January 2015


January 2015

Failed to activate new LV

If you like this article, please +1 or Recommend via FB with the provided buttons above: Article ID: 135 by: Reese K. Posted: 15 Oct, 2013 Last updated: 15 Oct, 2013 Views: 1486

Failed to activate new LV EDS etlprod2 ~ # lvcreate -l 14645 -n lv_dwstore vg_etlprod2 Not activating vg_etlprod2/lv_dwstore since it does not […]

Netmasks Table

Netmask Table

Decimal Binary CIDR Hex ——————————————————————- 11111111.11111111.11111111.11111111 /32 ffffffff 11111111.11111111.11111111.11111110 /31 fffffffe 11111111.11111111.11111111.11111100 /30 fffffffc 11111111.11111111.11111111.11111000 /29 fffffff8 11111111.11111111.11111111.11110000 /28 fffffff0 11111111.11111111.11111111.11100000 /27 ffffffe0 11111111.11111111.11111111.11000000 /26 ffffffc0 11111111.11111111.11111111.10000000 /25 ffffff80 11111111.11111111.11111111.00000000 /24 ffffff00 11111111.11111111.11111110.00000000 /23 fffffe00 11111111.11111111.11111100.00000000 /22 fffffc00 11111111.11111111.11111000.00000000 /21 fffff800 […]

turning off auto indent and comments in vi

It’s not always convenient to have auto comments or auto indent when pasting text enabled within a vi session. To turn them off, at least within the current vi session:

:set comments=

:set paste

Extract contents of initrd

How to extract and view contents of initrd

Depending on your version of linux, the /boot/initrd may be one of two formats:

cpio archive ext2 filesystem data The easiest way to determine what you’re working with is by using the file command. Here are examples showing the output for each file type listed in the […]

ip_conntrack: table full, dropping packet

ip_conntrack: table full, dropping packet At one point, there was high call volume into our support center of customers complaining about severe lag. One common denominator was that the customer base who called in happened to all reside on the same server, so investigation into the matter focused on that one particular system.

The server’s […]

The file /boot/grub/stage1 not read correctly

The file /boot/grub/stage1 not read correctly After pxe booting a server and installing linux from a cpio archive, grub failed to load using the grub-install command. The error presented was as follows:

root@pxe:~# mkdir /target root@pxe:~# mount /dev/sda1 /target root@pxe:~# chroot /target root@pxe:~# grub-install /dev/sda The file /boot/grub/stage1 not read correctly. Since command line didn’t […]

How to add a new LUN using EMC powerpath

How to add a new LUN using EMC Navisphere and powerpath Overview:

create a new LUN on an EMC Clariion CX3-40 via Navisphere assign LUN to proper Storage Group use powermt to bring LUN in and configure it rescan scsi bus on Linux server for new LUN bring new LUN under LVM control and create […]

Resizing an Online Multipath Device

Resizing an Online Multipath Device

If you need to resize an online multipath device, use the following procedure:

1. Resize your physical device

2. Use the following command to find the paths to the LUN:

# multipath -l 3. Resize your paths. FOr SCSI devices, writing a 1 to the rescan file for the device […]

sed one liners

sed one liners Insert character at beginning of line

Example: comment out all nfs entries in /etc/fstab

sed -i ‘/nfs/s/^/#/’ /etc/fstab

Uncomment out all nfs entries in /etc/fstab

sed -i ‘/nfs/s/^#//g’ /etc/fstab

Make a copy of a file, then substitue a string in the original

perl -i.orig2 -p -e ‘s/’ /etc/fstab

Print contents of a […]

EXT3-fs warning Directory index full!

At times, I come across the following message in syslog: kernel: EXT3-fs warning (device dm-3): ext3_dx_add_entry: Directory index full!

On systems in which this is being constantly logged to syslog, this can become rather annoying, but it is not a bug. It’s informing the user that somewhere within the system, a directory has more than […]