ADSM-L

Re: Windows open file problem

2004-02-26 05:11:44
Subject: Re: Windows open file problem
From: Mario <mario AT NIAGAPRIMA DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 26 Feb 2004 17:17:34 +0700
For the cache location, is drive D:\ is on the same disk with TSM Client?
You should change the cache location to different partition on different
disk...

TSM Open File Support restrictions:
-----------------------------------------------------


1. Microsoft Windows Server 2003.
--------------------------------------------------
Currently OFS is only supported on Windows 2000 and Windows XP.
The current version of OFS support in TSM v5.2.0 does not support Windows
Server 2003. The TSM OFS feature uses its own TSM snapshot technology (TSM
LVSA). Windows Server 2003 has native snapshot support via the Shadow Copy
services, which may prevent the operation of, or negatively interact with
the TSM LVSA. IBM is currently working on removing this restriction so that
OFS will be supported on Windows Server 2003.


2. Machines with a single drive.
----------------------------------------------
OFS uses the TSM LVSA to create a snapshot of a volume that is being backed
up. The TSM LVSA requires the use of a local drive, other than the one that
is being backed up, to contain a cache file. This means the location of this
cache can not be on the same drive that is being backed up. Therefore a
machine with only a single drive can not take advantage of this OFS feature.
IBM is currently working on removing this restriction.


3. Microsoft Terminal Services.
----------------------------------------------
There is known limitation in Microsoft Terminal Services server on Windows
2000 that prevents the OFS feature from working over a Microsoft Terminal
Services session. The following errors are recorded to the dsmerror.log
during the snapshot creation process:
ANS1327E The snapshot operation for 'D:' failed. Error code: 673.
ANS1375E The snapshot operation failed.
ANS1376E Unable to perform operation using a point-in-time copy of the
filesystem. The backup/archive operation will continue without snapshot
support.
To get around this limitation the TSM Remote Web GUI can be used to perform
the backup operation. This limitation does not effect TSM Scheduled backups
which run locally nor will it effect any Restore operations.

The Microsoft Terminal Services limitation can be seen outside of the TSM
Client by logging on to a Terminal Service session and creating a new
volume. Using the Windows Disk Management tool under Administrative Tools
create and format a new volume. The volume is created successfully, but the
new volume will not be seen in Windows Explorer or the Windows Command
Prompt unless the user logs off of the current Terminal Service session and
re-establishes a new Terminal Service session. This limitation is not seen
with the Remote Desktop feature that is included with Windows XP.



Other known OFS issues
-------------------------------------

1. Machines with multiple drives.
-----------------------------------------------
If the OFS feature is selected at Install time (default is not selected)
then the install and setup will place the cache file location
(SNAPSHOTCACHELOCATION option) on the System drive. This will enable OFS
backup for all drives other than the System drive. The backup of the System
drive will detect the cache file on this drive and will place the error
message below in the dsmerror.log and will then fail-over to non-OFS backup
for the System drive.
ANS1327E The snapshot operation for 'C:' failed. Error code: 659.
ANS1228E Sending of object '\\machinename\c$' failed
ANS1381E The snapshot cache location cannot be located on the same volume
that is being backed up.

TSM indicates a failure for the System drive backup since the snapshot could
not occur. This may be a misleading message because the fail-over to non-OFS
will be the same backup support that would be done if the new OFS feature
was not installed. To prevent these error messages use the following option
in the TSM client options file (dsm.opt) to disable OFS on the System drive
(example shown is where C: is the System drive):
"include.fs C: fileleveltype=dynamic"


2. File system IO activity.
------------------------------------
The TSM snapshot feature will wait for a file system to be idle for a given
period to help ensure a consistent point-in-time view of the filesystem.
This is controlled through the SNAPSHOTFSIDLEWAIT and SNAPSHOTFSIDLERETRIES
options. Given that NTFS flushes I/O in bursts, there should be idle time
adequate to take a snapshot between NTFS filesystem cache flushes. TSM also
requests a filesystem flush before a snapshot is taken to further increase
the chance of a consistent filesystem snapshot.

TSM uses a SNAPSHOTFSIDLEWAIT default value of 5 seconds and a
SNAPSHOTFSIDLERETRIES default value of 10. This requires that a period of 5
seconds must pass without write activity (read activity is ignored) on a
volume before a snapshot can occur. If write activity is detected, TSM will
retry again up to 10 times. The values are conservatively set to maximize
the chances of a consistent point-in-time state of the filesystem. Although
a value of 5 seconds may seem high, most backups will be scheduled during
low user and filesystem activity time (for example overnight). This, with
the retries, should allow for a successful snapshot to occur.

Any temporary burst of write activity (for example a very large file
download) should be overcome by the retries or during the next scheduled
backup. However, the following errors may occur if persistent I/O activity
is seen on the drive:
ANS1327E The snapshot operation for 'objectname' failed. Error code: 672
ANS1380E The snapshot operation failed. The filesystem write activity
prevented the Logical Volume Snapshot Agent from satisfying the
SNAPSHOTFSIDLEWait and SNAPSHOTFSIDLERetries options.
ANS1376E Unable to perform operation using a point-in-time copy of the
filesystem. The backup/ archive operation will continue without snapshot
support.

If this I/O activity is persistent, and the snapshot attempts are failing,
then it is recommended that the SNAPSHOTFSIDLERETRIES be increased (for
example 20) and/or the SNAPSHOTFSIDLEWAIT lowered (for example 2, 1 or 500ms
which would wait 2 seconds, 1 second, and .5 seconds, respectively). Values
less than 5 seconds are considered acceptable for TSM File level backup. IBM
does not recommend a value of 0

If adjusting the SNAPSHOTFSIDLEWAIT and SNAPSHOTFSIDLERETRIES values still
do not allow a snapshot to take place, this may indicate that an application
is using that file for sustained I/O operations (for example a database
product recovery log file). In this case database consistency may be an
issue and it is advised that the pre and post snapshotmcd options be used to
notify the application to suspend I/O while the snapshot is taking place.
The snapshot should occur in a very short amount of time, so the delay
between the PRESNAPSHOTCMD and POSTSNAPSHOTCMD is only the time to establish
the snapshot and not the entire backup. The PRESCHEDULECMD/POSTSCHEDULECMD
can also be used to avoid the need for OFS support if the application can be
brought down during the length of time needed for the backup.

OFS related options
------------------------------------
The following options can be set for all volumes or can be set per volume
using the INCLUDE.FS option:
SNAPSHOTCACHELOCATION, SNAPSHOTCACHESIZE, SNAPSHOTFSIDLERETRIES,
SNAPSHOTFSIDLEWAIT, PRESNAPSHOTCMD, POSTSNAPSHOTCMD


----- Original Message -----
From: "TSM_User" <tsm_user AT YAHOO DOT COM>
To: <ADSM-L AT VM.MARIST DOT EDU>
Sent: Thursday, February 26, 2004 4:29 AM
Subject: Re: Windows open file problem


> To eliminate this error I believe you could add the following to your
dsm.opt file.
> include.fs C: fileleveltype=dynamic
>
>
> Someone at Tivoli wrote a great tech doc that gives a lot of details on
open file support.
>
http://www-1.ibm.com/support/docview.wss?rs=203&q1=snapshot+cache+location&u
id=swg21121552&loc=en_US&cs=utf-8&lang=en+en
>
> If the link doesn't work then go to www.ibm.com/software/support.  Search
for "TSM Client v5.2 Open File Support".
>
> Peter Daransky <Peter.Daransky AT AMBOS DOT AT> wrote:
> Hi,
> i'm trying to backup a Windows machine with open file support with TSM
> V5.2.2.0 . But i got always this error
>
> ANS1228E Sending of object '\\host\c$' failed
> ANS1381E The snapshot cache location cannot be located on the same
> volume that is being backup up.
>
> Of course tha cache is on D:\ located ?!
> I've seen that the same problem was here in discussion yet. Has someone
> solve this problem ?
>
> Regards
>
> Peter Daransky
> AMBOS EDV-Beratungs GesmbH
> Dauphinestr. 44
> A-4020 LINZ Austria
> Tel: +43-732-312919-0
> Fax: +43-732-312919-20
> e-mail: Peter.Daransky AT ambos DOT at
> Homepage: http://www.ambos.at
>
> ---------------------------------
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