I'm new to this forum, so please excuse me if i err in some way. This is a complex question and as such requires a bit of explanation. This problem evolved from musings of adding an OptiBay enclosed SSD to my MacBook.
The ultimate goal of this project is two have my system files mirrored across two disk (HDD & SSD) whilst recognized as one logical partition by OSX. I want to read and write to just the SSD (since it's the fastest), and then have any changes synced two a mirror on the HD. SSD may be removed from time to time, so i want OSX to be able to boot from the mirror whenever the SSD is not found at boot (hence the single logical partition).
- My current hypothesis as to how i might accomplish this is via a Software RAID 0. It's not that simple though, since a plain RAID 0 between the two disks would be impractical. The RAID would be limited by the read/write speed of the HD, thus negating the speed boost of the SSD.
- How can set it up as a RAID 0, but only r/w to/from the SSD (from the system's perspective) and let the RAID handle syncing the data?
- What would i need, in terms of software, to set up that RAID?
- An alternate method might be to set up two independent partitions (one on each disk), identify the SSD as the start up disk, and run a script (with lowered priority) that syncs the SSD partition with the former partition.
- How would i go about writing such a script? What language would it have to be in to run with the smallest resource consumption?
- How would i make the mirror HDD partition hidden during normal operations, but automatically boot from it when the SSD is not found?
- Any solutions must be a software solution and/or use hardware that would fit inside the MacBook's case
- The mirror partition on the HDD does not cover the whole disk. Other partitions on the HDD must be accessible at all times to the OS.
- The same goes for the SSD except for when it's removed.
- Syncing between disks should not create any appreciable latency.
- Restricted to the capabilities of OSX 10.6.
Thanks a bunch in advance for any help that can be provided!