[CentOS] ssd quandry

Sun Oct 23 07:07:59 UTC 2011
John R Pierce <pierce at hogranch.com>

On a CentOS 6 64bit system, I added a couple prototype SAS SSDs on a HP 
P411 raid controller (I believe this is a rebranded LSI megaraid with HP 
firmware) and am trying to format them for best random IO performance 
with something like postgresql.

so, I used the raid command tool to build a raid0 with 2 SAS SSDs

# hpacucli ctrl slot=1 logicaldrive 3 show detail

Smart Array P410 in Slot 1

    array C

       Logical Drive: 3
          Size: 186.3 GB
          Fault Tolerance: RAID 0
          Heads: 255
          Sectors Per Track: 32
          Cylinders: 47869
          Strip Size: 256 KB
          Status: OK
          Array Accelerator: Enabled
          Unique Identifier: 600508B1001C2EDB6026F9ADF9F88A09
          Disk Name: /dev/sdc
          Mount Points: /ssd 186.3 GB
          Logical Drive Label: AF36B716PACCRCN810E1R9J646A

# hpacucli ctrl slot=1 show config

Smart Array P410 in Slot 1                (sn: PACCRCN810E1R9J)
....
    array C (Solid State SAS, Unused Space: 0 MB)


       logicaldrive 3 (186.3 GB, RAID 0, OK)

       physicaldrive 1I:1:23 (port 1I:box 1:bay 23, Solid State SAS, 100 
GB, OK)
       physicaldrive 1I:1:24 (port 1I:box 1:bay 24, Solid State SAS, 100 
GB, OK)

# hpacucli ctrl slot=1 show ssdinfo detail

Smart Array P410 in Slot 1
    Total Solid State Drives with Wearout Status: 0
    Total Smart Array Solid State Drives: 2
    Total Solid State SAS Drives: 2
    Total Solid State Drives: 2


    array C

       physicaldrive 1I:1:23
          Port: 1I
          Box: 1
          Bay: 23
          Status: OK
          Drive Type: Data Drive
          Interface Type: Solid State SAS
          Size: 100 GB
          Firmware Revision: 1234
          Serial Number: 999999999999999999
          Model: XYZZY M2011
          Current Temperature (C): 30
          Maximum Temperature (C): 37
          SSD Smart Trip Wearout: Not Supported
          PHY Count: 2
          PHY Transfer Rate: 6.0GBPS, Unknown

       physicaldrive 1I:1:24
          Port: 1I
          Box: 1
          Bay: 24
          Status: OK
          Drive Type: Data Drive
          Interface Type: Solid State SAS
          Size: 100 GB
          Firmware Revision: 1234
          Serial Number: 999999999999999999
          Model: XYZZY M2011
          Current Temperature (C): 29
          Maximum Temperature (C): 36
          SSD Smart Trip Wearout: Not Supported
          PHY Count: 2
          PHY Transfer Rate: 6.0GBPS, Unknown



# tail /var/log/messages
Oct 22 22:56:24 svfis-dl180b kernel: sd 0:0:0:3: Attached scsi generic 
sg3 type 0
Oct 22 22:56:24 svfis-dl180b kernel: sd 0:0:0:3: [sdc] 390611040 
512-byte logical blocks: (199 GB/186 GiB)
Oct 22 22:56:24 svfis-dl180b kernel: sd 0:0:0:3: [sdc] 8192-byte 
physical blocks
Oct 22 22:56:24 svfis-dl180b kernel: sd 0:0:0:3: [sdc] Write Protect is off
Oct 22 22:56:24 svfis-dl180b kernel: sd 0:0:0:3: [sdc] Write cache: 
disabled, read cache: enabled, doesn't support DPO or FUA
Oct 22 22:56:24 svfis-dl180b kernel: sdc: unknown partition table
Oct 22 22:56:24 svfis-dl180b kernel: sd 0:0:0:3: [sdc] Attached SCSI disk
Oct 22 22:56:36 svfis-dl180b cmaeventd[2540]: Logical drive 3 of Array 
Controller in slot 1, has changed from status Unconfigured to OK

# mkfs.ext4 /dev/sdc
mke2fs 1.41.12 (17-May-2010)
/dev/sdc is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=8192 (log=3)
Fragment size=8192 (log=3)
Stride=1 blocks, Stripe width=0 blocks
12210528 inodes, 24413190 blocks
1220659 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4311218176
373 block groups
65528 blocks per group, 65528 fragments per group
32736 inodes per group
Superblock backups stored on blocks:
         65528, 196584, 327640, 458696, 589752, 1638200, 1769256, 3210872,
         5307768, 8191000, 15923304, 22476104

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done


# mount -t ext4 /dev/sdc /ssd
mount: wrong fs type, bad option, bad superblock on /dev/sdc,
        missing codepage or helper program, or other error
        In some cases useful info is found in syslog - try
        dmesg | tail  or so

# tail /var/log/messages
...
Oct 22 23:54:36 svfis-dl180b kernel: EXT4-fs (sdc): bad block size 8192

ok, so lets try 4K blocks?

# mkfs.ext4 -b 4096 /dev/sdc
mke2fs 1.41.12 (17-May-2010)
/dev/sdc is entire device, not just one partition!
Proceed anyway? (y,n) y
mkfs.ext4: Invalid argument while setting blocksize; too small for device



hmmm.   can't do that either?

can I configure this 64bit system for large pages or something so it 
will support 8K blocks?




-- 
john r pierce                            N 37, W 122
santa cruz ca                         mid-left coast