diff options
Diffstat (limited to 'sys/cam/ctl/README.ctl.txt')
| -rw-r--r-- | sys/cam/ctl/README.ctl.txt | 30 |
1 files changed, 3 insertions, 27 deletions
diff --git a/sys/cam/ctl/README.ctl.txt b/sys/cam/ctl/README.ctl.txt index b3b08f596e3b..dd38cb587ab7 100644 --- a/sys/cam/ctl/README.ctl.txt +++ b/sys/cam/ctl/README.ctl.txt @@ -43,12 +43,9 @@ Features: - Persistent reservation support - Mode sense/select support - Error injection support - - High Availability support (1) + - High Availability support - All I/O handled in-kernel, no userland context switch overhead. -(1) HA Support is just an API stub, and needs much more to be fully - functional. See the to-do list below. - Configuring and Running CTL: =========================== @@ -245,27 +242,6 @@ To Do List: another data structure in the stack, more memory allocations, etc. This will also require changes to the CAM CCB structure to support CTL. - - Full-featured High Availability support. The HA API that is in ctl_ha.h - is essentially a renamed version of Copan's HA API. There is no - substance to it, but it remains in CTL to show what needs to be done to - implement active/active HA from a CTL standpoint. The things that would - need to be done include: - - A kernel level software API for message passing as well as DMA - between at least two nodes. - - Hardware support and drivers for inter-node communication. This - could be as simples as ethernet hardware and drivers. - - A "supervisor", or startup framework to control and coordinate - HA startup, failover (going from active/active to single mode), - and failback (going from single mode to active/active). - - HA support in other components of the stack. The goal behind HA - is that one node can fail and another node can seamlessly take - over handling I/O requests. This requires support from pretty - much every component in the storage stack, from top to bottom. - CTL is one piece of it, but you also need support in the RAID - stack/filesystem/backing store. You also need full configuration - mirroring, and all peer nodes need to be able to talk to the - underlying storage hardware. - Code Roadmap: ============ @@ -365,11 +341,11 @@ This is a CTL frontend port that is also a CAM SIM. The idea is that this frontend allows for using CTL without any target-capable hardware. So any LUNs you create in CTL are visible via this port. +ctl_ha.c: ctl_ha.h: -------- -This is a stubbed-out High Availability API. See the comments in the -header and the description of what is needed as far as HA support above. +This is a High Availability API and TCP-based interlink implementation. ctl_io.h: -------- |