On network servers, it is an important requirement to ensure that the network interface is available at all times. On Red Hat Enterprise Linux 7, you can create aggregated network interfaces. Use network teaming or network bonding to accomplish this goal. In earlier versions of RHEL, network bonding was the default method for creating aggregated […]
Archives for September 2018
lvcreate/lvremove Failed with Error “Can’t remove merging snapshot logical volume”
The Problem Unable create or remove snapshot volume as error below: # lvcreate -s -L 3G -n snapopt /dev/vgOS/opt Logical volume “snapopt” already exists in volume group “vgOS” Whereas the logical volume is not present in any Volume Group. # lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert cplex vgOPT […]
How to Configure iSCSI targets on Solaris 10
iSCSI target feature has been available since s10u7. Here is some information for setting up a basic iSCSI target configuration. High level steps to follow are as shown below : create a base directory configure the backing store Creating a target Add ACL to target 1. create a base directory The base directory is used […]
How to obtain virtual/physical CPU information in Oracle VM (XEN)
This post explains how to obtain virtual or physical CPU usage of an Oracle VM Server, including actual CPU usage and running time of guest domains. Guest-specific (Dom-U) CPU usage can be obtained by running commands on the guest itself, for example; top, ps, and sar. If, however, you wish to obtain specific CPU usage, […]
iSCSI connection command examples (Cheat Sheet)
Internet Small Computer System Interface (iSCSI) is an Internet Protocol (IP)–based storage standard that connects iSCSI initiators to iSCSI targets over IP networks. To put it simply, the SCSI packets are encapsulated in IP packets and sent over a standard IP network, where the initiators and targets reassemble the packets and interpret the commands carried […]
“iscsiadm” Discovery TimeOut With Two Or More Network Interfaces in CentOS/RHEL
The Problem iscsiadm discovery times out when both the interfaces are up, but it works fine with single interface up. # iscsiadm -m discovery -t st -p x.x.x.x iscsiadm: connect to x.x.x.x timed out iscsiadm: connect to x.x.x.x timed out The Solution This issue could occur when two or more Ethernet interfaces are connected to […]
Unable To Extend LVM File System with Associated Snapshot in CentOS/RHEL
The Problem User is unable to Extend LVM file system which has snapshot, Error “Snapshot origin volumes can be resized only while inactive: try lvchange -an“. The user has created a snapshot on non-root LVM volume as shown below. # lvcreate –size 100M –snapshot –name testsnap /dev/testVG/testLV Logical volume “testsnap” created # lvs -a -o+devices […]
Solaris Zone Install Fails With Cpio Error
The Problem Error when trying to install full root zone ERROR: cannot install zone: cannot access [/usr/bin/cpio] (exec failure) NOTE: Sparse root install was successful. The Solution 1. Check the permissions of the cpio executable on the problematic system first. # ls -al /usr/bin/cpio -rwxrwxrwx 1 root bin 85924 Sept 9 2018 /usr/bin/cpio Correct permissions […]
RPM : package installation Error : cpio: read failed
The Problem We can see the following error while unpacking a package using rpm command; — Preparing… ################################################## dbaastools ################################################## error: unpacking of archive failed on file /var/opt/xxxx/xxx/xxx/xxx/xxx.o.zip.xxxxx: cpio: read failed – Inappropriate ioctl for device How to correct this issue and to install the package successfully. The Solution RPM uses cpio as it’s archive […]
Understanding the Hadoop MapReduce framework
This post introduces the MapReduce framework that enables you to write applications that process vast amounts of data, in parallel, on large clusters of commodity hardware, in a reliable and fault-tolerant manner. In addition, this post describes the architectural components of MapReduce and lists the benefits of using MapReduce. MapReduce It is a software framework […]