Tobia's questions

I'm working on a new nas to store veeam backups of some VMs.

I will use some magnetic disks and my doubt is about optional ssd cache disks.

I was wondering if it is important the cache layer, generally I know few cache disks is not a bad idea, but in this case I would like to know if it is recommended or not very useful.

As far as I know the cache is used to absorb few small operations or repeated operations in same sectors. In a vm backup scenario I expect a massive write ops and cache layer will be shortly filled and became almost unuseful.

Am I right or am I wrong?

I'm configuring a MS 365 Hybrid deployment, MX will be keeped to Exchange on premise server.

I have a On premise antispam (LibraEsva) that I don't want to remove.

This is the actual configuration:

Following MS guide lines, the connection between Exchange On Premise and Cloud has to be direct without any filter.

As you can see the there is a SMTP 25 from public internet to MX interface filtered by Antispam. Moreover, there is another SMTP 25 connection between Exchange On Premise and Cloude for internal routing between local and cloud mailboxed.

I made 2 NAT

• From Any with port SMTP-25 forwarded to Antispam
• From MS365 ips with port SMTP-25 forwarded to Exchange

This works, public email are filtered, and email between Exchange server are not filtered...

BUT

The NAT made from MS365 hostname are getting all public emails from MS 365 NOT ONLY the internal ones, if any user of 365 sends an email to me, it is not filtered anymore.

How can I solve this brain teaser? I think there should be a solution.

I want to create a remote repository for the backup of my local infrastructure. I'm using Veeam v10.

I think I need a remote machine with a Veeam component installed, then I was wondering if I can build a EC2 Windows machine with Veeam with S3 as storage.

The goal is to transfer from my site to EC2 only the incremental backup (I cannot transfer a full with my bandwith!) and let the machine compute and merge backup in a reverse incremental backup. Is this a good configuration? Is it possibile to use EC2 with a S3 storage for veeam repository?

I have to set a persistent custom SQL MODE persistent to my server. I added this line in /etc/mysql/mysql.conf.d/mysqld.cnf

[mysqld]
...
sql-mode = STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

When I try to run mysql I get this error:

2020-06-03T09:49:24.567568Z 0 [ERROR] [MY-000077] [Server] /usr/sbin/mysqld: Error while setting value 'STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION' to 'sql_mode'. mysqld Ver 8.0.20-0ubuntu0.20.04.1 for Linux on x86_64 ((Ubuntu))

I tried to change sql-mode to sql_mode and remove the double quotes, but it doesn't change.

I have two WAN from different providers, I would like to know how can I manage an IP failover to switch services in case of failur of the primary WAN. The only solution that I know is to use dns records and switch them in case of failure.

• Is there any service to switch them automatically?
• If I set a low TTL for my dns records can I be sure a fast switch from clients all over the world? Do DNS cache servers consider my TTL settings?

I had to change a drive in my IBM DS3512 SAN, I bought it by model (Seagate model) and not by IBM FRU code. I tried to put the drive but it fails with error "incompatible drive". I saw that the model is really the same of other drives but firmware version and manufacturer name is different.

Probably I have to give the drive back and look for the FRU part, but firstly I want to know if is there any way to override this problem, maybe flashing the IBM firmware in the drive.

This SAN is not in production enviroment but only for testing

My primary WIN 2012 VM domain controller cannot update anymore, every update fails with this error:

Windows failed to install the following update with error 0x800f0900

I tried many things:

• reset SoftwareDistribution directory
• sfc /scannow ends without errors
• dism /online /cleanup-image /restorehealth stucks at 40% (I wait 18hours, then I stoped it)
• dism /online /cleanup-image /source.... /restorehealth get from a DVD source stucks at 40% like the previous
• clean and secure boot before previous commands

What can I try to do?

**** EDIT WindowsUpdate.log content:

2017-01-17  22:33:14:450     920    ff4 Handler Generating request for CBS update 641FE631-29F1-46B4-BBED-7D2B8D56741B in sandbox C:\Windows\SoftwareDistribution\Download\61d75607e4a6a41d2d6d304bed92af67
2017-01-17  22:33:14:529     920    ff4 Handler Selected payload type is ptExpress
2017-01-17  22:33:14:607     920    ff4 Handler UH: DpxRestoreJob returned 0x80070002
2017-01-17  22:33:14:607     920    ff4 Handler Detected download state is dsHavePackage
2017-01-17  22:33:30:935     920    364 Handler FATAL: CBS called Error with 0x800f0900, 
2017-01-17  22:33:30:951     920    ff4 Handler FATAL: UH: 0x800f0900: Async stage operation failed in CUHCbsHandler::StageCbsPackage
2017-01-17  22:33:31:107     920    ff4 Handler FATAL: Request generation for CBS update complete with hr=0x800f0900 and pfResetSandbox=0 
2017-01-17  22:33:31:107     920    ff4 Handler FATAL: Error source is 106.
2017-01-17  22:33:31:107     920    ff4 DnldMgr FATAL: DM:CAgentDownloadManager::GenerateAllDownloadRequests: GenerateDownloadRequest failed with 0x800f0900.
2017-01-17  22:33:32:404     920    ff4 DnldMgr WARNING: Download request generation failed with 0x800f0900.
2017-01-17  22:33:32:435     920    ff4 DnldMgr Error 0x800f0900 occurred while downloading update; notifying dependent calls.
2017-01-17  22:33:32:466     920    174 AU  >>##  RESUMED  ## AU: Download update [UpdateId = {4485F552-0451-4646-B224-BEC7507523F3}]
2017-01-17  22:33:32:466     920    174 AU    # WARNING: Download failed, error = 0x800F0900
2017-01-17  22:33:32:779     920    174 AU  #########
2017-01-17  22:33:32:779     920    174 AU  ##  END  ##  AU: Download updates
2017-01-17  22:33:32:779     920    174 AU  #############

CBS log:

2017-01-27 17:11:26, Info                  CBS    Exec: Package: Package_20_for_KB2934016~31bf3856ad364e35~amd64~~6.2.1.1 is already in the correct state, current: Installed, targeted: Installed
2017-01-27 17:11:26, Info                  CBS    Exec: Skipping Package: Package_20_for_KB2934016~31bf3856ad364e35~amd64~~6.2.1.1, Update: 2934016-60_neutral_LDR because it is already in the correct state.
2017-01-27 17:11:26, Info                  CBS    Exec: Skipping Package: Package_20_for_KB2934016~31bf3856ad364e35~amd64~~6.2.1.1, Update: 2934016-61_neutral_LDR because it is already in the correct state.
2017-01-27 17:11:26, Info                  CBS    Exec: Skipping Package: Package_20_for_KB2934016~31bf3856ad364e35~amd64~~6.2.1.1, Update: 2934016-62_neutral_GDR because it is already in the correct state.
2017-01-27 17:11:26, Info                  CBS    Failed to peek next token (status=0xc0000161) [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Failed to get next Token [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Wrong XML DECL [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Invalid xml format [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Manifest parsing error at line: 1, context: 
 [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Failed to parse the manifest from the buffer. [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Error                 CBS    Failed to parse package manifest: \\?\C:\Windows\Servicing\Packages\Package_357_for_KB2836988~31bf3856ad364e35~amd64~~6.2.1.0.mum [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Mark store corruption flag because of parsing failure on package: Package_357_for_KB2836988~31bf3856ad364e35~amd64~~6.2.1.0. [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Failed to initialize package: Package_357_for_KB2836988~31bf3856ad364e35~amd64~~6.2.1.0, from path: \\?\C:\Windows\Servicing\Packages\Package_357_for_KB2836988~31bf3856ad364e35~amd64~~6.2.1.0.mum, existing package: 1 [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Mark store corruption flag because of package: Package_357_for_KB2836988~31bf3856ad364e35~amd64~~6.2.1.0. [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Failed to resolve package [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Failed to get next package to re-evaluate [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Failed to process component watch list. [HRESULT = 0x800f0900 - CBS_E_XML_PARSER_FAILURE]
2017-01-27 17:11:26, Info                  CBS    Perf: InstallUninstallChain complete.
2017-01-27 17:11:26, Info                  CSI    00000b91@2017/1/27:16:11:26.555 CSI Transaction @0x6db95b2ce0 destroyed
2017-01-27 17:11:26, Info                  CBS    Exec: Store corruption found during execution, but auto repair is already attempted today, skip it.

Today I got many spammy emails into my mailbox, I looked in exim4 logs and I found some suspected activities.

I would like to understand the serverity of this attack, if I got spammy mail I can delete them and add some rules, however I want to be sure that I'm not a spammer.

I read many of these logs:

  2016-03-09 07:53:12 1adXzZ-0007sb-Pz <= [email protected] H=([127.0.0.1]) [129.137.152.170] P=esmtpa A=plain: S=1298 [email protected]
  2016-03-09 07:53:12 1adXzZ-0007sb-Pz no immediate delivery: more than 10 messages received in one connection
  2016-03-09 08:16:57 1adXzZ-0007sb-Pz => kamikaze_****@hotmail.co.uk R=dnslookup T=remote_smtp H=mx3.hotmail.com [207.46.8.167] X=TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256 CV=no DN="CN=*.hotmail.com" C="250  <[email protected]> Queued mail for delivery"
  2016-03-09 08:16:57 1adXzZ-0007sb-Pz Completed

Please consider that:

• kamikaze_****@hotmail.co.uk (I add some asterisks for privacy) is not a known recipient and this is not a mailbox in my server.
• Realy should be permitted only to authenticated users, and here I did not find any authentication info.
• In the log there is a 250 and "Completed", so seems that no error was thrown. The sign of the log is "=>" that means outgoing message...

So, I'm a spammer? Is my server sending mails without authentication?

This is my configuration:

accept_8bitmime
acl_smtp_data = acl_check_data
acl_smtp_data_prdr = accept
acl_smtp_mail = acl_check_mail
acl_smtp_rcpt = acl_check_rcpt
admin_groups =
no_allow_domain_literals
no_allow_mx_to_ip
no_allow_utf8_domains
auth_advertise_hosts = *
auto_thaw = 0s
av_scanner = sophie:/var/run/sophie
bounce_return_body
bounce_return_message
bounce_return_size_limit = 100K
callout_domain_negative_expire = 3h
callout_domain_positive_expire = 1w
callout_negative_expire = 2h
callout_positive_expire = 1d
callout_random_local_part = $primary_hostname-$tod_epoch-testing
check_log_inodes = 0
check_log_space = 0
check_rfc2047_length
check_spool_inodes = 0
check_spool_space = 0
daemon_smtp_ports = smtp
daemon_startup_retries = 9
daemon_startup_sleep = 30s
delay_warning = 1d
delay_warning_condition = ${if or {{ !eq{$h_list-id:$h_list-post:$h_list-subscribe:}{} }{ match{$h_precedence:}{(?i)bulk|list|junk} }{ match{$h_auto-submitted:}{(?i)auto-generated|auto-replied} }} {no}{yes}}
no_deliver_drop_privilege
deliver_queue_load_max =
delivery_date_remove
no_disable_ipv6
dkim_verify_signers = $dkim_signers
dns_check_names_pattern = (?i)^(?>(?(1)\.|())[^\W](?>[a-z0-9/_-]*[^\W])?)+(\.?)$
dns_csa_search_limit = 5
dns_csa_use_reverse
dns_dnssec_ok = -1
dns_retrans = 0s
dns_retry = 0
dns_use_edns0 = -1
no_drop_cr
dsn_from = Mail Delivery System <Mailer-Daemon@$qualify_domain>
envelope_to_remove
exim_group = Debian-exim
exim_path = /usr/sbin/exim4
exim_user = Debian-exim
extract_addresses_remove_arguments
finduser_retries = 0
freeze_tell = postmaster
gecos_name = $1
gecos_pattern = ^([^,:]*)
no_gnutls_allow_auto_pkcs11
no_gnutls_compat_mode
header_line_maxsize = 0
header_maxsize = 1048576
headers_charset = UTF-8
helo_allow_chars = _
helo_lookup_domains = @ : @[]
host_lookup = *
host_lookup_order = bydns:byaddr
ignore_bounce_errors_after = 2d
no_ignore_fromline_local
keep_malformed = 4d
no_ldap_start_tls
ldap_version = -1
no_local_from_check
local_interfaces = <; ::0 ; 0.0.0.0
local_scan_timeout = 5m
local_sender_retain
log_file_path = /var/log/exim4/%slog
log_selector = +smtp_protocol_error +smtp_syntax_error +tls_certificate_verified +tls_peerdn
no_log_timezone
lookup_open_max = 25
max_username_length = 0
no_message_body_newlines
message_body_visible = 500
message_logs
message_size_limit = 50M
no_move_frozen_messages
no_mua_wrapper
mysql_servers = localhost/system/exim/mypassw
never_users =
no_perl_at_start
pid_file_path = /var/run/exim4/exim.pid
pipelining_advertise_hosts = *
prdr_enable
no_preserve_message_logs
primary_hostname = srv1.mydomain.com
no_print_topbitchars
process_log_path = /var/spool/exim4/exim-process.info
prod_requires_admin
qualify_domain = mydomain.com
qualify_recipient = mydomain.com
queue_list_requires_admin
no_queue_only
queue_only_load =
queue_only_load_latch
queue_only_override
no_queue_run_in_order
queue_run_max = 5
receive_timeout = 0s
received_header_text = Received: ${if def:sender_rcvhost {from $sender_rcvhost\n\t}{${if def:sender_ident {from ${quote_local_part:$sender_ident} }}${if def:sender_helo_name {(helo=$sender_helo_name)\n\t}}}}by $primary_hostname ${if def:received_protocol {with $received_protocol}} ${if def:tls_cipher {($tls_cipher)\n\t}}(Exim $version_number)\n\t${if def:sender_address {(envelope-from <$sender_address>)\n\t}}id $message_exim_id${if def:received_for {\n\tfor $received_for}}
received_headers_max = 30
recipients_max = 0
no_recipients_max_reject
remote_max_parallel = 2
retry_data_expire = 1w
retry_interval_max = 1d
return_path_remove
rfc1413_hosts = @[]
rfc1413_query_timeout = 0s
slow_lookup_log = 0
smtp_accept_keepalive
smtp_accept_max = 20
smtp_accept_max_nonmail = 10
smtp_accept_max_nonmail_hosts = *
smtp_accept_max_per_connection = 1000
smtp_accept_queue = 0
smtp_accept_queue_per_connection = 10
smtp_accept_reserve = 0
smtp_banner = $smtp_active_hostname ESMTP Exim $version_number Ubuntu $tod_full
smtp_check_spool_space
smtp_connect_backlog = 20
smtp_enforce_sync
smtp_etrn_serialize
smtp_load_reserve =
smtp_max_synprot_errors = 3
smtp_max_unknown_commands = 3
no_smtp_return_error_details
spamd_address = 127.0.0.1 783
no_split_spool_directory
spool_directory = /var/spool/exim4
sqlite_lock_timeout = 5
no_strict_acl_vars
no_strip_excess_angle_brackets
no_strip_trailing_dot
syslog_duplication
syslog_processname = exim
syslog_timestamp
tcp_nodelay
timeout_frozen_after = 1w
tls_advertise_hosts = *
tls_certificate = /etc/exim4/exim.crt
tls_dh_max_bits = 2236
tls_eccurve = prime256v1
tls_on_connect_ports = 465
tls_privatekey = /etc/exim4/exim.key
no_tls_remember_esmtp
tls_verify_certificates = ${if exists{/etc/ssl/certs/ca-certificates.crt}{/etc/ssl/certs/ca-certificates.crt}{/dev/null}}
trusted_groups =
trusted_users = uucp
untrusted_set_sender = *
uucp_from_pattern = ^From\s+(\S+)\s+(?:[a-zA-Z]{3},?\s+)?(?:[a-zA-Z]{3}\s+\d?\d|\d?\d\s+[a-zA-Z]{3}\s+\d\d(?:\d\d)?)\s+\d\d?:\d\d?
uucp_from_sender = $1
write_rejectlog

And this is the PLAIN authenticator:

plain:
driver                          = plaintext
public_name                     = PLAIN
server_advertise_condition      = yes
server_condition                = ${if eq{$3}{${lookup mysql{ SELECT password FROM users WHERE CONCAT(username,'@',domain)='${quote_mysql:$2}' AND smtp>0 }}}{yes}{no}}
server_set_id                   = $2

This is the today exim reject log:

2016-01-07 13:48:44 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 15:32:09 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 15:41:35 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 15:49:01 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 15:56:50 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:04:58 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:12:28 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:20:19 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:28:08 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:35:50 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:43:28 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:51:18 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 16:58:51 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:06:25 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:13:58 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:21:29 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:28:52 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:36:18 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:43:43 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:51:46 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 17:59:08 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:06:44 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:14:10 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:21:39 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:29:02 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:36:36 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:44:00 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:51:21 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 18:58:40 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:05:59 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:13:18 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:20:42 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:28:03 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:35:48 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:43:11 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:50:35 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 19:57:59 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 20:05:25 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 20:12:51 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 20:20:17 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 20:27:41 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])
2016-01-07 20:35:06 login authenticator failed for (USER) [212.224.87.119]: 535 Incorrect authentication data ([email protected])

I don't want to wait and do nothing more, is it possibile to create a blacklist for exim populated with ip addresses of more then 10 login attemps in 1h?

Mind that I want to creare a blacklist for smtp login attemps and not for email senders.

This is a question about MX procotol priority. If I have two server as MX with different priority:

• MX 10 serverA
• MX 20 serverB

Is this guarantee by the protocol that the MX 10 is the prefered? Can the submitter choose the secondary for any other reason but primary availability?

In other words: if my serverA MX is well working and with (theoretical) infinite connection capacity, can I be sure that nobody will try a connection to serverB?

I have an error from a Veeam Hyper-V backup of a Virtual Machine in a Hyper-V host:

Unable to create snapshot (Microsoft CSV Shadow Copy Provider) (mode: Veeam application-aware processing). Details: Writer 'Microsoft Hyper-V VSS Writer' is failed at 'VSS_WS_FAILED_AT_POST_SNAPSHOT'. The writer experienced a transient error. If the backup process is retried, the error may not reoccur. --tr:Failed to verify writers state. --tr:Failed to create VSS snapshot. --tr:Failed to perform pre-backup tasks.

I cannot understand if this is a host error, a guest error or Veeam error. I tried to reboot the VM but I got the same error. I did not try to reboot the host, but I tried to change the host (this VM is inside a failover cluster of two hosts) and with this change the backup works again.

During the backup failure I ran this command in the host:

 vssadmin list writers

The output was:

>    Writer name: 'Microsoft Hyper-V VSS Writer'
>        Writer Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
>        Writer Instance Id: {f50fe40b-27d6-4a98-8713-e5a1dce54c97}
>        State: [1] Frozen

After the VM migrates to another host, the writer state changes back to "Stable".

What can freeze the VSS writers?

There is a 10103 event in the Host:

Failed to revert to VSS snapshot on the virtual hard disk '\\?\Volume{29e16157-002f-4cb4-af58-c95acbd54be9}\' of the virtual machine 'srvshare1'.

In my domain there are two domain controllers, there is a gap of 3 minutes between their times and than I can find this difference between many clients (it depends on their DC).

If I run this command:

w32tm /monitor

I can see that DCs can see each other's time. But if I run this command:

w32tm /resync

Nothing changes, can you tell me why?

EDIT

This is my test output from the secondary DC:

PS C:\Users\administrator.MYDOMAIN> w32tm /config /syncfromflags:DOMHIER /update
The command completed successfully.
PS C:\Users\administrator.MYDOMAIN> w32tm /resync /nowait /rediscover
Sending resync command to local computer
The command completed successfully.
PS C:\Users\administrator.MYDOMAIN> w32tm /monitor
SRVDC1.MYDOMAIN.locale *** PDC ***[10.0.0.10:123]:
    ICMP: 0ms delay
    NTP: +0.0000000s offset from SRVDC1.MYDOMAIN.locale
        RefID: ntp.ngi.it [88.149.128.123]
        Stratum: 3
SRVDC2.MYDOMAIN.locale[[fe80::c5ec:8a39:e860:e2e7%13]:123]:
    ICMP: 0ms delay
    NTP: -146.4122820s offset from SRVDC1.MYDOMAIN.locale
        RefID: 80.84.77.86.rev.sfr.net [86.77.84.80]
        Stratum: 2

Warning:
Reverse name resolution is best effort. It may not be
correct since RefID field in time packets differs across
NTP implementations and may not be using IP addresses.
PS C:\Users\administrator.MYDOMAIN>

After 15 minutes, the time gap is still there.

This is the query status command output (seems that the sync is working):

PS C:\Users\administrator.MYDOMAIN> w32tm /query /status /verbose
Leap Indicator: 0(no warning)
Stratum: 2 (secondary reference - syncd by (S)NTP)
Precision: -6 (15.625ms per tick)
Root Delay: 0.0000000s
Root Dispersion: 0.0100000s
ReferenceId: 0x564D5450 (source IP:  86.77.84.80)
Last Successful Sync Time: 28/08/2014 08.52.00
Source: VM IC Time Synchronization Provider
Poll Interval: 6 (64s)

Phase Offset: 0.0051939s
ClockRate: 0.0156215s
State Machine: 2 (Sync)
Time Source Flags: 3 (Authenticated Hardware )
Server Role: 64 (Time Service)
Last Sync Error: 0 (The command completed successfully.)
Time since Last Good Sync Time: 3.3291425s

I don't know if it is important, but DC1 and DC2 are Virtual Machines in two different servers.

I need to add an user to local administrators of all machines in domain. I read about Restricted Groups, however I don't want to replace all members, but just append a new one. Is it possibile?

When I create a new folder in a shared folder under Windows Server 2012 sometimes i can not see new folder by windows 7 clients. Also with some refresh I still can not see new folders. After some minutes they appear. Is possibile to change the refresh time or what can be?

thank you

I have two computer, the first one is the server (so WinXP) with a shared folder granted for user "test" and this is out of domain, it is just in WORKGROUP. The second computer is a client computer (WS2012) in domain and i would like to access directly to the shared folder of the server without prompting username/password.

I tried to add a "test" user (with the same password) in localuser of the client and also in the domain, but the access fails.

I need this on.the.fly access because i need some file from share just with a file path (ex. \server\path\file.txt) without prompting.

thank you.

I need a command (like "dir") that lists all directories with their size. I need just a 1 level deepness but with the total size of a directory.

For example

>dirsize c:/mainfolder
    subfolder1  15640
    subfolder2 682310
    subfolder3 283550

I installed Debian with kernel 2.6.32-5-686 on a Hyper-V virtual machine. I had to add a legacy network card. I follow this tutorial http://www.yusufozturk.info/linux-server/debian-2-6-36-kernel-upgrade-for-hyper-v-client-drivers.html to add Hyper-V driver but when I reboot with the new kernel i got this error:

BLKVSC_DRV: blkvsc_probe() ERROR!! register_blkdev() failed! ret -16

And at the very first boot log (that i can not copy because i did not find it in dmesg or boot log) i see a mount /dev error.

Thank you.

I'm trying to link a debian server authentication to active directory. I followed this tutorial: http://wiki.debian.org/Authenticating_Linux_With_Active_Directory but I'm stuck on the

getent passwd

Because this doesn't list all AD users but only locals. This is my nsswitch.conf:

passwd:         files winbind
group:          files winbind
shadow:         files winbind

And I'm sure it is well connected to AD becuse this:

wbinfo -u

Lists all AD users. What have I missed?

Do you know if exists something like "alias" for domain users? On my domain I have a short username (ex. n.surname) and i would like users could login with extended name (es. name.surname) to the same profile. Is it possibile?

Thanks

I would like to find all unused accounts of the active directory, so I need to see the last access to the domain. I looked into the user properties but I did not find anything. Where can I find this information?