FC6 and disk larger than 2 terabytes

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FC6 and disk larger than 2 terabytes

Post by Basher52 » Sat Mar 31, 2007 8:36 am

Is this possible?
if it is how do I fix this?

I have bought a RAID card and I'm supposed to do a 2,5 Tb disk, buy I'm having big problems doing that, so for know I just partitioned them in the RAID manager program.
but now I just realized, DOH!, that I cant resize it if isn't one big array.
so I have to go back to one array but then I get into trouble.


anyone?

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Post by Void Main » Sat Mar 31, 2007 8:51 am

I don't understand what your issue is. Can you provide more details and explain what you mean by "get into trouble?"

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Post by Basher52 » Sat Mar 31, 2007 8:54 am

sorry thought that was clear :P

fdisk won't see the 2,5Tb disk just 2Tb, the same with parted.
and if I partition all the space I get a 2Tb disk.
I've been googling and I've found ppl saying that there is a limit of 2Tb
or is it?

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Post by Basher52 » Sat Mar 31, 2007 3:38 pm

I'm kinda seeing things more clearly now lol
I've been partying and now when I read it it sure stands out as an idiot post :( sorry mate and I understand if you won't be bothered with the post.

My question is how I, if it even is possible, create one big partition that's bigger than 2 TBytes and as I've read that 2TByes seems like it's a limit of some sort.
I've read mostly that a database bigger than 2TBytes is a problem, but I have found that even "normal" disks bigger than 2TBytes has some problems and that you have to fiddle with something to get this to work...
and THIS is my quesition, how do I do this?

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Post by Void Main » Sat Mar 31, 2007 3:41 pm

This looks like a workaround:

http://support.ironsystems.com/index.ph ... _id=2&id=5

If it were me I would probably create smaller partitions and then use LVM to create one big logical volume. LVM could have similar size limitations for all I know. I have never had to create a file system that large. :)

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Post by Basher52 » Sat Mar 31, 2007 7:33 pm

I've tried to use LVM some years ago, but when an error occurs I have never been able to fix it, due to my ignorance of how to fix it :(
everyone tells me that LVM is the thing to use, but if I can't handle it... :(
I'll see if i can figure one out :)

thanks, and from what I can see from this is that it is no solution to it

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Post by Void Main » Sat Mar 31, 2007 7:38 pm

What is no solution? LVM is pretty easy to set up and in Fedora it is actually set up by "default" at install time unless you tell it otherwise and partition your system manually. I actually did a little HOWTO for doing a couple of things manually with it a while back:

http://voidmain.is-a-geek.net/redhat/fe ... olume.html

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Post by Basher52 » Sat Mar 31, 2007 8:07 pm

well, I know it's default in Fedora, but i changed that to "ordinary" installing.
why you ask, well because when i got an error on that LVM I couldnt recover ANYTHING at all :( allthough I know pals that have, but my knowledge of it is not good enough to fix/handle an error in it within weeks :( and this timeperiod aint good enough :(

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Post by Void Main » Sat Mar 31, 2007 8:15 pm

Hmmm, and that other link with the workaround didn't work? You can also use software RAID and stripe the drives.

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Post by Basher52 » Mon Apr 02, 2007 1:35 am

the software raid seems fine, but i already bought a RAID card for almost $800 and I dont want to throw that money away.
To use smaller partitions and use software RAID or striping wouldn't fix my problem to add more disks to the RAID setup.
The disks are 500Gb and I have to have ONE raid setup or I cant add more disks to it in case it needs to get bigger.

I havent tried the workaround, I already filled the partitions with data.

what really is the workaround anyway? I tried to use parted but it didn't work.
Is it the label cos I didnt set one of those.

If I can put all the data somewhere I'll try this again sometime, but only if I know what the workaround is and that it'll work, cos even with Gbit NIC it sure takes a while to reup all the data again, think it took me almost a whole 24 hours last time.


UPDATE: I cant see any Geometry settings
this is what i get (on a testdisk made on the RAID card)

Code: Select all

(parted) p                                                                
Model: HPT DISK_2_0 (scsi)
Disk /dev/sdb: 600GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start  End  Size  File system  Name  Flags

(parted)

this is from fdisk:
(how can I already have a partition, I didnt make one, and in parted there is none)

Code: Select all

Command (m for help): p

Disk /dev/sdb: 599.7 GB, 599751917568 bytes
255 heads, 63 sectors/track, 72915 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       72916   585695231+  ee  EFI GPT

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Post by Void Main » Mon Apr 02, 2007 8:02 am

If you already have data on these disks that you don't want to lose and don't have a backup then I don't feel comfortable suggesting anything at all to you. Regarding the workaround all the instructions are in the message. I have not tried them so I can't say they will work. Again, if it were me I would use LVM. I am curious why you have to have a single file system that large? Maybe we could attack it from a different angle.

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Post by Basher52 » Mon Apr 02, 2007 10:25 am

well, I don't have to have one giant disk, but I have to have one big disk from the RAID card, after that I can, and I was trying to, partition the disk, but not fdisk nor parted could get the last cylinders of that big device
so I hade to partition it in in the RAID setup.

The problem is that if I don't have only one big disk created in the RAID I can't add more disks to it, at least as I've understood it, but I think I'm gonna mail support and ask just to be sure.

In the picture below I partitoned the disks in 3 parts
One is 1Tbytes and the other 2 equally 768Gb.

When I'm suppoed to add more disks I have to "mark" on the the RAID array and then add the disk, but since the arrays are NOT equal to the HDD size of 500Gb I can't add the disk, but as I said, I'm gonna email support and ask just in case. But my tests of the other array of disks point to the fact that I am correct in my assumption

Image

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Post by Void Main » Mon Apr 02, 2007 10:53 am

Can I ask you what the make/model is of your RAID controller? I see you are using RAID5 and you have 6 500GB drives attached. If I understand your issue you want to be able to add more disks at some point in the future and expand the size of the logical volume on your controller at that time. You claim you can do this if you create one large logical volume but not two smaller logical volumes. Do I have this correct? I would like to do some research on the issue if I can get your make/model.

Will it only allow you to create a single RAID set? That would be odd. For example with your 6 disks you should be able to create 2 stripe sets of 3 disks each and give you two logical disks of 1.5TB each (you don't have fault tolerance of course but this is just an example). Or with 2 more disks you could have 2 RAID5 logical disks at 1.5TB each. With 4 more disks you could have 2 2TB logical volumes. It would seem odd if you can't do that.

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Post by Basher52 » Mon Apr 02, 2007 11:31 am

The controller is a HighPoint RocketRaid 2340. http://www.highpoint-tech.com/USA/rr2340.htm

And yes you understood me correct :)
I have more than one RAID set, just created another 800Gb RAID 5 of 5 200Gb disks.

What I was hoping to accomplish is that if I add more disks all the partitions of that array will get bigger in size.

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Post by Void Main » Mon Apr 02, 2007 11:56 am

It looks like you would have been better off buying a lot more smaller disks so you could have created more smaller RAID sets. It will be interesting to hear if the manufacturer has any suggestions for you.
Last edited by Void Main on Mon Apr 02, 2007 7:21 pm, edited 1 time in total.

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