====== Disk ======

==== Partition UUID and Label ====
  * Get UUID and Label<code>
# blkid
/dev/sda1: SEC_TYPE="msdos" UUID="62AC-64E2" TYPE="vfat"
/dev/sda2: UUID="ebc16f0e-586d-466e-aba5-321016b401e9" TYPE="ext4"
/dev/sda3: UUID="9bb04b5a-e6c8-48ae-b802-4084f3943945" TYPE="xfs"
/dev/sda4: UUID="439969cb-2311-40e9-b1bc-6ede1bd185ef" TYPE="swap"
/dev/sdc1: UUID="6450978C50976398" TYPE="ntfs"
/dev/sdc2: UUID="fc5d0b9e-6092-410d-b000-c567be2eb940" TYPE="ext4"
/dev/sdb1: UUID="665d6352-b050-4702-b4f0-c6242c785127" TYPE="xfs"
</code>
  * More about UUID, WWID<code>
# ll /dev/disk/by-id
# ll /dev/disk/by-uuid
# ll /dev/disk/by-path

# WWID
# scsi_id -g -u -s /block/sda #for udev-095(OL5)
# scsi_id -g -u -d /dev/sda # for udev-147(OL6)
</code>

  * Change Label<code>
//ext2, ext3, ext4
# e2label <device> <label name>
//ocfs2
# tunefs.ocfs2 -L <label name> <device>
</code>

==== I/O Performance Test ====
Throughput<code>
# dd if=/dev/zero of=/dev/sda2 bs=1G count=1 oflag=direct
# dd if=/dev/zero of=/dev/sda2 bs=1M count=1000 oflag=direct
# hdparm -t --direct /dev/sda
</code>

==== LSI MegaRaid ====
  * Default virtual drive property
    * Access RW, Read Normal, Disk Cache NoChange, I/O Cached, Disable BGI No, Default Write Write Through.
  * Maximum HDD perf
    * Raid 0, 1, 10, Read Ahead, Write Thru(for streaming sequential)/Write Back(for transactional/random) Direct IO, Disk Cache Enabled
    * Raid 5, 6, Read Ahead, Whrite Back, Direct IO, Disk Cache enabled, full initialization.
  * Maximum SSD perf
    * Raid 0, 1, 10, No Read Ahead, Write Thru, Direct IO, Disk Cache Enabled
    * Raid 5, 6, No Read Ahead, Write Back, Direct IO, Disk Cache Enabled, Full initialization