hmmmm .. did you google groups ?

http://groups.google.co.uk/groups?q=...=1&sa=N&tab=wg

The answer looks like "no" linux does not support SSA.

Rgds
Mark Taylor

However ref: http://www.vergenet.net/linux/redund...y-HOWTO-7.html

Linux SSA Device Driver

There is no Linux SSA device driver today, however IBM Systems Storage
Division (SSD) will support us to get one written for the IBM PCI SSA
adapter -- and possibly officially endorse it, at least that is the
usual process. There are at least two well-known SCSI device driver
authors in the Linux community who are more than keen to write the
device driver. I will get loan hardware and the device driver
development toolkit in time. The loan contract will only be valid for
90 days, though, after which we will probably need to return the loan
hardware. Donations are more than welcome!

I also contacted Pathlight Technology Inc.. Pathlight offers a single
loop PCI SSA adapter which is simpler and probably cheaper than the
IBM adapter. Pathlight is also going to support us but they currently
have a problem with releasing the driver source code because it
contains some parts which are considered confidential.

SSA documentation is available for free on the SSA Industry
Association's Documentation and Standards page or from the Symbios
Logic, Inc. anonymous FTP server.

A couple of prerequisites have to be fulfilled prior to getting the
SSA device driver reasonably done. A major difference of SSA compared
to external RAID boxes is that all disks are seen by the operating
system individually. This currently limits us to 16 SCSI/SSA disks due
to the major/minor device number scheme in the Linux kernel. (It
appears the current development trend is to go for a 64 bit dev_t
value which would allow us to use at least 16 bits for the minor
device number.)

Remark: There is also a PCI SSA RAID adapter from IBM which does RAID
levels 0 (striping), 1 (mirroring) and 5 (striping with parity) in
hardware. The current adapter firmware doesn't support more than one
adapter in a loop, however, which makes it unusable for multi-host
attachments. This could change before too long. RAID 5 organized
bunches of disks are presented to the operating system as single
entities, and the adapter can group up to 14 plus 1 disks in a RAID 5
configuration. Since the biggest SSA disk is currently 9.1 GB, this
sums up to 14 times 9.1 GB = 127.4 GB as a single entity. Please keep
in mind that due to parity sum calculations which are needed for every
write operation, mirrored setups (RAID level 1) are usually faster on
writes than RAID level 5.

According to the SCSI development folks, the current Linux SCSI mid
layer code is too slow to handle SSA data rates efficiently. This is a
known problem which will hopefully be fixed as soon as there is a SSA
device driver available.

Design Request: I herewith ask the Linux SCSI developers/maintainers
to fix this as soon as possible, as well as re-design the disk and
device numbering scheme to support more than 16 SCSI disks.

The SSA driver will also need to support SSA Target Mode (see section
Non-IP Heartbeat).

The Vicom SLIC

Another way to attach SSA disks to a Linux machine is to use the so-
called Serial Loop Interface Card (SLIC) built by Vicom Systems, Inc..
This device is also offered by IBM with the feature code #7190. The
SLIC basically converts a F/W/D SCSI bus to a single SSA loop which
can have up to 32 disks. The SLIC presents the disks to the operating
system as 32 SCSI LUNs (logical units) on a single SCSI ID (remember
we still have the 16 SCSI disks limitation inside Linux). The good
news is that as long as the SLIC is the only SCSI target on the SCSI
bus, there is no bus arbitration overhead. This results in a maximum
sustained throughput of 18 MByte/s. The current SLIC supports only one
SSA initiator per loop which is not good for a twin-tailed
configuration but the requirement for multiple-initiator is recognized
and will eventually be fulfilled. There will also be Ultra-SCSI
versions which will sort of double the throughput.

Pathlight Technology Inc.

Pathlight who was mentioned before is also going to release several
SCSI-to-SSA converter tools. At NAB 97, they announced some
interesting new products: a SSA 16 port hub is ready and in
production, SSA Network Agent which interconnects SSA and Ultra Wide
SCSI and Ethernet in one box and enables SCSI and SSA initiators and
targets to transfer data between each other. Also they announced a new
small black box called "Magic" that extends the SSA cable length to
100 meters (300 feet) on twisted pair copper cable.

HTH
Mark taylor

Mark Taylor wrote:
> However ref: http://www.vergenet.net/linux/redund...y-HOWTO-7.html
>
> Linux SSA Device Driver
>
> There is no Linux SSA device driver today, however IBM Systems Storage
> Division (SSD) will support us to get one written for the IBM PCI SSA
> adapter -- and possibly officially endorse it, at least that is the
> usual process. There are at least two well-known SCSI device driver
> authors in the Linux community who are more than keen to write the
> device driver. I will get loan hardware and the device driver
> development toolkit in time. The loan contract will only be valid for
> 90 days, though, after which we will probably need to return the loan
> hardware. Donations are more than welcome!
>
> I also contacted Pathlight Technology Inc.. Pathlight offers a single
> loop PCI SSA adapter which is simpler and probably cheaper than the
> IBM adapter. Pathlight is also going to support us but they currently
> have a problem with releasing the driver source code because it
> contains some parts which are considered confidential.
>
> SSA documentation is available for free on the SSA Industry
> Association's Documentation and Standards page or from the Symbios
> Logic, Inc. anonymous FTP server.
>
> A couple of prerequisites have to be fulfilled prior to getting the
> SSA device driver reasonably done. A major difference of SSA compared
> to external RAID boxes is that all disks are seen by the operating
> system individually. This currently limits us to 16 SCSI/SSA disks due
> to the major/minor device number scheme in the Linux kernel. (It
> appears the current development trend is to go for a 64 bit dev_t
> value which would allow us to use at least 16 bits for the minor
> device number.)
>
> Remark: There is also a PCI SSA RAID adapter from IBM which does RAID
> levels 0 (striping), 1 (mirroring) and 5 (striping with parity) in
> hardware. The current adapter firmware doesn't support more than one
> adapter in a loop, however, which makes it unusable for multi-host
> attachments. This could change before too long. RAID 5 organized
> bunches of disks are presented to the operating system as single
> entities, and the adapter can group up to 14 plus 1 disks in a RAID 5
> configuration. Since the biggest SSA disk is currently 9.1 GB, this
> sums up to 14 times 9.1 GB = 127.4 GB as a single entity. Please keep
> in mind that due to parity sum calculations which are needed for every
> write operation, mirrored setups (RAID level 1) are usually faster on
> writes than RAID level 5.
>
> According to the SCSI development folks, the current Linux SCSI mid
> layer code is too slow to handle SSA data rates efficiently. This is a
> known problem which will hopefully be fixed as soon as there is a SSA
> device driver available.
>
> Design Request: I herewith ask the Linux SCSI developers/maintainers
> to fix this as soon as possible, as well as re-design the disk and
> device numbering scheme to support more than 16 SCSI disks.
>
> The SSA driver will also need to support SSA Target Mode (see section
> Non-IP Heartbeat).
>
> The Vicom SLIC
>
> Another way to attach SSA disks to a Linux machine is to use the so-
> called Serial Loop Interface Card (SLIC) built by Vicom Systems, Inc..
> This device is also offered by IBM with the feature code #7190. The
> SLIC basically converts a F/W/D SCSI bus to a single SSA loop which
> can have up to 32 disks. The SLIC presents the disks to the operating
> system as 32 SCSI LUNs (logical units) on a single SCSI ID (remember
> we still have the 16 SCSI disks limitation inside Linux). The good
> news is that as long as the SLIC is the only SCSI target on the SCSI
> bus, there is no bus arbitration overhead. This results in a maximum
> sustained throughput of 18 MByte/s. The current SLIC supports only one
> SSA initiator per loop which is not good for a twin-tailed
> configuration but the requirement for multiple-initiator is recognized
> and will eventually be fulfilled. There will also be Ultra-SCSI
> versions which will sort of double the throughput.
>
> Pathlight Technology Inc.
>
> Pathlight who was mentioned before is also going to release several
> SCSI-to-SSA converter tools. At NAB 97, they announced some
> interesting new products: a SSA 16 port hub is ready and in
> production, SSA Network Agent which interconnects SSA and Ultra Wide
> SCSI and Ethernet in one box and enables SCSI and SSA initiators and
> targets to transfer data between each other. Also they announced a new
> small black box called "Magic" that extends the SSA cable length to
> 100 meters (300 feet) on twisted pair copper cable.
>
> HTH
> Mark taylor
>
>
Yaaaaay!

I have an F50 running FC6 that could use the installed disk space. It
is a very adequate machine to run this OS, but I am doing some syslog
collection with it and this driver would be da bomb.

Please keep this group posted with any details.

SG