I’ve discovered a way to use a file on a computer as a FireWire Harddisk for another computer. This is a handy way to work with older Apple computers because it’s way easier than burning CD’s or using a read FW HDD.

The setup is not that complicated but still there is some to do.

And in advance: Only HDD’s are emulated. So you can’t use CD images (or at least not directly, for Mac OS X I’ve covered that below) and write access to the disk image is required (shouldn’t be a hurdle).

Requirements

• Computer with a FireWire interface (of course)
• Linux with Kernel 3.4+ and the required module (firewire_sbp2)
• targetcli to easily configure it

I’ve tested Ubuntu 14.04 and Fedora 20 on my MacBook Pro (2009): – Ubuntu’s targetcli is not able to handle FireWire – Fedora 20 can be used from Live CD/USB and targetcli supports firewire

After this I’ve stopped searching for more distributions. And all instructions are for Fedora 20, I only used the Live mode but shouldn’t be different if installed.

Setup

• Boot into Fedora 20
• Ensure you have a network connection to install packages
• All commands are executed as root, so do a sudo in front of each command or login / gain access to root
• Install targetcli: yum install targetcli
• Create a disk image or copy one, important: the file must be writeable
• Use targetcli to set everything up

Disk images

Fedora seem to not have HFS+ write support, but since a writeable file is required I added a new ExFat partition (with Disk Utility on OS X) to my system and installed the driver: yum install fuse-exfat.

I’ve mounted the partition by hand: mount /dev/sha4 /mnt/images.

It seems that targetcli does not work with files and paths which have spaces or the equal sign in it! You have to avoid them, also maybe in volume names because if automatically mounted they are used in the path.

Since only hard disks are emulated a cd imageg can still added but the computer will not boot from it (usually) becuase booting from HDD and CD are handeled differently.

But for OS X DVD’s it’s easy to convert them:

• Using Disk Utility on OS X create a new blank disk image
  • The image must be, of course, big enough to hold the DVD, mount the DVD and use the finder to get the size
    but don’t make the image too big because it will be stored uncompressed
  • Format: “Mac OS X Extended (Journaled)”, maybe without journaling for old OS X
  • Partitions: “Single partiotion – GUID Partition map” for Intel Macs and
    “Single partition – Apple Partition Map” for PowerPC Macs (the one you want to boot not the “server”)
• Copy all files form the DVD to the Image
• Eject both
• Use the image

targetcli Basics

All commands can either be executed in the interactive targetcli shell or as a parameter to targetcli (for perforimg a single action).

In the interactive shell you can either walk around in the tree and perform actions there or pass the working directory as the first argument, examples

# "walk around"
cd /backstores
ls
# "as parameter"
/backstores ls

If not using the interactive shell you of course have always to use the second method. All commands here are given as direct calls to make them easier to batch.

Usage

Add a disk image: targetcli /backstores/fileio create name=10.4-PPC file_or_dev=/mnt/images/10.4-PPC.dmg. The name parameter is used to reference to this entry furthermore, feel free to add as many images as you want.

To create the FireWire system you have to figure out your “WWN” with targetcli /sbp info and then create it targetcli /sbp create eui.64b9e8fffecd98ca.

Add the image to firewire with: targetcli /sbp/eui.64b9e8fffecd98ca/luns create /backstores/fileio.10.4-PPC. You can add multiple images and all of them will be available.

Enable the FireWire system: targetcli /sbp/eui.64b9e8fffecd98ca enable.

With targetcli / ls you can get a listing of your current setup, here is mine:

o- / ............................................................................... [...]
  o- backstores .................................................................... [...]
  | o- block ........................................................ [Storage Objects: 0]
  | o- fileio ....................................................... [Storage Objects: 1]
  | | o- 10.4-PPC ............... [/mnt/images/10.4-PPC.dmg (2.8GiB) write-back activated]
  | o- pscsi ........................................................ [Storage Objects: 0]
  | o- ramdisk ...................................................... [Storage Objects: 0]
  o- iscsi .................................................................. [Targets: 0]
  o- loopback ............................................................... [Targets: 0]
  o- sbp .................................................................... [Targets: 1]
  | o- eui.64b9e8fffecd98ca ........................................................ [...]
  |   o- luns .................................................................. [LUNs: 1]
  |     o- lun0 ............................. [fileio/10.4-PPC (/mnt/images/10.4-PPC.dmg)]
  o- vhost .................................................................. [Targets: 0]

Now it’s time to connect the FireWire cable to the two machines and use it.

Here you can see my boot selection screen with the FireWire image. And yes, it’s no FireWire symbol but it still is one and works.

And a screenshot where you can see my attatched disk image.

With targetcli /sbp/eui.64b9e8fffecd98ca/luns delete 0 you can remove the 1st image from FireWire. You should add or remove luns only when the cable is not connected or the other computer is turned off. The images in ‘/backstores/fileio/…’ does not have to be removed with the lun.

On OS X and iOS the following table shows you the the size of the types:

char       8 bit
short     16 bit
int       32 bit
long      system size
long long 64 bit

So, on 32bit OS X long is 32 bit, on 64bit OS X it’s 64 bit (unsure for iOS).

NSInteger has always the size of an pointer.

Often asked: “Use int or NSInteger?”. Answer: use NSInteger for pointers, ok usually you should use the pointer type itself, and for everything else use the size you require.

If you want exactly 8 bits, use int8_t for sigend or uint8_t for unsigned, for an integer which has at least those bits, use (u)int_least8_t (analogue for 16/32/64 bits).

Performance: you can use (u)int_fast8_t for the fastest type, which can hold (u)int_8_t. But since (u)int_leastY_t and (u)int_fastY_t are defined as (u)intY_t on OS X and iOS it should make no difference. I use the direct types for when all the bits are used, and the fast types when I don’t use exactly but less bits.

At last: don’t forget the LL or ULL suffix for 64bit constants (you can use (U)INT64_C(num) for always the correct suffix, also for 8/16/32), and the “%lld” in a formatted string for 64bit variables.
(example: NSLog(@"number: %lld", 1LL << 48);)

If you have more information or maybe corrections, please post a comment.

It’s desigend for servers, which are no mail servers, and only sends logs, notices and such things. So all other software (may be scripts, used from the web-server) have to use a SMTP server for outgoing mail (e.g. forum).

It can be configred that when sendmail is invoked by a user, that all those mails are going to another address. (the users which calls sendmail is important, not the destination).

example configuration:
[default]
to = "destination@address"
from = "sender@address"
subject = "[Server] [To: %TO%] %SUBJECT%"

You can add more entries in that form, which usernames instead of “default”, in that case all mails sent by that user will be send to the specified address.

The options in detail:

• disabled, optional, defaults to false, if true no mail will be sent (for that user)
• to, required, the destination
• host, optional, the destination host, if omitted the MX record of the to address will be used
• subject, optional, the subject, defaults to “%SUBJECT%” (placeholders: %SUBJECT% the original subject, %TO% the list of original recipients)
• from optional, the sender address, default to “user@hostname”

Files:

• /etc/zeromail.conf
• /usr/sbin/sendmail

You may have problems after uninstalling all MTA software, because some software (e.g. logcheck) requires an installed MTA. I’ve fixed that problem by installing an dummy deb-package, which (says that it) provides an MTA.

This is the way I’m using it on my server and a proof of concept.

Some more explanations in the source.

Download:

zeromailer 0.3 (7.2 KiB, 15. June 2010)