I am submitting the following as a fast-track on behalf of myself, with
a timeout set for 06/16/2009. Patch/micro binding is requested.
-------------
1. Introduction
1.1. Project/Component Working Name:
EOF UCB Device Names
1.2. Name of Document Author/Supplier:
Author: Jerry Gilliam
1.3. Date of This Document:
06/05/2009
1.4. Name of Major Document Customer(s)/Consumer(s):
1.4.1. Solaris PAC
1.4.2. PSARC
1.4.3. Chris Armes
1.4.4. Solaris Sustaining
1.5. Email Aliases:
1.5.1. Responsible Manager: Michael.Pogue at sun.com
1.5.2. Responsible Engineer: Jerry.Gilliam at sun.com
1.5.3. Marketing Manager:
1.5.4. Interest List: Sriram.Popuri at sun.com, Chris.Horne at sun.com,
Jan.Setje-Eilers at sun.com
2. Project Summary
2.1. Project Description:
EOF of UCB device names
3. Business Summary
3.1. Problem Area:
Performance issues related to boot and device naming with ucblinks
3.2. Market/Requester:
Escalations by Bloomberg Financial and other customers with
large installations
3.2 Details
A large configuration was simulated with a pseudo driver used to
configure
16k disk devices. Devfsadm required 25 minutes in this configuration
and
ucblinks 5 minutes on top of that. The number of /dev/[r]sd names
generated
by ucblinks alone was 262k and since these names are at the top /dev
level, greatly contribute to system sluggishness. For example, > 5
minute
logins. With the /dev/[r]sd names removed, system responsiveness was
as expected.
4. Technical Description:
4.1. Details:
Since committed interfaces can only be obsoleted in a minor release
and a way to provide relief to existing customers is required,
a two-step process is proposed.
In the current minor release, complete the EOF, removing ucblinks,
and provide a note in the next available release with intention
to obsolete said interfaces.
For patch/macro release relief, it is proposed to introduce a
service to manage ucblinks: svc:/system/ucb-device-names. With
a default of disabled, the out-of-the box experience will be
improved with no ucblinks generated and existing ucb compatible
names removed. Enabling the service will generate ucb compatible
names by running ucblinks, for any customer who desires this
compatibility to be retained.
The set of UCB compatible names is:
UCB link name Standard name Device type
/dev/[r]fd%d /dev/[r]diskette fd floppy drives
/dev/[r]sr%d /dev/[r]dsk/* sd/atapi cdrom drives
/dev/[r]sd%d /dev/[r]dsk/* sd disk drives
/dev/[r]n%d /dev/rmt/* st tape drives
Support for the following is removed:
xd, xt, xy
The following appear to be ucb compatible names, with code within
ucblinks building them, but devfsadm builds them also so that
removing the ucblinks code will not affect these names:
/dev/fb%d /dev/fbs/* framebuffers
/dev/tty[d]%d /devices link serial devices
/dev/tty[a-z] /devices link serial devices
4.2. Bug/RFE Number(s):
6785226 devfsadm -C does not help to clean up the device tree.
4.5 Interfaces:
Minor release:
--------------
/usr/ucb/ucblinks(1B) Obsolete ucblinks end-of-feature
/dev/[r]fd%d Obsolete floppy device /dev names
/dev/[r]sr%d Obsolete cdrom /dev names
/dev/[r]sd%d Obsolete disk /dev names
/dev/[r]n%d Obsolete tape /dev names
Patch/Macro release:
--------------------
svc:/system/ucb-device-names Uncommitted service,
disabled by default
/lib/svc/method/ucb-device-names Proj. Priv. service method
/var/svc/manifest/system/ Proj. Priv. service manifest
ucb-device-names.xml
/usr/ucb/ucblinks(1B) -C Uncommitted ucblinks cleanup
The above patch/micro interfaces are not to be carried forward to the
minor release.
4.6. Doc Impact:
Minor release:
--------------
ucblinks(1B) man page to be removed.
Patch/Macro release:
--------------------
ucblinks(1B) man page update - suggested changes provided.
4.12. Dependencies:
There are no uses made of any /dev ucb compatible name within solaris.
The base install of OpenSolaris does not include /usr/ucb/ucblinks.
Some tools such as iostat generate device names using the
<driver><instance>
form, equivalent to a ucb device name. iostat does have an option (-n)
to generate reports using /dev/[rd]dsk device names. [2]
The same <driver><instance> names are logged along with device errors in
the system log and one way to map such names to the physical device has
been via the /dev ucb compatible name. Libdevinfo provides a method to
do the same mapping. This is used by iostat(1M) and is available for
usr
by other tools as needed. [3]
5. Reference Documents:
[1] PSARC/1996/430 iostat(1M) enhancements for device statistics
[3] PSARC/2006/519 Metadevice Names in iostat/vmstat Output
[2] PSARC/2000/310 libdevinfo devlinks interfaces
6. Resources and Schedule:
http://tethys.sfbay/export/ws/onnv-ucb-svc
6.5. ARC review type:
FastTrack
6.6. ARC Exposure:
open
SunOS/BSD Compatibility Package Commands ucblinks(1B)
NAME
ucblinks - adds /dev entries to give SunOS 4.x compatible
names to SunOS 5.x devices
SYNOPSIS
/usr/ucb/ucblinks [-e rulebase] [-r rootdir] [-C]
|
svc:/system/ucb-device-names
DESCRIPTION
ucblinks creates symbolic links under the /dev directory for
devices whose SunOS 5.x names differ from their SunOS 4.x
names. Where possible, these symbolic links point to the
device's SunOS 5.x name rather than to the actual /devices
entry.
ucblinks does not remove unneeded compatibility links; these
must be removed by hand.
ucblinks should be called each time the system is
reconfiguration-booted, after any new SunOS 5.x links that
are needed have been created, since the reconfiguration may
have resulted in more compatibility names being needed.
In releases prior to SunOS 5.4, ucblinks used a nawk rule-
base to construct the SunOS 4.x compatible names. ucblinks
no longer uses nawk for the default operation, although
nawk rule-bases can still be specifed with the -e option.
The nawk rule-base equivalent to the SunOS 5.4 default
operation can be found in /usr/ucblib/ucblinks.awk.
The svc:/system/ucb-device-names service controls whether
|
the system runs ucblinks(1B) on reconfigure boot. When
|
enabled, ucblinks(1B) is run, both at that time and on
|
subsequent reconfiguration boots. When disabled, ucblinks(1B)
|
is run in clean-up (-C) and ucb device names will no longer
|
be reconstructed on reconfigure boot.
|
|
The svc:/system/ucb-device-names service is by default disabled.
|
EXAMPLES
|
|
Example 1: Querying the state of the service
|
|
# svcs system/ucb-device-names
|
STATE STIME FMRI
|
disabled 13:19:49 svc:/system/ucb-device-names:default
|
|
Example 2: Enabling the service
|
|
# svcadm enable system/ucb-device-names
|
|
Example 2: Enabling the service
|
|
# svcadm disable system/ucb-device-names
|
OPTIONS
-e rulebase Specify rulebase as the file containing
nawk(1) pattern-action statements.
-r rootdir Specify rootdir as the directory under which
dev and devices will be found, rather than
the standard root directory /.
|
-C Clean up /dev ucb compatible device names.
|
|
FILES
/usr/ucblib/ucblinks.awk sample rule-base for compatibil-
ity links
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWscpu |
|_____________________________|_____________________________|
SEE ALSO
devlinks(1M), disks(1M), ports(1M), tapes(1M), attributes(5)
