iSCSI Initiator - New Files Not Being Displayed
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Wednesday, December 05, 2012 3:11 AM
I have two LUNs on my NAS that are configured for iSCSI. I have three Windows Server 2008 R2 servers that connect to these LUNs - one as read/write, the other two as read-only (both of these are using the Microsoft iSCSI Initiator). SERVER1, my Veeam Backup and Replication server, has read/write access and uses the LUNs to store my .vbk and .vib files. SERVER2, my Backup Exec 2010 server, has read-only access and is used to write the .vbk files to tape. SERVER3 also has read-only access and I'm trying to use it as my replication server (currently this work is done using cwRsync on SERVER1, but I'd like to offload this work).
The problem is that SERVER3 doesn't seem to see any of the new backup files that are created by SERVER1 unless I reboot SERVER3 (SERVER2 sees the new files without issue). Since rebooting my server before every replication isn't really an option, what else can I check that I might have missed?
Thank you!
All Replies
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Wednesday, December 05, 2012 11:33 AM
I have two LUNs on my NAS that are configured for iSCSI. I have three Windows Server 2008 R2 servers that connect to these LUNs - one as read/write, the other two as read-only (both of these are using the Microsoft iSCSI Initiator). SERVER1, my Veeam Backup and Replication server, has read/write access and uses the LUNs to store my .vbk and .vib files. SERVER2, my Backup Exec 2010 server, has read-only access and is used to write the .vbk files to tape. SERVER3 also has read-only access and I'm trying to use it as my replication server (currently this work is done using cwRsync on SERVER1, but I'd like to offload this work).
The problem is that SERVER3 doesn't seem to see any of the new backup files that are created by SERVER1 unless I reboot SERVER3 (SERVER2 sees the new files without issue). Since rebooting my server before every replication isn't really an option, what else can I check that I might have missed?
Thank you!
Well... The problem is you're using SAN in the way it does not work. Making long story short you need either SAN-aware file system (MelioFS from Sanbolic, SFS from DataPlow of Blue Whale FS from China newcomers) or distributed lock manager like SANmp from SNS or MetaSAN from Tiger Technoligies together with non-SAN-aware FS (like NTFS). See, there's nobody on other nodes having clue about LUN reservation so you'll simply damage $MFT with concurrent writes. See this thread (it's on StarWind forum but the issue is the same for any SAN, iSCSI or FC or FCoE does not matter):
The most stright-forward way for you to go - configure NAS share (SMB or NFS does not matter) on top of SAN and use this NAS gateway to access your SAN content. As all of the referenced solutions are paid and not cheap. And make sense for a very limited use cases (usually non-compressed video content editing). If it's close to your case (which I doubt...) you maybe want to look at iSCSI target pioneers who have solid solution for both block and file level access:
Hope this helped :)
- Marked As Answer by Cheers ZHANGMicrosoft Contingent Staff, Moderator Tuesday, December 11, 2012 6:58 AM
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Wednesday, December 05, 2012 12:55 PMThank you for the reply. I am aware of the potential issues with having more than one target writing to my SAN which is why there is (and will only be) one server with read/write and the rest having read-only. As I said, what I'm looking to accomplish works with SERVER1 and SERVER2, but SERVER3 doesn't seem to be refreshing (for lack of a better word) unless I reboot.
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Wednesday, December 05, 2012 5:20 PM
Thank you for the reply. I am aware of the potential issues with having more than one target writing to my SAN which is why there is (and will only be) one server with read/write and the rest having read-only. As I said, what I'm looking to accomplish works with SERVER1 and SERVER2, but SERVER3 doesn't seem to be refreshing (for lack of a better word) unless I reboot.
It's the same. Nobody told him block device he "sees" was updated by somebody else. So the only thing you can have is if everybody has read-only access. Or use mount-unmount sequence. See how MS iSCSI initiator can be scripted:
http://technet.microsoft.com/en-us/library/hh826099.aspx
http://blogs.msdn.com/b/san/archive/2012/07/31/managing-iscsi-initiator-connections-with-windows-powershell-on-windows-server-2012.aspx
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Wednesday, December 05, 2012 5:27 PMI guess what I'm trying to understand is what's different between SERVER2 and SERVER3 that causes SERVER3 to not see the new files? Both are running Server 2008 R2, both are using the Microsoft iSCSI Initiator, but only SERVER2 sees the files. I will add that SERVER2 is physical and SERVER3 is virtual, but they're both using the same OS and software to connect to my SAN.
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Wednesday, December 05, 2012 6:58 PM
Unfortunately, these pages apply to Windows Server 2012, but I'm only running 2008 R2.See how MS iSCSI initiator can be scripted:
http://technet.microsoft.com/en-us/library/hh826099.aspx
http://blogs.msdn.com/b/san/archive/2012/07/31/managing-iscsi-initiator-connections-with-windows-powershell-on-windows-server-2012.aspx
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Wednesday, December 05, 2012 8:36 PM
See how MS iSCSI initiator can be scripted:
http://technet.microsoft.com/en-us/library/hh826099.aspx
http://blogs.msdn.com/b/san/archive/2012/07/31/managing-iscsi-initiator-connections-with-windows-powershell-on-windows-server-2012.aspx
Unfortunately, these pages apply to Windows Server 2012, but I'm only running 2008 R2.Google is your friend :)
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