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Contribs.org Forums => General Discussion => Topic started by: holck on May 30, 2012, 09:15:07 AM

Title: RAID: need to change your old habits
Post by: holck on May 30, 2012, 09:15:07 AM

I am an old (+50) Linux and SME user, and must admit that the new SME versions with RAID have made things a bit difficult for me recently.

I bought a new server I wanted to use as a SME server. Without thinking too much about it, I placed two hard-disks (1 TB and 250 GB) in the cabinet, and installed SME8. My plan was to use one of the disks as a system disk and the other one for user data. But during install, the two disks were set up as a RAID1 array, meaning that effectively I now had only 250 GB available.

That was a bit unsatisfactory, so I installed another 1 TB disk, wanting to expand the available disk space to 1 TB. But even looking through the RAID page in the SME wiki, I was not able to change the RAID setup to use the two large disks with 1 TB available. So, stupid as I am, I tried to do a fresh SME install with all 3 disks installed.

Now the installation set up the disks as a RAID 1 array (the two large disks) with one spare disk (the smallest), but still only 250 GB available. Again I tried to kick the smallest disk out of the array, and grow it to use the total 1 TB, but with no success, probably just due to my own limited knowledge.

So, lesson learned: In the old days, you could just place disks in the server and later decide how you would like to use them. With the new SME versions with RAID, consider very carefully which disks you enter in your cabinet!

Jesper, Denmark

Title: Re: RAID: need to change your old habits
Post by: jumba on May 30, 2012, 09:55:09 AM

You should have searched a little more...


With a working 250 GB disk in the system, and adding an empty 1 TB disk, the raid would be 250 GB yes.
However, now swapping the 250 GB disk to another 1 TB disk, you can easily expand the raid to 1 TB following this page:

http://wiki.contribs.org/Raid


More exactly this part of the page:

Code: [Select]



mdadm --grow /dev/md2 --size=max

pvresize /dev/md2
lvresize -l +100%FREE main/root




I have done that several times when I need to add larger drives to a server. Works like a charm every time!  8) 8) 8)

Title: Re: RAID: need to change your old habits
Post by: janet on May 30, 2012, 02:26:05 PM

holck

For your original idea to work, you install ONLY the 250Gb drive first, then install the sme OS onto it.
Then power down and connect the second 1Tb disk, then use this howto to add it as another mounted drive
http://wiki.contribs.org/AddExtraHardDisk
(change hdxx to sdxx)

or
http://wiki.contribs.org/AddExtraHardDisk_-_SCSI

Title: Re: RAID: need to change your old habits
Post by: CharlieBrady on May 31, 2012, 02:57:38 PM

Quote from: holck on May 30, 2012, 09:15:07 AM

So, lesson learned: In the old days, you could just place disks in the server and later decide how you would like to use them.

This is simply not true. SME server has used two disks as a RAID1 pair for a very long term - since it was called e-smith server and gateway.

Jesper, I think it must be a long time since you have read the documentation, so I recommend you read it through a couple of times.