How to add a new hdd to linux server.

Issue the command  fdisk -l,  you can see the new hard disk connected to the server.

For example:
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Disk /dev/sda: 1500.3 GB, 1500301910016 bytes
255 heads, 63 sectors/track, 182401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14      182401  1465031610   8e  Linux LVM

Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes
255 heads, 63 sectors/track, 182401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table
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Then you need to create a partition in the new server. Using the command 'n', you can create a new partition. Select the partition number and issue the command "w" to write write the partition.

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Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.


The number of cylinders for this disk is set to 182401.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)


Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
e
Partition number (1-4):
Value out of range.
Partition number (1-4): 1
First cylinder (1-182401, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-182401, default 182401):
Using default value 182401

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

----------------------------------

Then you have to create a file system in the new hard disk.
mkfs -t ext3 /dev/sdb1  or mkfs.ext3 /dev/sdb1

------------------------------------------
[root@localhost ~]# mkfs.ext3 /dev/sdb1
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
183091200 inodes, 366181585 blocks
18309079 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
11175 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000, 214990848

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:
done

This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
---------------------------------------------

Then you have to mount the hard disk to the directory /home1


mount /dev/sdb1 /home1

Exim : 451-The server has reached its limit for processing requests from your host.n451 Please try again later.

451-The server has reached its limit for processing requests from your host.n451 Please try again later.

its probably exim's ratelimiting, add your servers IP's to the whitelist in WHM > Exim Configuration

Also check the value of the 'Maximum Emails a Domain Can Send In 1 Hour' value in WHM > Tweak Settings

retry time not reached for any host after a long failure period

exim_tidydb -t 10m /var/spool/exim retry
exim_tidydb -t 10m /var/spool/exim wait-remote_smtp