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RAID - Collection of Information that I'm trying to learn.

=_= RAID =_=

1. How to confirm if your linux server has Hardware RAID installed in it?

Execute the command provided below.

/sbin/lspci -vv | grep -i raid

If it results an empty screen, you can confirm that there is no RAID hardware controller installed in the server.

2. How to confirm if there is Software RAID installed in the server?

Execute the command provided below.

cat /proc/mdstat

If it returns the below message, you can confirm that there is no software RAID installed in the server.

Personalities :
unused devices: <none>

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Qmail cheat sheet

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/var/qmail/queue/mess/22/524514 (mail headers)


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Logical volume vmxxxx_img is used by another device - Error on LVM removal

Hi Folks,

I've faced error while trying to remove an LVM from the server.

The exact LVM error will be "Logical volume vmxxxx_img is used by another device" on executing the lvremove command.

Feel free to remove the following steps to remove the LVM from the server.

Note: Please remember to replace <id> with your VMID in the below section.

dmsetup ls dmsetup info -c xen-vm<id>_img dmsetup remove xen-vm<id>_img lvremove -f /dev/xen/vm<id>_img ----------------------------------------------------------

Open VZ cheat Sheet


vzctl set 101 --diskspace 1000000:1100000 --save  To set diskspace for container with ID 101

vzctl set 101 --diskinodes 90000:91000 --save     To set inodes for container with ID 101

vzctl set 101 --quotatime 600 --save              To set quotatime for container with ID 101 (The time limit by

                                                       which container is allowed to temporarily exceed  its quota soft limits)

vzctl exec 101 df                                  To execute command df at the server with the CTID 101

vzctl set 101 --quotaugidlimit 100 --save          Set number of user/group id's allowed for internal disk
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 vzctl set 0 --dcachesize 5G --save        Set dcachesize of the hardware node

sysctl fs.fsync-enable=0     or  echo 0 > /proc/sys/fs/fsync-enable        disable fsync calls inside containers .

Add the  …