I'm sponsoring the following fasttrack for Jim Dunham. Requested binding
is Patch. I believe this case qualifies for self-review. If anyone
disagrees, I'll convert it and set the timer.
- John
Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI
This information is Copyright 2009 Sun Microsystems
1. Introduction
1.1. Project/Component Working Name:
iSCSI Target Daemon's SCSI-3 PGR data needs to follow ZVOLs
1.2. Name of Document Author/Supplier:
James Dunham
1.3. Date of This Document:
03/10/09
2. Project Summary
2.1. Project Description:
SCSI-3 PGR (Persistent Group Reservation) data must follow the ZVOL that
is the backing store for the SCSI-3 LUN. Since ZVOLs are exportable from
one host, importable on another host, PGR data must follow.
The effort provides a single SCF option to support a PGR_basedir, a
directory which has the means to follow a ZFS Storage Pool mount point,
as it is exported and imported between nodes.
2.2. Risks and Assumptions:
SCSI-3 PGR data in clustered storage nodes, consisting of two or more
nodes, need to assured this SCF entry is consistent set between nodes.
3. Business Summary
N/A
4. Technical Description:
4.1. Details:
The current iSCSI Target Daemon stores SCSI-3 PGR data to the directory
/etc/iscsi.
This 'pins' the PGR data to a single Solaris host, even though a ZVOL or
ZVOLs can be exported from the current node, imported on another node.
There is no room in the ZVOL itself, as the iSCSI Client own 100% of the
blocks in a ZVOL. There is little remaining space in the 'iscsi-options'
ZVOL property, as other iSCSI properties consume ~1000 bytes, of a 2K
limit, and PGR data can be 1000s or 10,000s of bytes in size, depending
on the number of nodes in a clustering solution.
The solution is to provide a PGR base directory, specified in the iSCSI
Target Daemon's SCF data.
svccfg -s iscsitgt setprop iscsitgt/PGR-basedir = \
astring: "<some ZVOL related pathname>"
4.1.1 Interfaces
iscsitgt/PGR-basedir
The PGR base directory is a pathname specification that contains one or
more ZFS filesystem mount points, a filesystem which contains one or
more ZVOLs, ZVOLS which have the following property set:
zfs set shareiscsi={on|off} <pool-name>/<zvol-name>
4.2. Bug/RFE Number(s):
6794624 SCSI-3 PGR data for LUs whose backing store is a ZVOL, need to
persist data in a ZVOL attributes
4.3. In Scope:
For OpenSolaris single node, not setting the SCF property will retain
current behavior, of storing SCSI-3 PGR in /etc/iscsi
For OpenSolaris multinode, setting the SCF property to a "/", or some
other ZFS mount point, will provide a default, or alternate means for
a ZFS storage pool filesystem mount point to be set.
4.4. Out of Scope:
This functionality has no impact on COMSTAR or its support of
SCSI-3 PGR
4.5. Interfaces:
svccfg(1m) ? service configuration facility l
libscf(3LIB) ? service configuration facility library (man pages ...
4.6. Doc Impact:
The iSCSI Target man page will be updataed to document this
functionality.
6815596 iscsitgtd(1M) needs to be updated to cover PGR base directory
option.
4.7. Admin/Config Impact:
Awareness of this setting, and how it relates SCSI-3 PGR data and ZVOLs
4.8. HA Impact:
For OpenSolaris, this setting will allow SCSI-3 PGR data to follow ZVOLs
and their storage pools
4.9. I18N/L10N Impact:
N/A
4.10. Packaging & Delivery:
Part of SUNWiscsitgt
4.11. Security Impact:
iSCSI Target Daemon is a root privileged Solaris Daemon
4.12. Dependencies:
The changes are all project private
5. Reference Documents:
6794624 SCSI-3 PGR data for LUs whose backing store is a ZVOL, need to
persist data in a ZVOL attributes
6. Resources and Schedule:
6.1. Projected Availability:
ASAP
6.2. Cost of Effort:
1 week
6.3. Cost of Capital Resources:
N/A
6.4. Product Approval Committee requested information:
6.4.1. Consolidation or Component Name:
ON
6.4.3. Type of CPT Review and Approval expected:
BugFix or RFE
6.4.4. Project Boundary Conditions:
N/A
6.4.5. Is this a necessary project for OEM agreements:
No
6.4.6. Notes:
6.4.7. Target RTI Date/Release:
SNV_111
6.4.8. Target Code Design Review Date:
03/04/09
6.4.9. Update approval addition:
N/A
6.5. ARC review type:
SelfReview
6.6. ARC Exposure:
open
6.6.1. Rationale:
7. Prototype Availability:
7.1. Prototype Availability:
N/A
7.2. Prototype Cost:
N/A
