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iSCSI Initiator - New Files Not Being Displayed

    Question

  • 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!

    Wednesday, December 05, 2012 3:11 AM

Answers

  • 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):

    http://www.starwindsoftware.com/forums/starwind-f5/trying-clear-this-use-iscsi-instead-smb-t1392.html

    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:

    www.ardistech.com

    Hope this helped :)


    StarWind iSCSI SAN & NAS

    Wednesday, December 05, 2012 11:33 AM

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