Using iSCSI for NAS-Based Backups??
First, let me say I cannot report success with this technique, but it seems promising enough that I thought I post what I've tried and maybe others can fill in the blanks.
While looking through the different options my NAS provides, I ran across iSCSI. The reason this intrigued me is that iSCSI would allow me to format the shared asset as a native HFS+ volume, meaning TM should use it like an external dirve!!
After some research it seems there are two halves to iSCSI, a server (the NAS) provides a "target." The client runs an "initiator" to connect to the target over the network. The target then shows up on the client as a raw disk volume. Disk utility would then be able to format the volume like any external disk drive.
First hiccup: Apple yanked the iSCSI initiator from the final release:( However, it seems that a company called Studio Network Solutions has made their iSCSI initiator for MacOSX available for free!
http://www.studionetworksolutions.com/products/product_detail.php?t=more&pi=11
And, from what I could read in their forums, it works with Leopard.
So, I proceeded to create a 750G iSCSI target on my NAS (running FreeNAS). I installed the SNS initiator on my Mac Pro (running Leopard). I connected to the target and, Voila!, the volume showed up in Disk Utility. I partitioned and formatted the volume as HFS+ and it showed on the Desktop. Just for giggles, I opened the TM pref pane and sure enough TM saw the volume!!
OK, before I back up, let's see how stable this combo is. So I tried dragging a 4G DVD image to the new volume to see how fast it was. Wow, pretty fast: faster than my local SATA disk (since the iSCSI target is really a raid0 stripe connected via GigE).
Now for the bad news: it hangs after a couple Gigs. Bummer.
OK, so let's try the other free NAS: Openfiler. I read on the SNS forums a few people reported success with Openfiler. So I brought up an old PC with Openfiler. Created a 2x500G RAID0 stripe and a target on the raid volume. I connected to the target from the Mac Pro, formatted the volume and started a copy. OK, looks better this time. Still VERY fast but, alas, it stops after 7.5G. This time the entire OS hangs, not just the Finder. I have to reboot the Mac Pro the hard way 😟
I have not had the time since yesterday to do any more experimenting. However, it seems promising enough to share. And since there were reports of success with the SNS initiator with Openfiler, I figured the experimenters here may come up with something I didn't.
The bottom line: if we can get iSCSI working with Leopard, we have a way to backup from multiple Mac's to a NAS using a fairly widely supported (on the NAS side at least) protocol. Oh, and if you combine it with some RAID and GigE it may actually be FASTER than backup up to FW, USB or even interal SATA.
Also, if it's not clear from the post above, experimenting hung my Mac Pro hard. Not good. This technique is not yet for the beginner, but for people with the resources to experiment.
Please report back in the thread if you get any further than I did with this technique.
Fingers crossed...
While looking through the different options my NAS provides, I ran across iSCSI. The reason this intrigued me is that iSCSI would allow me to format the shared asset as a native HFS+ volume, meaning TM should use it like an external dirve!!
After some research it seems there are two halves to iSCSI, a server (the NAS) provides a "target." The client runs an "initiator" to connect to the target over the network. The target then shows up on the client as a raw disk volume. Disk utility would then be able to format the volume like any external disk drive.
First hiccup: Apple yanked the iSCSI initiator from the final release:( However, it seems that a company called Studio Network Solutions has made their iSCSI initiator for MacOSX available for free!
http://www.studionetworksolutions.com/products/product_detail.php?t=more&pi=11
And, from what I could read in their forums, it works with Leopard.
So, I proceeded to create a 750G iSCSI target on my NAS (running FreeNAS). I installed the SNS initiator on my Mac Pro (running Leopard). I connected to the target and, Voila!, the volume showed up in Disk Utility. I partitioned and formatted the volume as HFS+ and it showed on the Desktop. Just for giggles, I opened the TM pref pane and sure enough TM saw the volume!!
OK, before I back up, let's see how stable this combo is. So I tried dragging a 4G DVD image to the new volume to see how fast it was. Wow, pretty fast: faster than my local SATA disk (since the iSCSI target is really a raid0 stripe connected via GigE).
Now for the bad news: it hangs after a couple Gigs. Bummer.
OK, so let's try the other free NAS: Openfiler. I read on the SNS forums a few people reported success with Openfiler. So I brought up an old PC with Openfiler. Created a 2x500G RAID0 stripe and a target on the raid volume. I connected to the target from the Mac Pro, formatted the volume and started a copy. OK, looks better this time. Still VERY fast but, alas, it stops after 7.5G. This time the entire OS hangs, not just the Finder. I have to reboot the Mac Pro the hard way 😟
I have not had the time since yesterday to do any more experimenting. However, it seems promising enough to share. And since there were reports of success with the SNS initiator with Openfiler, I figured the experimenters here may come up with something I didn't.
The bottom line: if we can get iSCSI working with Leopard, we have a way to backup from multiple Mac's to a NAS using a fairly widely supported (on the NAS side at least) protocol. Oh, and if you combine it with some RAID and GigE it may actually be FASTER than backup up to FW, USB or even interal SATA.
Also, if it's not clear from the post above, experimenting hung my Mac Pro hard. Not good. This technique is not yet for the beginner, but for people with the resources to experiment.
Please report back in the thread if you get any further than I did with this technique.
Fingers crossed...
Mac OS X (10.5)