Hi Chris,
I am trying to create a 3.2TB partition on my Raid 5. Is there a
document that could help?
You can get generic information on partitions and how to create them at
http://www.faqs.org/docs/Linux-mini/Partition.html
I have a 3ware 9500 controller and 8 *500GB sata drives configured
into a single RAID 5 array.
I am running linux 2.6.16 with the 3ware drivers compiled into the
kernel.
I've tried a couple of different means to create the partition and
format the file system with xfs without success (or confidence that I
haven't done something wrong).
1. FDISK
I've tried fdisk on the array to create the partition; but it forces
me enter the number of cylinders before letting me create the
partition. I enter the largest number of cylinders since I'm not sure
how to calculate the correct cylinder number across an 8 disk RAID 5
array.
I then create the partition starting at 0 (or whatever the default
was) and ending at 3500GB.
Once the partition is created this way, I can mkfs.xfs; but I'm a
little hesitant to use this since I input and arbitrary cylinder number.
Thoughts on what to use for the correct cylinder count with fdisk?
It is not actually arbitrary. There are various options to create a
partition - can specify the size, sectors or cylinders. fdisk -l
/dev/<device> can hopefully give you details about the size of the disk,
cylinders etc. Now, it is upto to you as to how many partiotions you
want to create and use.
2. PARTED
I've tried to use parted without any success. Here is what I've tried
and the errors I get.
> parted
parted> mklabel gpt
parted> mkpart primary 0 3500GB
parted> quit
ok - the partition now exists. If I use ext2 everything works ok.
however, when I run
> mkfs.xfs /dev/sda1
the file system is formated but is truncated to to 2TB.
XFS can limit the FS size this way when AG count is just 2. xfs_info
<mnt_point> will list the details about the number of AG count. XFS can
support about 1 TB in one AG. By default, it calculates the agcount
automatically unless you force them. Your command line option does not
suggest this.
The 2 TB limit might be coming, perhaps, because parted uses 4 byte
addresses data structures. This way, it can support maximum of 2^32
sectors of 512 size ~ 41 bits ~ 2TB. It is my guess, though.
-shailendra
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