varsha 
vinay Vmware to Xen Conversion
cloudibee Here are the steps for converting Vmware windows/linux guest to Xen format. You need qemu-img tool for the conversion. If you are converting a Vmware Windows virtual machine guest, you…
HPUX : Kernel Tunable parameters
/usr/sbin/kctune is the administrative command for HP-UX kernel tunable parameters. It gives information about tunable parameters and their values, and makes changes to tunable values. To list all tunable paramters…
Some Netapp terms..
Snapshot – is a technology that helps to create point-in-time copies of file systems, which you can use to protect data as a backup from a single file to a…
Xen management : virsh commands
You can use virsh to manage xen virtual servers. Here are some basic commands using virsh. To list all the xen virtual machines configured on the dom0 server : #…
Linux : Tunable TCP /proc parameters
Tunable TCP settings can be found on /proc/sys/net/ipv4 . Here are the details of few of them.tcp_keepalive_probes : Number of KEEPALIVE probes tcp sends out, until the server decides that…
prelink: Improve your system performance.
prelink is a program which modifies ELF shared libraries and ELF dynamically linked binaries, so that the time which dynamic linker needs for their relocation at startup significantly decreases and…
sginfo : Disk information
sginfo command in Linux can be used to get information about the SCSI disks on the system. Display disk vendor, product code and firmware version : # sginfo /dev/sddDevice Type…
Performance : Throughput analysis using iozone.
The throughput of local filesystem or an nfs mount can be captured using iozone. The below command starts throughput calculation on /d1 filesystem , with 2 IO threads working on…
Linux : Virtual filesystem – Loopback device
Sometimes you may need additional local partition or local mountable drives, but you dont have free blocks in the parition table. In that case virtual filesystem helps. You can create…
NFS client : rsize wsize
The nfs client mount command options “rsize” and “wsize” specify the size of the chunks of data that the client and server pass back and forth to each other. If…
Linux : Forcing fsck on nxt boot
If you want to force fsck on the next boot, just create a file called /forcefsck . If this file is present, then during next boot – the fsck is…
Encrypting a tar file using openssl
In some cases, you may have to send your datacenter’s passwd information to some of your collegues. Instead of sending them in plain text, you can use tar & openssl…
Loadbalancer
A good presentation from F5 explaining all features of Loadbalancer : http://www.f5.com/flash/product-demo/
Download using wget
You can use “wget” on Linux machine CLI to download files from http or ftp sites. Proxy configuration can be done for wget by exporting environment variables Initialize proxy :…
Netapp : nfsstat command
This command displays the NFS and RPC statistics of filer. The command can be used to find the performance bottlenecks in NFS environment. This shows the metrics for each nfs…