DNS Resolution bug?
Posted: Tue Feb 16, 2010 1:32 pm
Infrastructure:
2x HP DL320s running latest iStorage, Windows 2003 x64 R2 standard. Two NICs; one on main network, one on separate specifically for iSCSI traffic. Bound into domain. Logged in with Domain administrator-level account. IP-authentication use for all connections.
History:
After setting up the two systems and doing a lot of testing (including recovery after storage server reboot) with the client being a non-production machine but bound into the Domain, we prepared to connect one of our production ESX servers. Connection went fine. However, after rebooting the iStorage server (testing failure/recovery) all iSCSI targets disappeared out of the iStorage server console. I checked the XML file, and it didn't contain any info on the targets any more.
After a lot of testing, analyzing and rebooting servers I discovered that if the computer name listed when using IP-Authentication came up with "could not resolve host" then on reboot the "locals.xml" file containing target information was over-written without target information. Once I added a DNS or hosts file entry for the client's IP address the issue quit happening. If I then added another non-resolvable client, the issue re-appeared. 100% reproducible on both servers. These clients were not in the DNS system because they are not bound into the domain (ESX boxes) and were on the secondary subnet. Easy enough fix, but potentially breaking; it would really suck to have a few dozen iSCSI targets in production then have the config files blown up because you forgot to add a server into the DNS system...
2x HP DL320s running latest iStorage, Windows 2003 x64 R2 standard. Two NICs; one on main network, one on separate specifically for iSCSI traffic. Bound into domain. Logged in with Domain administrator-level account. IP-authentication use for all connections.
History:
After setting up the two systems and doing a lot of testing (including recovery after storage server reboot) with the client being a non-production machine but bound into the Domain, we prepared to connect one of our production ESX servers. Connection went fine. However, after rebooting the iStorage server (testing failure/recovery) all iSCSI targets disappeared out of the iStorage server console. I checked the XML file, and it didn't contain any info on the targets any more.
After a lot of testing, analyzing and rebooting servers I discovered that if the computer name listed when using IP-Authentication came up with "could not resolve host" then on reboot the "locals.xml" file containing target information was over-written without target information. Once I added a DNS or hosts file entry for the client's IP address the issue quit happening. If I then added another non-resolvable client, the issue re-appeared. 100% reproducible on both servers. These clients were not in the DNS system because they are not bound into the domain (ESX boxes) and were on the secondary subnet. Easy enough fix, but potentially breaking; it would really suck to have a few dozen iSCSI targets in production then have the config files blown up because you forgot to add a server into the DNS system...