iSCSI Setup

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iSCSI Setup Powered By Docstoc
               iSCSI Terms
An iSCSI initiator is something that requests
  disk blocks, aka a client
An iSCSI target is something that provides disk
  blocks, aka a server.
An iSCSI portal is the combination of the IP and
  Port of a target
   Initiator             Portal:


Windows/Linux/OSX box,
Mounting the target as              Linux box, providing a
A block device                      disk as an iSCSI target
In this case, the target is a linux box running
  the iSCSI daemon. The IP and the port the
  daemon are listening on are the portal. Any
  device that can act as an iSCSI initiator can
  connect to the portal and treat the device as
  a block device
The space served by the target is a raw disk
                  iSCSI Setup
On the server side, setup is still somewhat nasty. has a linux implementation
   of iSCSI
You need to recompile the kernel; kernel 2.6 or more
   recent is required
Yum update kernel kernel-devel to get the necessary
Export KERNELSRC=/usr/src/kernes/2.6.14…
Make, make install
Init scripts installed in /etc/rc.d, /etc/init.d
                  iSCSI Target
Target address format:
“iqn” is the type (iSCSI Qualified Name)
2004-04 is the date of the first full month the naming
   authority was registered
Edu.nps is the reversed domain name, the naming
   authority is a name assigned by you
Basically, you only have to worry about the last field
                Etc config
In /etc. ietd.conf controls name
Target iqn.2001-
Lun 0 Path=/dev/sdb
/etc/iscsi has some other config parameters
         Client Side (Initiator)
Now that the target (provider of disk space) is
  set up we can configure the client.
On Windows, get the MS iscsi initiator (google)
  and run the installer
Start iSCSI initiator and specify the IP and port
  to connect to

          QuickTime™ and a
   are neede d to see this picture.

Note that the name
matches the name we
provided in the ietd.conf
file--we connected
successfully                                 QuickTime™ and a
                                      are neede d to see this picture.
At this point we have block device access to the
  device. On another system I created a FAT
  filesystem, so we can also show this as a FAT
NOTE: If two machines have block access, they
  WILL eventually put the FAT filesystem into
  an inconsistent state. Ditto for ext, zfs, ntfs,
  and other single-host filesystems
              iSCSI on OSX
Supposedly iSCSI was going to be part of
  Leopard--it didn’t make it. Probably be added
  at some later date
There are free iSCSI initiators available,
Run installer; adds a .kext kernel extension,
  which requires a reboot

Note IP and 3260
                              QuickTime™ and a
                        are neede d to see this picture.

Connection established;
note match of
iscsi ID with that of the
target config file                       QuickTime™ an d a
                                  are need ed to see this p icture .
          Filesystem Creation
Once you have access to the iSCSI drive as a
 block device, you can create a filesystem on
 the device.

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Again, conventional filesystems are designed to
  have only one OS access them as a block
We can have multiple hosts contact the iSCSI
  block device. A conventional filesystem will
  eventually become inconsistent if you do
  writes from multiple hosts
          What did we get?
We accessed a block device on a linux server
  from OSX and Windows across an IP network
  using commodity ethernet (or wireless)
This isn’t quite a SAN, since we don’t have
  volume management, but it provides the
  substrata needed for that
         Volume Management
This is somewhat tricky and still a developing
  field. There are a number of commercial
  implementations and a few open source
This is the layer that handles concurrent access
  to block devices
What would a cluster architecture look like with
 a SAN?
              iSCSI devices
No endorsement implied by any mention of a
  vendor, prices variable….
Promise vtrack: ~$5K for enclosure, plus disk
16 SATA bays, 3U, RAID, TCP Offload Engine

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                                  iSCSI Devices
HP Storage Works AIO 1200, 600, 400
SATA or SAS drives possible
~ $8K for 3 TB

                  Qu i ckTi me ™ an d a
                     de co mp res so r                       Qu i ckTi me ™ an d a
         a re ne ed ed to se e thi s p i ctu re .               de co mp res so r
                                                    a re ne ed ed to se e thi s p i ctu re .
Sun is generally dismissive of iSCSI for their
  enterprise storage products
EMC has an installed base in FC, though they
  do offer iSCSI in parallel on some boxes
EMC is partnered with Dell: AX150 (12 SATA
  drives, 9 TB, RAID) $11K for 1.5TB (Massive
  discounts probably apply)
CX3 series: up to 144TB, enterprise stuff

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