AnsweredAssumed Answered

Support for >2TB disks on Centos 5.x

Question asked by tc_dev on Mar 24, 2012
Latest reply on Mar 24, 2012 by srivas
I would like to clarify the right way to deploy MapR on the largest disks.

Having installed a new 3TB Seagate Barracuda disk (STBD3000100) I found that both "fdisk -l" and MapR Control System can only recognize the first 2.2TB, consistent with DOS partition table limitation:

    [root@hostname ~]# fdisk -l 
    ........
    Disk /dev/sdb: 2199.0 GB, 2199023255040 bytes
    255 heads, 63 sectors/track, 267349 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    
    Disk /dev/sdb doesn't contain a valid partition table
    [root@hostname ~]#

Seagate documentation directs me to their "beyond 2TB" support site that says that larger disks are automatically recognized by Linux kernels "v2.6.35 or newer" which excludes CentOS 5.x  
http://www.seagate.com/www/en-us/support/beyond-2tb/  
http://knowledge.seagate.com/articles/en_US/FAQ/218575en  

I could see a possible solution being to format the disk as GPT using Parted and if it succeeds at creating a 3TB GPT partition (/dev/sdb1) then install MapR FS there. I have done this kind of formatting on another box (non-MapR) and here is how fdisk sees that format:

    [root@hostname ~]# fdisk -l
    ........
    WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util fdisk doesn't support GPT. Use GNU Parted.
    
    Note: sector size is 4096 (not 512)
    
    WARNING: The size of this disk is 3.0 TB (3000592977920 bytes).
    DOS partition table format can not be used on drives for volumes
    larger than 2.2 TB (2199023255040 bytes). Use parted(1) and GUID
    partition table format (GPT).
    
    
    Disk /dev/sdd: 3000.5 GB, 3000592977920 bytes
    255 heads, 63 sectors/track, 45600 cylinders
    Units = cylinders of 16065 * 4096 = 65802240 bytes
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdd1               1       45601  2930266576   ee  EFI GPT
    [root@hostname ~]#

My question is whether installing MapR-FS on large-sized GPT partitions is supported / tested and if not what is the alternative solution. The reason I am even asking is because MapR Control System only sees the disk (/dev/sdb) as 2TB...

Outcomes