Change disk sector size from 520 bytes to 512 bytes

If you happen to have an old SAN which contains perfectly usable disks, you might experience that hooking these disks onto youe SAS HBA/Raid-controller won’t work out of the box. I recently pulled 11 disks from an old EMC AX-4 for reuse in a PowerEdge 720XD (10 disks for RAID-10 plus 1 hotspare and 1 SSD for CacheCade), and noticed that the disks had an unsupported formatting. I forgot to screenshot the info from my disks, so I snipped the info from

From dmesg

[ 86.717949] Vendor: IBM Model: IC35L146 CLAR146 Rev: R58A 
[ 86.717970] Type: Direct-Access ANSI SCSI revision: 03 
[ 86.720959] sdb : unsupported sector size 520. 
[ 86.720966] SCSI device sdb: 0 512-byte hdwr sectors (0 MB) 
[ 86.722822] sdb: Write Protect is off 
[ 86.722828] sdb: Mode Sense: e3 00 00 08 
[ 86.725797] SCSI device sdb: drive cache: write through 
[ 86.725908] sd 0:0:1:0: Attached scsi disk sdb 
[ 86.726103] sd 0:0:1:0: Attached scsi generic sg1 type 0

As can be seen – these disks had an unsupported sector size (520 vs the regular 512). In order to get the disks working I installed the sg3_utils on my CentOS machine.

Perform a scan and see the disks available for a sector size change

# sg_scan -i
/dev/sdb: scsi channel=0 id=2 lun=0
Vendor: IBM Model: IC35L146 CLAR146 [rmb=0 cmdq=1 pqual=0 pdev=0x0]

As said – my output wasn’t exactly like this, but you get the idea… Then perform the sector size change

# sg_format –format –size=512 /dev/sdb
Vendor: IBM Model: IC35L146 CLAR146 peripheral_type: disk [0x0]
Mode Sense (block descriptor) data, prior to changes:
Number of blocks=573653847 [0x22314357]
Block size=520 [0x208]
A FORMAT will commence in 10 seconds
ALL data on /dev/sg8 will be DESTROYED
Press control-C to abort

I had Seagate 600GB 15k disks, and I believe the formatting was close to 60 minutes per disk. I had 11 of these, and to speed things up I just did’em all in parallell 😉 The PERC complains about unsupported disks, but I imagine these disks will work just fine in our dev-environment.


Windows Storage Spaces 2012 – some references

Just a few links and references that I’ve found helpful…

Installing and updating Dell OpenManage on Redhat/Centos 6.4

For my own referance I copied some useful info from (i.e. this is not MY writings)

I have updated my Dell OpenManage installer script to address several compatibility issues with Dell PowerEdge G12+ systems. The following Dell OpenManage Server Administrator (OMSA) installation script is suitable for RedHat 6.4x and CentOS 6.4x systems

1. Login to your server via SSH.
2. Change directories to your source store:

# cd /usr/src

3. Create the install script:

# nano -w

4. Cut and paste the following text:

# Dell OpenManage Installer (DOMI)
# Revision: June 25th 2013
D=`date '+%d%m%y'`
echo "Dell OpenIPMI & OpenManage Automatic Installer"
echo "Revision: July 25nd 2013"
read -p "Press [Enter] key to begin the installation or [CTRL+C] to exit."
echo "Installing OpenIPMI..."
yum -y install OpenIPMI
echo "Installing Dell Yum Repository..."
wget -q -O - | bash
echo "Dell Repository Install Complete!"
echo "Installing Dell Server Administrator..."
yum -y install srvadmin-all
echo "Dell Server Administrator Install Complete!"
echo "Starting Dell IPMI Services..."
/opt/dell/srvadmin/sbin/ start
echo "Dell OpenIPMI & Dell OpenManage Install Complete!"
echo "To access Dell OpenManage go to: https://$HOST:1311 and login with username root and your password."

5. Save and exit nano (CTRL+X the Y to Save then exit)

6. Run the script:

# sh

7. Once the script has completed you will be able to login to Dell OpenManage at https://your-server:1311 with your root username and password.

NOTE: If you receive dependency errors I recommend force uninstalling the problematic packages (e.g. rpm -e –nodeps $packagename), completing the OpenManage install then re-install the package again.

Konvertere Dell Perc H200 og Dell SAS 6/i til IT-mode

Har du behov for en god kontroller til en rimelig penge for f eks ZFS så er Dell PERC H200 et greit alternativ. Kortet er basert på LSI 2008 chip’en, tilsvarende IBM M1015 og LSI 2211-8i. I utgangspunktet er kortet satt opp med BIOS og RAID-funksjonalitet når det leveres fra Dell, men ytelsen er mildt sagt elendig med RAID konfigurert. Testet med RAID-1 under VMware ESXI 5.1 U1 ga ca 50mb/s i skriv med 2 x 120gb Corsair GT.

For skikkelig ytelse (opp mot 1200mb/s, om enn mulig noe teoretisk) – bytt firmware (tilgjengelig fra Dell!) og gjør kortet om til et rent SAS HBA-adapter som funger som gull :o)

Tilsvarende prosedyre kan også brukes med Dell SAS 6/i kort –