Fractured = broken, ruptured; Noesis = cognition, knowledge
Watch out EMC, CoRAID is getting ready to grow.
CoRAID just got an infusion of Capital and a crack management team. Whithin 5 years they will be a common data center name or owned by a company that is already a big data center name.
This is really written as a reminder to me since I seem to have to go in search of this information whenever I need to format large disks.
Using parted for GPT.
The parted tool is very utilitarian but it gets the job done.
GPT is necessary for disks with space probably greater than 4 Terrabytes. (I can’t remember if it is 2 or 4 or 4.5) but it would probably be a good practice to start using it on anything over 2. GPT replaces the old style partition tables. The old FAT and BIOS restrictions are some of the last vestiges of 16 bit computing cruft we carry along with us into the 64-bit world.
The version of parted I was using didn’t have support for XFS. This example is borrowed from the Coraid web site:
shell # parted /dev/etherd/e0.0
(parted) mklabel gpt
(parted) print Disk geometry for /dev/etherd/e0.0: 0kB - 3001GB Disk label type: gpt
(parted) mkpart primary 0 1000G
(parted) mkpart primary 1000G 2000G
(parted) mkpart primary 2000G 3001G
(parted) print
Disk geometry for /dev/etherd/e0.0: 0kB - 3001GB
Disk label type: gpt
Number Start End Size File system Name Flags
1 17kB 1000GB 1000GB
2 1000GB 2000GB 1000GB
3 2000GB 3001GB 1001GB
(parted) quit shell
# cd /dev/etherd/ shell
# ls e0.0* e0.0 e0.0p1 e0.0p2 e0.0p3 shell
# mkfs.ext3 /dev/etherd/e0.0p1 shell
# mkfs.xfs /dev/etherd/e0.0p2 shell
# mkfs.reiserfs /dev/etherd/e0.0p3
in this case the disk in question is an AOE disk, but if you had a large SCSI array you would just substitute that instead of /dev/etherd/e0.0.
Parted can make the filesystem (mkfs) for you, type “help” at the (parted) prompt. EXT3 was not implemented in the version I was using.
`tune2fs -l /dev/sda1 | grep UUID” is how I find the UUID of the drive. If there are other ways to find the UUID of a drive I would like to learn them.
once you know the UUID for a drive you can mount it using just the UUID using the -U flag in the mount command:
mount -v -U 2ab524bc-3640-4dfd-bf4c-0373172e0159 -t ext3 /mnt/ether/
in the command above
-v yeilds verbose information about the mount command
-U tells the mount command to use the UUID of the device and is followed by the one we want to use. (those UUIDs are long aren’t they?)
-t tells the type of filesystem we are mounting. In this case, ext3. This is not always necessary
finally /mnt/ether/ is the directory I have set up for testing this etherdisk drive.
You can add the entry to fstab to cause a mount. Just remember if you are using aoe to make sure the aoe module is loaded first! Other large disk types won’t have that problem. This is what the entry should look like:
GUID=a241eee7-13e7-425d-854e-fa5ec1ee4c62 /mnt/largefs auto defaults 0 0
Now we have great big open file systems to save all that crufty old data on.