zfs discuss - Jan 2009 - ZFS iscsi snapshot - VSS compatible?

Hi all,

If I want to make a snapshot of an iscsi volume while there''s a
transfer going on, is there a way to detect this and either 1) not include the
file being transferred, or 2) wait until the transfer is finished before making
the snapshot?

If I understand correctly, this is what Microsoft''s VSS is supposed to
do. Am I right?

Right now, when there is a transfer going on while making the snapshot, I always
end up with a corrupt file (understandably so, since the file transfer is
unfinished).

S

Since iSCSI is block-level, I don''t think the iSCSI intelligence at
the file level you''re asking for is feasible. VSS is used at the
file-system level on either NTFS partitions or over CIFS.

-J

On Wed, Jan 7, 2009 at 5:06 PM, Mr Stephen Yum <sosurim at yahoo.com>
wrote:
> Hi all,
>
> If I want to make a snapshot of an iscsi volume while there''s a
transfer going on, is there a way to detect this and either 1) not include the
file being transferred, or 2) wait until the transfer is finished before making
the snapshot?
>
> If I understand correctly, this is what Microsoft''s VSS is
supposed to do. Am I right?
>
> Right now, when there is a transfer going on while making the snapshot, I
always end up with a corrupt file (understandably so, since the file transfer is
unfinished).
>
> S
>
>
>
>
>
> _______________________________________________
> storage-discuss mailing list
> storage-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/storage-discuss
>

OMG, no safety feature?!
Sorry, even on ZFS turf,
if you use HyperV, and the HyperV VSS Writer, it could be a lot safer
-- if you don''t know how to do a block-level Super thing...

best,
zStorageAnalyst

----- Original Message ----- 
From: "Jason J. W. Williams" <jasonjwwilliams at gmail.com>
To: "Mr Stephen Yum" <sosurim at yahoo.com>
Cc: <zfs-discuss at opensolaris.org>; <storage-discuss at
opensolaris.org>
Sent: Wednesday, January 07, 2009 7:30 PM
Subject: Re: [zfs-discuss] [storage-discuss] ZFS iscsi snapshot - 
VSScompatible?

> Since iSCSI is block-level, I don''t think the iSCSI intelligence
at
> the file level you''re asking for is feasible. VSS is used at the
> file-system level on either NTFS partitions or over CIFS.
>
> -J
>
> On Wed, Jan 7, 2009 at 5:06 PM, Mr Stephen Yum <sosurim at yahoo.com>
wrote:
>> Hi all,
>>
>> If I want to make a snapshot of an iscsi volume while there''s
a transfer
>> going on, is there a way to detect this and either 1) not include the 
>> file being transferred, or 2) wait until the transfer is finished
before
>> making the snapshot?
>>
>> If I understand correctly, this is what Microsoft''s VSS is
supposed to
>> do. Am I right?
>>
>> Right now, when there is a transfer going on while making the snapshot,
I
>> always end up with a corrupt file (understandably so, since the file 
>> transfer is unfinished).
>>
>> S
>>
>>
>>
>>
>>
>> _______________________________________________
>> storage-discuss mailing list
>> storage-discuss at opensolaris.org
>> http://mail.opensolaris.org/mailman/listinfo/storage-discuss
>>
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

On Wed, Jan 7, 2009 at 6:30 PM, Jason J. W. Williams <
jasonjwwilliams at gmail.com> wrote:
> Since iSCSI is block-level, I don''t think the iSCSI intelligence
at
> the file level you''re asking for is feasible. VSS is used at the
> file-system level on either NTFS partitions or over CIFS.
>
> -J


VSS integration with block protocols is most definitely possible.  It just
requires *intelligent* software running on the host side.  That intelligence
would likely need to come from Sun directly in the case of windows on raw
hardware as I don''t know of any third party apps that work universally
with
any storage system.

--Tim
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Okay, so is there an implementation of HyperV or VSS or whatever on the
Solaris+ZFS environment?

Also, is there something like this if I were to access ZFS-based storage from a
Linux client, for example?

Since most of my clients will be running some version of Windows while accessing
a ZFS backend array through a Windows 2003 or Windows 2008 server, just a
solution that can mimic HyperV or VSS would be great.

Thanks so much in advance

S



----- Original Message ----
From: JZ <jz at excelsioritsolutions.com>
To: Jason J. W. Williams <jasonjwwilliams at gmail.com>; Mr Stephen Yum
<sosurim at yahoo.com>
Cc: zfs-discuss at opensolaris.org; Tim <tim at tcsac.net>
Sent: Wednesday, January 7, 2009 4:45:05 PM
Subject: Re: [zfs-discuss] [storage-discuss] ZFS iscsi snapshot - VSScompatible?

OMG, no safety feature?!
Sorry, even on ZFS turf,
if you use HyperV, and the HyperV VSS Writer, it could be a lot safer
-- if you don''t know how to do a block-level Super thing...

best,
zStorageAnalyst

----- Original Message ----- From: "Jason J. W. Williams"
<jasonjwwilliams at gmail.com>
To: "Mr Stephen Yum" <sosurim at yahoo.com>
Cc: <zfs-discuss at opensolaris.org>; <storage-discuss at
opensolaris.org>
Sent: Wednesday, January 07, 2009 7:30 PM
Subject: Re: [zfs-discuss] [storage-discuss] ZFS iscsi snapshot - VSScompatible?

> Since iSCSI is block-level, I don''t think the iSCSI intelligence
at
> the file level you''re asking for is feasible. VSS is used at the
> file-system level on either NTFS partitions or over CIFS.
> 
> -J
> 
> On Wed, Jan 7, 2009 at 5:06 PM, Mr Stephen Yum <sosurim at yahoo.com>
wrote:
>> Hi all,
>> 
>> If I want to make a snapshot of an iscsi volume while there''s
a transfer going on, is there a way to detect this and either 1) not include the
file being transferred, or 2) wait until the transfer is finished before making
the snapshot?
>> 
>> If I understand correctly, this is what Microsoft''s VSS is
supposed to do. Am I right?
>> 
>> Right now, when there is a transfer going on while making the snapshot,
I always end up with a corrupt file (understandably so, since the file transfer
is unfinished).
>> 
>> S
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> storage-discuss mailing list
>> storage-discuss at opensolaris.org
>> http://mail.opensolaris.org/mailman/listinfo/storage-discuss
>> 
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss