Hi

I recently had to do some installations on a windows server running on a VM. This made me have a look at the VSS technology and at the end can to the conclusion that VSS has limited usefulness for most Oracle sites. Now someone might correct me and show what is missing in my understanding but without regular say hourly snapshots to another place its adds little value. Wouldn’t a daily rman backup and regular backups of archive logs provide a better alternative?

I understand some SANS can provide SAN mirroring with the use of VSS, but to do this the database still have to be quiesced. From what I looked at Data Guard is a much better solution for a recovery from many failure situations. Doing snapshots with VM technology leaves you with a potentially degraded database, some testing suggested in a slow system, that is one with a very low transaction rate it perhaps will be recoverable. Some testing I did left me with  a question mark over what might happen in the event of  a problem occurring.

I ran some tests and had it snapshotted whilst conducting a number of transactions using Jmeter to create some traffic on the database without using VSS to determine if a database was recoverable from a snapshot, in each case as the redo logs were ok the database recovered and started, I identified that this was only good luck as in different circumstances this could easily been in a situation whereby this database became unrecoverable, basically what had happened was all my redo logs were still at the same SCN number and as such the database simply recovered as when a shutdown abort occurs.

Oracle provides a fantastic tool in RMAN and Data Guard if you need fast recovery from some situations and using VM snapshots with VSS  or without may not be your best option, check out thoroughly any recovery scenarios you may need to handle and especially your lost time window when you cannot apply logs before choosing one over the other. I am sure in many cases Oracle will provide you with better alternatives than external tools such as VM snapshots.

What has been your experiences and what paths have you chosen and why? I am interested to hear

See ya round

I recently installed  Checkpoint VPN-1 SecureClient software onto a system running XP SP3 with ZoneAlram Extreme Security installed. After running into an issues where WinSCP would run at 100% CPU utilization I decided to investigate. My initial investigation led me to deciding to remove the VPN-1 SecureClient. This was to prove to be a nightmare exercise. I removed the client or so I thought after uninstalling it and rebooted.

I then started getting an issue with BSOD DRIVER_IRQ_NOT_LESS_OR_EQUAL and the vdatant.sys was apparently the culprit. I ended pointed to a couple of notes suggesting this was Zone Alarm. Easy enough I think just uninstall ZoneAlarm and reinstall it. No not quite, still getting these BSOD.

Of to do some more research and I come across a note to use Cpclean to get rid of VPN-1. No problems nice to have a clean up tool. Ran it said it was going to remove some registry keys, good I thought. Ran WnSCP and nope still not right 100CPU, it seems this was due to excessive packet inspection. Saga continues, ok remove ZoneAlarm again, ran CPClean still a problem. Yes I now had no network connection at all. The VPN-1 software had trashed my network stack.

Decided to install some diagnostics and they wanted to have some Windows Network tools SNMP installed. I tried to do that but I don’t have a copy of SP3 that it wanted.  Now I had a problem, I was not sure if I had just reinstalled a SP2 or SP1 version file and I was now getting random lockups. I grabbed some software on my MAC latest Drivers for this Network card and reinstalled the software and yeah I was back online but still unstable, I was getting random lockups.

Next step I did some research could I get my machine back to a state of having SP3 with all the latest updates. Oh yeah I found WindowsUpdateDownloader. Cool, wonderful tool I could now download all SP for my machine since SP3, I reinstalled SP3 and then downloaded all the windows updates and chronologically reinstalled them, about 60 or so. Well it looks like stability had returned. I then proceeded to run CPclean again and it said there were a few keys there for Checkpoint. Next I manually searched and removed from the registry any  remnants of the Checkpoint VPN-1 Software and SecureClient, a few different keyword searches uncovered the majority and  cleaned it out.

So no I felt my system was stable and Checkpoint VPN was gone, so test again and see if WinSCP either caused BSOD or caused high CPU. Yeah!! No issues present, file transferred normally and the system seemed OK. Next trick reinstall ZoneAlarm. Pretty straightforward its key with the license was still present so it automatically got going and after a couple of days it seems well again.

Clearly there should be a huge Warning from Checkpoint about installing its VPN software on the same OS that is running ZoneAlarm. Surely they test that sort of stuff.

Moral of the story you cant run VPN-1 on a system running ZoneAlarm if you have a need look into using VM’s to do the dirty work then you have the choice of having  a VPN-1 VM for that site.

All is good now so I am happy again but it lost me close to three days of full productivity cleaning up and reinstalling to rid the issues.

See ya round

Peter

Oh no non Oracle post

A few months ago I upgraded my home office to have a Netgear WNDR3700 wireless Router Dual N as they refer to it. Overall it has proven to be a great product albeit with a bug regarding image file on usb devices attached to it (not a big issue here). Early this month I bought an Acer Emachine Netbook  for the house and could only get it to work on the Guest network which I have configured with WEP (yes I know about the security unfortunately the DS only has WEP. So we need a WEP secure network available.  I had that network configured on the router to not be able to connect to local resources on my lAN only use Internet.

Unfortunately I have through some research come to the conclusion the Atheros chip set or its drivers are pretty substandard and am starting to get a distaste for their shortcomings. Generally the Linux drivers are difficult to get working and the Windows ones seem to come up short in their capabilities. This applies across Ethernet and Wireless drivers that I have used in recent months. It might make me shy away now from Asus of which I had generally preferred as my mother board manufacturer and from any devices that uses Atheros chip sets.

I wonder if this is not dissimilar to the problem that has been experienced with the IPad, Apple says name the Networks the same and use the same encryption, I wonder if that will work, A test is coming up unless a reader has some answers

See ya round

Peter