Comments

Post a Comment

Popular posts from this blog

BAD_ADDRESS FLOOD IN WINDOWS DHCP SERVER

Image
How a single misbehaving client can take down your network Well, not really your entire network but definitely DHCP. I came across a linux client that had issues with assigning an IP address using dhclient. The dhclient process would throw a null pointer exception during the phase in which it attempts to validate the assigned IP address. From here, dhclient sends a DHCPDECLINE message to the server. The DHCPDECLINE message tells the server that something is either wrong with the DHCP parameters or that the client discovered that the IP was in use (through gratuitous ARP or in this case, a failed attempt at sending a gratuitous ARP). cat /var/log/messages  : RFC 1541 states: “If the server receives a DHCPDECLINE message, the client has discovered through some other means that the suggested network address is already in use. The server MUST mark the network address as “not allocated” and SHOULD notify the local system administrator of a possible configuration pr...
Read more

ESXI REMOVE ALL SNAPSHOTS HANGS AT 99%

Image
Check and make sure that the process is actually stuck and not just taking a very long time. To do this, follow these steps: 1. Make sure SSH service is running on the ESXi host Navigate to configuration -> security profile -> services -> Click on Properties Choose the ‘SSH’ service, ‘Options’, and click ‘Start’ Once SSH is enabled, connect to the ESXi host using your favorite ssh client. 2. Run ->   vim - cmd  vmsvc / getallvms Find the vmid of the virtual machine, in this case its 20. 3. Now run ->   vim - cmd  vmsvc / get . tasklist   20 <-   this is the # of the vm from above 4. Find the removeallsnapshots task # then run: vim - cmd  vimsvc / task _ info   185720854  <- this # will be different for you If you see:   “The object has already been deleted or has not been completely created”  or similar, your snapshot removal is probably frozen, but in order to be sure, let’s loo...
Read more

Windows Server: How to Repair the Boot Files in Windows Server 2008 or 2008 R2 if the Server Won’t Boot

There are a number of possible causes for the failure of a server to boot into Windows. This article deals with a problem in the boot files and demonstrates how to repair them. Solution IMPORTANT: Drive Letters Change in WinRE When booting to the Windows Recovery Environment (WinRE), the drive letters are assigned on a first-come, first-serve basis. For example, the C: drive in Windows will often have a different letter in WinRE. The DiskPart utility can be used to keep track of the drives and what is stored on them. Restoring Boot Files   Note:  If there is no System Reserved partition. It is okay to select the drive containing the Windows folder . First Partition: 100 MB System Reserved (No drive letter) Second Partition: 60 GB (C:) OS Third Partition:1.5 TB (D:) Data DVD Drive: E:   Note:  The DVD drive’s letter changes from E: to F: in WinRE. Boot to the Windows Server DVD. Open the command prompt. Server 2008 R2 If no driver is needed, p...
Read more