changing faulty hard drive

[dime111]

Hello
our problem is as follow
our main sata hard drive on server has started to fail so we need to change it with new hard drive before any real damage
i dont have such a experience on how we can do this
the OS ( centos) and all installed services (apache + mysql + php ) and all our virtual host and domains ( using whm /cpanel ) are on this faulty hard drive
also i dont have physical access to server and use SSH and whm to manage server
so how should this faulty hard drive be changed and all data be transfered to the new hard drive correctly so the system boot from new hard drive with all content in place ?
i have not done such a thing and im really confused
regards

[Rubberman]

You need somewhere to make a backup bit-image of the disc and/or file systems it contains. The easiest would be for a replacement drive with the same size and configuration as the system drive to be made available, and connected to the system. Then you would use the 'dd' command to copy the contents of the system drive over to the replacement drive, then have the system drive replaced with the replacement drive, and the system rebooted. Doing this all via ssh is not a really great idea, but possible. However, when/if you have problems then you are SOL until you (or someone under your instructions) can access the system physically...

So, get someone to attach a replacement drive to the system (with the current system drive still bootable), and get back to us for more detailed instructions. Just FYI, if the system drive is /dev/sda (likely), and the replacement drive is attached, then it should be /dev/sdb, or whatever. Assuming so, then you would do this (as root via ssh):

dd if=/dev/sda of=/dev/sdb

When that is done, you would have them replace the system drive with the new one that you copied to, and reboot the system. At that point, either it works, or it doesn't and you need to figure out why...

[Rubberman]

One other note (IMPORTANT) is that if there are other drives attached to the system other than the boot drive, then when the replacement drive is attached before you copy to it, it will NOT be /dev/sdb, but something else. I have a bunch of drives (15) on my system, so if I were to do this, the replacement drive would likely be /dev/sdp, but given how Linux figures out which device id to use, it could be almost anything... That's why I said to ask for further instructions when the new drive is attached.

[nujinini]

...I have a bunch of drives (15) on my system,

Please forgive my butting in but this is the first time I heard of a system with 15 drives. This just blows my mind. Wow!

[Rubberman]

8 in 2 arrays, 4 (internal) in an LVM, 1 system drive, 2 external esata drives (backup and other stuff). This isn't counting the 3TB (8 drives) in NAS enclosures. So, altogether, I have 23 hard drives online, comprising (excluding RAID redundancies) about 18TB of data. Inventory:

1 x 320GB system drive (I actually have 3 - each with a different OS, swappable)
4 x 500GB drives in an LVM (internal for /home)
4 x 2TB drives in JBOD array, mostly containing classic videos such as rips of my Doctor Who videos, old silent movies, etc.
4 x 1.5TB drives in RAID-5 backup array, containing bit-images of critical system data - frequently updated.
1 x 1.5TB drive for external backup (client data)
1 x 1.5TB drive for video files
4 x 500GB drives in RAID-5 NAS for Linux distributions, e-publications (books, magazines), and such
4 x 250GB drives in RAID-5 NAS for backups of audio CD's and mp3 rips of those albums. FWIW, I have over 1000 albums of music...

What's amazing, is how fast this stuff grows! It just reiterates my old saying - data expands to fill existing disc space + 10%...

[Irithori]

OT: I got more, I got more
Multiple DB Server, each one with 3 jbods (24 Drives each) + 16 Drives in the machine. That's 88

[Rubberman]

Ok. Let's run a "Who has the biggest personal drive farm" contest!

[Rubberman]

BTW, Irithori, I can only fit 6 internal drives in my workstation + 2 DVD drives (8 totoal). I've run mini-comps that could fit more internal drives, but not for awhile... I think for a standard pedestal type of under-desk workstation, 8 3.5" drives is about the max. I have also 4 small array enclosures (4x3.5" drives each), and another 2 drive carrier/enclosure. Altogether == 23 drives + 2 DVD recorders.

[Irithori]

Ok, in a private environment you win
I got only a 4Tb raid5 plus Backup.

[Rubberman]

Are we going for bragging rights now! Love ya Irithori!

Speaking of bragging rights, I got to spend a couple hours yesterday in a workshop with David "The Dawg" Grisman, playing mandolin and getting tips from The Dawg and his "assistant", Don Sternberg, two of the half-dozen best mandolin players in the world today. He even played my 107 year old Gibson mandolin, commenting "Wow, that's a nice instrument!". At least I learned some tips on playing weird keys like diminished and augmented sharp/flat keys as alternatives to standard variations. Brain is still throbbing!