Dne 09. 12. 20 v 15:56 Thomas E. napsal(a):
Hi Libor,

yes, the backup command was executed and confirmed with "OK":

root@signer-0:/# knotc zone-backup +backupdir /tmp/backup
OK

I did it again and the output is the same.

Thanks,
Thomas

On 09.12.20 15:42, libor.peltan wrote:
Hi Thomas,

are you sure this strace has been collected while the issue was
reproduced and half of the keys copied again?

Maybe you just have deattached strace too early(?).

Libor

Dne 09. 12. 20 v 15:00 Thomas E. napsal(a):
Hi Libor,

sure, here is the output:


root@signer-0:/tmp/backup/keys/keys# strace -p 9781
strace: Process 9781 attached
restart_syscall(<... resuming interrupted restart_syscall ...>) = 1
accept4(16, NULL, NULL, SOCK_NONBLOCK)  = 23
recvmsg(23, {msg_namelen=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = -1 EAGAIN
(Resource temporarily unavailable)
poll([{fd=23, events=POLLIN}], 1, 5000) = 1 ([{fd=23, revents=POLLIN}])
recvmsg(23, {msg_name=NULL, msg_namelen=0,
msg_iov=[{iov_base="\1\20\0\vzone-backup\21\0\0\32\0\v/tmp/backup"...,
iov_len=262144}], msg_iovlen=1, msg_controllen=0, msg_flags=0},
MSG_DONTWAIT|MSG_NOSIGNAL) = 37
write(6, "2020-12-09T13:57:12+0000 info: c"..., 71) = 71
stat("/var/lib/knot/catalog/data.mdb", 0x7ffd0fb9f090) = -1 ENOENT (No
such file or directory)
stat("/var/lib/knot/journal/data.mdb", {st_mode=S_IFREG|0660,
st_size=9936896, ...}) = 0
stat("/var/lib/knot/keys/data.mdb", {st_mode=S_IFREG|0660,
st_size=45056, ...}) = 0
mkdir("/tmp/backup", 0770)              = 0
openat(AT_FDCWD, "/tmp/backup/knot.backup.lockfile",
O_RDONLY|O_CREAT|O_EXCL, 0600) = 24
mkdir("/tmp/backup", 0750)              = -1 EEXIST (File exists)
stat("/var/lib/knot/catalog/data.mdb", 0x7ffd0fb9efa0) = -1 ENOENT (No
such file or directory)
futex(0x7ffd0fb9f8e0, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x7ffd0fb9f890, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x7ffd0fb9f8e4, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x7ffd0fb9f890, FUTEX_WAKE_PRIVATE, 1) = 1
sendmsg(23, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\3",
iov_len=1}], msg_iovlen=1, msg_controllen=0, msg_flags=0},
MSG_NOSIGNAL) = 1
recvmsg(23, {msg_namelen=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = -1 EAGAIN
(Resource temporarily unavailable)
poll([{fd=23, events=POLLIN}], 1, 5000) = 1 ([{fd=23, revents=POLLIN}])
recvmsg(23, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\0",
iov_len=262144}], msg_iovlen=1, msg_controllen=0, msg_flags=0},
MSG_DONTWAIT|MSG_NOSIGNAL) = 1
close(23)                               = 0
poll([{fd=16, events=POLLIN}], 1, -1


Thomas



On 09.12.20 13:34, libor.peltan wrote:
Hi Thomas,

would you try attaching `strace` to the running Knot and try the backup
again, in order to see if some syscall(s) return error codes?

Thanks much!

Libor

Dne 09. 12. 20 v 12:25 Thomas E. napsal(a):
Hi Libor,


# knotc -V
knotc (Knot DNS), version 3.0.2


Thomas

On 09.12.20 12:16, libor.peltan wrote:
Hi Thomas,

aren't you using Knot version 3.0.0 (thus lower than 3.0.1) ?

Libor

Dne 09. 12. 20 v 11:39 Thomas E. napsal(a):
Hi Libor,

I deleted the backup directory a few times, but I receive the same
error
every time:

2020-12-09T10:31:52+0000 info: control, received command
'zone-backup'
2020-12-09T10:31:52+0000 warning: [xxx.] zone backup failed (not
exists)
2020-12-09T10:31:52+0000 error: [xxx.] zone event 'backup/restore'
failed (not exists)
2020-12-09T10:31:52+0000 warning: [yyy.] zone backup failed (not
exists)
2020-12-09T10:31:52+0000 error: [yyy.] zone event 'backup/restore'
failed (not exists)



One of the keys is the ZSK of zone xxx and the oterh the KSKS of zone
yyy.


root@signer-0:/#  keymgr xxx list human | grep
1fb3900b2e5ac72d30f927016ea4546ca561a5da

1fb3900b2e5ac72d30f927016ea4546ca561a5da ksk=no  zsk=yes tag=39969
algorithm=7  size=1024 public-only=no  pre-active=0
publish=-1M3D17h49m4s ready=0 active=-1M3D17h49m4s retire-active=0
retire=0 post-active=0 revoke=0 remove=0


root@signer-0:/#  keymgr yyy list human | grep
087cc573318e070befff1d9cbcf07e3b5cf5444d

087cc573318e070befff1d9cbcf07e3b5cf5444d ksk=yes zsk=no  tag=37419
algorithm=7  size=2048 public-only=no  pre-active=0
publish=-1M3D18h11m7s ready=-1M3D18h11m7s active=-26D12h49m4s
retire-active=0 retire=0 post-active=0 revoke=0 remove=0

Best regards,
Thomas

On 09.12.20 11:15, libor.peltan wrote:
Hi Thomas,

could you please try if this issue is reproducible: if whenever you
attempt the backup (to a fresh empty target directory), it fails
with
"not exists"?

Could you please check if the keys that happen to make it to the
backup
belong to the same zone, or that it's one from each zone? (You
light use
`keymgr list` to check which key ID belongs to which zone.)

Thanks,

Libor

Dne 08. 12. 20 v 21:36 Thomas napsal(a):
Hi Libor,

sorry, I was really too unspecific.

I'm hosting 2 zones. These 4 keys are on the production machine:

root@signer-0:/var/lib/knot/keys/keys# ls -alh


-rw-r----- 1 knot knot 1,7K Nov  5 16:22
087cc573318e070befff1d9cbcf07e3b5cf5444d.pem
-rw-r----- 1 knot knot  916 Nov  5 16:44
1fb3900b2e5ac72d30f927016ea4546ca561a5da.pem
-rw-r----- 1 knot knot  916 Nov  5 16:22
6ebb8eb3ec2ddaf150119b4bc11b47dcec91621a.pem
-rw-r----- 1 knot knot 1,7K Nov  5 16:44
d7e47e2909f4d5947d8fb8684cb79ed06feb4b0a.pem


Performing a backup with the following command:

# knotc zone-backup +backupdir /tmp/backup

Backup directory after performing the backup shows:

root@signer-0:/tmp/backup/keys/keys# ls -ahl

-rw-r----- 1 knot knot 1,7K Dez  8 20:21
087cc573318e070befff1d9cbcf07e3b5cf5444d.pem
-rw-r----- 1 knot knot  916 Dez  8 20:21
1fb3900b2e5ac72d30f927016ea4546ca561a5da.pem

2 keys are missing.

Hhmm ok, there is an error in the log:

2020-12-08T20:26:43+0000 info: control, received command
'zone-backup'
2020-12-08T20:26:43+0000 warning: [xxx.] zone backup failed (not
exists)
2020-12-08T20:26:43+0000 error: [xxx.] zone event 'backup/restore'
failed (not exists)
2020-12-08T20:26:43+0000 warning: [yyy.] zone backup failed (not
exists)
2020-12-08T20:26:43+0000 error: [yyy.] zone event 'backup/restore'
failed (not exists)

I'm using the latest knot version.


Best regards,

Thomas



Am 08.12.20 um 16:56 schrieb libor.peltan:
Hi Thomas,

could you be more specific about "half of private keys were in the
backup" ? How many were, how many weren't, and was there some
obvious
difference between them?

Could you share the log snippets covering the backup and the
restore
procedures?

Thanks,

Libor

Dne 08. 12. 20 v 16:48 Thomas E. napsal(a):
Hi (again),

I was trying to backup and restore a server with the new knotc
zone-backup/restore command.

I recognized that only half of the private keys were in the
backup,
which leads to an error:

2020-12-08T14:44:00+0100 error: [xxx.] DNSSEC, failed to load
private
keys (not exists)
2020-12-08T14:44:00+0100 error: [xxx.] DNSSEC, failed to load
keys
(not
exists)

Shouldn't the backup contain all private keys?


Thanks,
Thomas
--
https://lists.nic.cz/mailman/listinfo/knot-dns-users

Reply via email to