Re: [BackupPC-users] Phantom host

[Bzzzz]

On Fri, 27 Oct 2017 14:18:28 -0700
Ethan Tarr  wrote:

> I resolved the issue by deleting the laptop’s DHCP entries on the PDC,
> then running ipconfig /release -> /flushdns/ -> /renew -> /registerdns
> on the laptop itself. Now it has a different IP assigned through DHCP,
> which is being properly registered in the DNS forward lookup zone, and
> the BackupPC machine can now resolve the name.

A, where would be admins without ze windoze touch?!! *<;-p)

Anyway, ziziz nice!

> Sent from 10 Windows for horse Mail

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Re: [BackupPC-users] Phantom host

[Ethan Tarr]

Thanks for the help, guys.

I resolved the issue by deleting the laptop’s DHCP entries on the PDC, then 
running ipconfig /release -> /flushdns/ -> /renew -> /registerdns on the laptop 
itself. Now it has a different IP assigned through DHCP, which is being 
properly registered in the DNS forward lookup zone, and the BackupPC machine 
can now resolve the name.

Sent from Mail for Windows 10

From: Les Mikesell
Sent: Friday, October 27, 2017 12:17 PM
To: General list for user discussion, questions and support
Subject: Re: [BackupPC-users] Phantom host

On Fri, Oct 27, 2017 at 12:31 PM, Ethan Tarr  wrote:
> BackupPC is running on a dedicated Debian Jessie machine (custom built 2U).
>
> Our PDC and SDC are Windows Server 2012 (Dell servers).
>

Is the 10.1.10.3 and 10.1.10.4 DNS servers that your backuppc host is
querying those PDC/SDC boxes themselves or some other systems that
would have to be kept in sync?

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Re: [BackupPC-users] Phantom host

[Les Mikesell]

On Fri, Oct 27, 2017 at 12:31 PM, Ethan Tarr  wrote:
> BackupPC is running on a dedicated Debian Jessie machine (custom built 2U).
>
> Our PDC and SDC are Windows Server 2012 (Dell servers).
>

Is the 10.1.10.3 and 10.1.10.4 DNS servers that your backuppc host is
querying those PDC/SDC boxes themselves or some other systems that
would have to be kept in sync?

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Re: [BackupPC-users] Phantom host

[Ethan Tarr]

BackupPC is running on a dedicated Debian Jessie machine (custom built 2U).

Our PDC and SDC are Windows Server 2012 (Dell servers).

You are right, JY, the laptop in question isn’t appearing in the forward lookup 
zone. I will have to dig into that. Thanks.

Sent from Mail for Windows 10

From: Les Mikesell
Sent: Friday, October 27, 2017 10:20 AM
To: General list for user discussion, questions and support
Subject: Re: [BackupPC-users] Phantom host

On Fri, Oct 27, 2017 at 11:23 AM, Ethan Tarr  wrote:
>
> ;; Got SERVFAIL reply from 10.1.10.3, trying next server
>
> Server: 10.1.10.4
> Address:10.1.10.4#53
> ** server can't find mylaptop: SERVFAIL
>
>
> I checked DNS and DHCP on the PDC back when this first happened and the
> proper entries are still in place. Here’s what any other machine on the
> network looks like:
>

I've forgotten most of what I ever knew about windows networking, but
isn't there a client-side setting as to whether a DHCP client
registers itself into DNS?  Also, is your backuppc DNS server your PDC
or does it have to keep DNS updated to some other server for your
domain?

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Re: [BackupPC-users] Phantom host

[Les Mikesell]

On Fri, Oct 27, 2017 at 11:23 AM, Ethan Tarr  wrote:
>
> ;; Got SERVFAIL reply from 10.1.10.3, trying next server
>
> Server: 10.1.10.4
> Address:10.1.10.4#53
> ** server can't find mylaptop: SERVFAIL
>
>
> I checked DNS and DHCP on the PDC back when this first happened and the
> proper entries are still in place. Here’s what any other machine on the
> network looks like:
>

I've forgotten most of what I ever knew about windows networking, but
isn't there a client-side setting as to whether a DHCP client
registers itself into DNS?  Also, is your backuppc DNS server your PDC
or does it have to keep DNS updated to some other server for your
domain?

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 lesmikes...@gmail.com

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Re: [BackupPC-users] Phantom host

[Bzzzz]

On Fri, 27 Oct 2017 10:00:11 -0700
Ethan Tarr  wrote:

> Oh, I forgot to mention, I use rsyncd as the transport method, so even
> if samba has any issues it should still back up fine.

Whatever the method, your problem has good chances to live around the DNS
servers, as you can't resolve (both direct and reverse?) your laptop
from them, which is abnormal.

JY

> Sent from Anymanymanimoooh-2100 Telepathic Mail in 2028 for
> Windows 25.7

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Re: [BackupPC-users] Phantom host

[Ethan Tarr]

The C:\Users folder is shared.

Oh, I forgot to mention, I use rsyncd as the transport method, so even if samba 
has any issues it should still back up fine.

Sent from Mail for Windows 10

From: B
Sent: Friday, October 27, 2017 9:51 AM
To: backuppc-users@lists.sourceforge.net
Subject: Re: [BackupPC-users] Phantom host

On Fri, 27 Oct 2017 09:23:36 -0700
Ethan Tarr  wrote:

> nslookup mylaptop
> ;; Got SERVFAIL reply from 10.1.10.3, trying next server
> Server: 10.1.10.4
> Address:10.1.10.4#53
> ** server can't find mylaptop: SERVFAIL
> 
> nslookup mylaptop.mydomain.com
> Server: 10.1.10.3
> Address:10.1.10.3#53
> ** server can't find mylaptop.mydomain.com: NXDOMAIN
> 
> I checked DNS and DHCP on the PDC back when this first happened and
> the proper entries are still in place.

Test, test and re-test, especially to see if name resolution is
still failing or not when the incriminated laptop is off line.

If your DHCP srv is updating your DNS srv, check it is still the case;
if your DNS srv isn't basically updated by the DHCP srv, then you have a
DNS problem.

Other useful thing: either with and with out the criminal online, use
'arp' (pkg net-tools on Debian) as root to get a list of all resolved
(or not!) IP addresses and MAC of your network.

Oops, forgot the main issue: check laptop isn't behind a router, as they
usually do not allow broadcast packets to pass through.

> 
> The one unusual thing I can think of is that over the summer this
> laptop had a boot drive fail, so I had to wipe it and reinstall Win10.
> Maybe somehow that resulted in “two machines” sharing the same MAC
> address? I don’t know.

Neither do I, as next march it will be 19 years I dumped windows for
Debian and never ever regretted it.
 
> smbclient -U user%pass -L //mylaptop
> OS=[Windows 10 Home 15063] Server=[Windows 10 Home 6.3]
> Sharename   Type  Comment
> -     ---
> ADMIN$  Disk  Remote Admin
> C$  Disk  Default share
> Canon iR-ADV C5030C5035 Class Driver Printer   Canon iR-ADV
> C5030/C5035 Class Driver D$  Disk  Default share
> IPC$IPC   Remote IPC
> print$  Disk  Printer Drivers
> Users   Disk
> OS=[Windows 10 Home 15063] Server=[Windows 10 Home 6.3]
> Server   Comment
> ----
> WorkgroupMaster

Hm, you don't have any share?
This can be a real problem, at least for C:\

JY

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Re: [BackupPC-users] Phantom host

[Bzzzz]

On Fri, 27 Oct 2017 09:23:36 -0700
Ethan Tarr  wrote:

> nslookup mylaptop
> ;; Got SERVFAIL reply from 10.1.10.3, trying next server
> Server: 10.1.10.4
> Address:10.1.10.4#53
> ** server can't find mylaptop: SERVFAIL
> 
> nslookup mylaptop.mydomain.com
> Server: 10.1.10.3
> Address:10.1.10.3#53
> ** server can't find mylaptop.mydomain.com: NXDOMAIN
> 
> I checked DNS and DHCP on the PDC back when this first happened and
> the proper entries are still in place.

Test, test and re-test, especially to see if name resolution is
still failing or not when the incriminated laptop is off line.

If your DHCP srv is updating your DNS srv, check it is still the case;
if your DNS srv isn't basically updated by the DHCP srv, then you have a
DNS problem.

Other useful thing: either with and with out the criminal online, use
'arp' (pkg net-tools on Debian) as root to get a list of all resolved
(or not!) IP addresses and MAC of your network.

Oops, forgot the main issue: check laptop isn't behind a router, as they
usually do not allow broadcast packets to pass through.

> 
> The one unusual thing I can think of is that over the summer this
> laptop had a boot drive fail, so I had to wipe it and reinstall Win10.
> Maybe somehow that resulted in “two machines” sharing the same MAC
> address? I don’t know.

Neither do I, as next march it will be 19 years I dumped windows for
Debian and never ever regretted it.
 
> smbclient -U user%pass -L //mylaptop
> OS=[Windows 10 Home 15063] Server=[Windows 10 Home 6.3]
> Sharename   Type  Comment
> -     ---
> ADMIN$  Disk  Remote Admin
> C$  Disk  Default share
> Canon iR-ADV C5030C5035 Class Driver Printer   Canon iR-ADV
> C5030/C5035 Class Driver D$  Disk  Default share
> IPC$IPC   Remote IPC
> print$  Disk  Printer Drivers
> Users   Disk
> OS=[Windows 10 Home 15063] Server=[Windows 10 Home 6.3]
> Server   Comment
> ----
> WorkgroupMaster

Hm, you don't have any share?
This can be a real problem, at least for C:\

JY

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Re: [BackupPC-users] BPC4: checksum

[Les Mikesell]

On Fri, Oct 27, 2017 at 10:11 AM, Gandalf Corvotempesta
 wrote:
> I'm using ZFS, so checksumming is done by ZFS itself, is not an issue for me
> to skip any data corruption check, as zfs does this automatically
>
> What I would like is to keep load as low as possible on clients and
> checksumming every file is slowing down everything

I don't currently have a system running so I can't give very specific
advice, but if I were doing it I'd probably try to fix the schedule to
do fulls every 4 or 8 weeks and make them happen on weekends if that
is down time on the clients, skewing them so different large clients
get the full on different weekends and ones that complete overnight on
weekdays.Alternatively, if the target data is neatly subdivided
into top level directories, I might try to split runs to a single
large host giving it multiple names, each with different shares, using
ClientNameAlias to point it to the same target to make it possible to
split the fulls into different days so each completes in the available
time.

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Re: [BackupPC-users] BPC4: checksum

[Gandalf Corvotempesta]

Bpc is able to transfer only changed files even without checksum. If not,
incremental backups (that doesn't use checksum) won't be possible, that why
I'm asking if checksum is mandatory even for fulls

Il 27 ott 2017 6:26 PM, "Stefan Peter"  ha scritto:

> Dear Gandalf Corvotempesta
> On 27.10.2017 17:11, Gandalf Corvotempesta wrote:
> > I'm using ZFS, so checksumming is done by ZFS itself, is not an issue
> > for me to skip any data corruption check, as zfs does this automatically
>
> But this won't help BackupPC to decide which files have changed and,
> therefore, need to be transfered from the client to the server.
>
> With kind regards
>
> Stefan Peter
>
>
> --
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?
> (See https://en.wikipedia.org/wiki/Posting_style for details)
>
> 
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Re: [BackupPC-users] BPC4: checksum

[Stefan Peter]

Dear Gandalf Corvotempesta
On 27.10.2017 17:11, Gandalf Corvotempesta wrote:
> I'm using ZFS, so checksumming is done by ZFS itself, is not an issue
> for me to skip any data corruption check, as zfs does this automatically

But this won't help BackupPC to decide which files have changed and,
therefore, need to be transfered from the client to the server.

With kind regards

Stefan Peter


-- 
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Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
(See https://en.wikipedia.org/wiki/Posting_style for details)

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Re: [BackupPC-users] Phantom host

[Ethan Tarr]

DNS results:

nslookup mylaptop
;; Got SERVFAIL reply from 10.1.10.3, trying next server
Server: 10.1.10.4
Address:10.1.10.4#53
** server can't find mylaptop: SERVFAIL

nslookup mylaptop.mydomain.com
Server: 10.1.10.3
Address:10.1.10.3#53
** server can't find mylaptop.mydomain.com: NXDOMAIN

I checked DNS and DHCP on the PDC back when this first happened and the proper 
entries are still in place. Here’s what any other machine on the network looks 
like:

nslookup another-pc
Server: 10.1.10.3
Address:10.1.10.3#53
Name:   another-pc.mydomain.com
Address: 10.1.10.195

The one unusual thing I can think of is that over the summer this laptop had a 
boot drive fail, so I had to wipe it and reinstall Win10. Maybe somehow that 
resulted in “two machines” sharing the same MAC address? I don’t know.

smbclient -U user%pass -L //mylaptop
OS=[Windows 10 Home 15063] Server=[Windows 10 Home 6.3]
Sharename   Type  Comment
-     ---
ADMIN$  Disk  Remote Admin
C$  Disk  Default share
Canon iR-ADV C5030C5035 Class Driver Printer   Canon iR-ADV C5030/C5035 
Class Driver
D$  Disk  Default share
IPC$IPC   Remote IPC
print$  Disk  Printer Drivers
Users   Disk
OS=[Windows 10 Home 15063] Server=[Windows 10 Home 6.3]
Server   Comment
----
WorkgroupMaster

Thanks for your help!

Sent from Mail for Windows 10

From: B
Sent: Thursday, October 26, 2017 3:53 PM
To: backuppc-users@lists.sourceforge.net
Subject: Re: [BackupPC-users] Phantom host

On Thu, 26 Oct 2017 15:34:38 -0700
Ethan Tarr  wrote:

> Finally had a few minutes this afternoon to sort some lists of MAC
> addresses, and I couldn’t find any duplicates. This is very
> mysterious. Not a huge problem, but annoying.

Ok, from the server, can you test what is the answer of:

* a DNS request (I suppose your machines use their regular DNS names when
  resolving to NETBIOS)
$ nslookup mymachineicantreach

* a SMB listing request?
$ smbclient -Umyuser%mypassword -L //mymachinename


JY

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Re: [BackupPC-users] BPC4: checksum

[Bzzzz]

On Fri, 27 Oct 2017 17:11:26 +0200
Gandalf Corvotempesta  wrote:

> I'm using ZFS, so checksumming is done by ZFS itself, is not an issue
> for me to skip any data corruption check, as zfs does this
> automatically

ZFS is very good at this, but for data I'd like to have both belt and
suspenders (note that there's still a pending important issue about
rewriting or not when meeting a bad sector, it's mitigated if you're
using mirrors (which you should), but with RAIDZ-n, it raises the
possibility of data loss.)

But from your other post (10x slower w/ chksum), I think there's no
question that removing it is the way to go for your case.

> What I would like is to keep load as low as possible on clients and
> checksumming every file is slowing down everything

As always in IT, the best compromise for your own case is always the
best of all ;-)

JY

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Re: [BackupPC-users] BPC4: checksum

[Bzzzz]

On Fri, 27 Oct 2017 10:03:45 -0500
Les Mikesell  wrote:

>   I thought in v4 this
> mechanism is also related to the ability to match copied, moved or
> renamed files to existing matching content in the pool, so removing it
> might be a bad idea aside from eliminating the check for corruption or
> changes in content that don't update the directory/inode.

Yep, I agree with you.

JY

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Re: [BackupPC-users] BPC4: checksum

[Gandalf Corvotempesta]

I'm using ZFS, so checksumming is done by ZFS itself, is not an issue for
me to skip any data corruption check, as zfs does this automatically

What I would like is to keep load as low as possible on clients and
checksumming every file is slowing down everything

Il 27 ott 2017 5:04 PM, "Les Mikesell"  ha scritto:

On Fri, Oct 27, 2017 at 9:31 AM, B  wrote:
>
> Correction (as often,I read much too fast):
>
>> This i going against: "I don't think so, because on incrementals BPC
>> doesn't use "--checksum" at all." (v.4.x doc):
>
> The doc doesn't speak about incrementals (only fulls), but to be sure
> about this, you should look at rsync_bpc source.
>

The default for rsync is to quickly skip any files where the timestamp
and length match the existing copy.  v3 used --ignore-times on full
runs to go through the motions of transferring by comparing block
checksums and transferring any differences.  --checksum is similar but
uses a single checksum over the whole file.   I thought in v4 this
mechanism is also related to the ability to match copied, moved or
renamed files to existing matching content in the pool, so removing it
might be a bad idea aside from eliminating the check for corruption or
changes in content that don't update the directory/inode.

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Re: [BackupPC-users] BPC4: checksum

[Les Mikesell]

On Fri, Oct 27, 2017 at 9:31 AM, B  wrote:
>
> Correction (as often,I read much too fast):
>
>> This i going against: "I don't think so, because on incrementals BPC
>> doesn't use "--checksum" at all." (v.4.x doc):
>
> The doc doesn't speak about incrementals (only fulls), but to be sure
> about this, you should look at rsync_bpc source.
>

The default for rsync is to quickly skip any files where the timestamp
and length match the existing copy.  v3 used --ignore-times on full
runs to go through the motions of transferring by comparing block
checksums and transferring any differences.  --checksum is similar but
uses a single checksum over the whole file.   I thought in v4 this
mechanism is also related to the ability to match copied, moved or
renamed files to existing matching content in the pool, so removing it
might be a bad idea aside from eliminating the check for corruption or
changes in content that don't update the directory/inode.

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Re: [BackupPC-users] BPC4: checksum

[Gandalf Corvotempesta]

In my case, using checksum will slow down everything about 10 times that's
why I've asked

A full backup without checksum usually takes about 6 hours, with checksum I
need 2 days

Il 27 ott 2017 4:25 PM, "B"  ha scritto:

> On Fri, 27 Oct 2017 12:56:36 +0200
> Gandalf Corvotempesta  wrote:
>
> > What happens if I remove "--checksum" from "full" backups ?
>
> Monstrosities:
> * an A380 will holographically crash onto your house,
> * your dog/cat/children/wife/goldfish will turn gay,
> * you'll awake one morning and all your machines will be reinstalled with
>   DOS-2.0,
> * you'll dream of Bill Gates every night until you pass away,
> etc…
>
> and apart that, may be:
> http://backuppc.sourceforge.net/faq/BackupPC.html#Rsync-checksum-caching
> can help as a base; in v.4.x, there are some light differences:
> http://backuppc.sourceforge.net/BackupPC-4.1.3.html
>
> This i going against: "I don't think so, because on incrementals BPC
> doesn't use "--checksum" at all." (v.4.x doc):
>
> $Conf{RsyncFullArgsExtra} = [ ... ];
>
> Additional arguments for a full rsync or rsyncd backup.
>
> The --checksum argument causes the client to send full-file checksum
> for every file (meaning the client reads every file and computes the
> checksum, which is sent with the file list). On the server,
> rsync_bpc will skip any files that have a matching full-file
> checksum, and size, mtime and number of hardlinks. Any file that has
> different attributes will be updating using the block rsync
> algorithm.
>
> In V3, full backups applied the block rsync algorithm to every file,
> which is a lot slower but a bit more conservative. To get that
> behavior, replace --checksum with --ignore-times.
>
> the server may not send any chksum command, but this states that the
> client will anyway use them.
>
> So I'll join  "l, rick" saying that if you deactivate it, your full
> backups will take "a while" - test it, but you won't love it.
>
> Jean-Yves
>
> 
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Re: [BackupPC-users] BPC4: checksum

[Bzzzz]

On Fri, 27 Oct 2017 16:24:51 +0200
B  wrote:

Correction (as often,I read much too fast):

> This i going against: "I don't think so, because on incrementals BPC
> doesn't use "--checksum" at all." (v.4.x doc):

The doc doesn't speak about incrementals (only fulls), but to be sure
about this, you should look at rsync_bpc source.

JY

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Re: [BackupPC-users] BPC4: checksum

[Bzzzz]

On Fri, 27 Oct 2017 12:56:36 +0200
Gandalf Corvotempesta  wrote:

> What happens if I remove "--checksum" from "full" backups ?

Monstrosities:
* an A380 will holographically crash onto your house,
* your dog/cat/children/wife/goldfish will turn gay,
* you'll awake one morning and all your machines will be reinstalled with
  DOS-2.0,
* you'll dream of Bill Gates every night until you pass away,
etc…

and apart that, may be:
http://backuppc.sourceforge.net/faq/BackupPC.html#Rsync-checksum-caching
can help as a base; in v.4.x, there are some light differences:
http://backuppc.sourceforge.net/BackupPC-4.1.3.html

This i going against: "I don't think so, because on incrementals BPC
doesn't use "--checksum" at all." (v.4.x doc):

$Conf{RsyncFullArgsExtra} = [ ... ];

Additional arguments for a full rsync or rsyncd backup.

The --checksum argument causes the client to send full-file checksum
for every file (meaning the client reads every file and computes the
checksum, which is sent with the file list). On the server,
rsync_bpc will skip any files that have a matching full-file
checksum, and size, mtime and number of hardlinks. Any file that has
different attributes will be updating using the block rsync
algorithm.

In V3, full backups applied the block rsync algorithm to every file,
which is a lot slower but a bit more conservative. To get that
behavior, replace --checksum with --ignore-times.

the server may not send any chksum command, but this states that the
client will anyway use them.

So I'll join  "l, rick" saying that if you deactivate it, your full
backups will take "a while" - test it, but you won't love it.

Jean-Yves

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Re: [BackupPC-users] BPC4: checksum

[Gandalf Corvotempesta]

2017-10-27 15:10 GMT+02:00 l, rick :
> As I understand, you will pull all new files, instead of checking time
> stamps and hashing both ends, wasting storage space, as well as putting
> unneeded usage on the network.

I don't think so, because on incrementals BPC doesn't use "--checksum" at all.

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Re: [BackupPC-users] BPC4: checksum

[l, rick]

As I understand, you will pull all new files, instead of checking time 
stamps and hashing both ends, wasting storage space, as well as putting 
unneeded usage on the network.


On 27-10-2017 06:56, Gandalf Corvotempesta wrote:

What happens if I remove "--checksum" from "full" backups ?

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[BackupPC-users] BPC4: checksum

[Gandalf Corvotempesta]

What happens if I remove "--checksum" from "full" backups ?

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