[1] Mounting NFS on Solaris 10 and later

With a relevant entry in /etc/vfstab, the general expectation is that Solaris automatically mounts the NFS shares upon a system reboot. However users may find that NFS shares are not being auto-mounted on some of the systems running the latest update of Solaris 10 or 11. One reason for this behavior could be the use of the Secure By Default network profile, which was introduced in Solaris 10 11/06. When this networking profile is in use, numerous services including the NFS client service are disabled. For the automounting of NFS shares, we will need the NFS client service running.

The fix is to enable NFS client service along with its dependencies.

# svcs -a | grep nfs\/client
disabled       Jan_17   svc:/network/nfs/client:default

# svcadm  enable -r svc:/network/nfs/client

# svcs -a | grep nfs\/client
online         Jan_20   svc:/network/nfs/client:default

On a similar note, if you want all default services to be enabled as they were in previous Solaris releases, run the following command as privileged user. Then use svcadm(1M) to disable unwanted services.

# netservices open

To switch back to the secure by default profile, run:

# netservices limited

[3] Permission denied error when changing a password

An attempt to change the password for a local user 'XYZ' fails with Permission denied error.

# passwd XYZ
New Password: ********
Re-enter new Password: ********
Permission denied

# grep passwd /etc/nsswitch.conf
passwd: files ldap

Users have the flexibility to include and access password information in/from multiple repositories such as files and nis or ldap. Per the man page of passwd(1), when a user has a password stored in one of the name services as well as a local files entry, the passwd command tries to update both. It is possible to have different passwords in the name service and local files entry. Use passwd -r to change a specific password repository.

Hence the fix is to use the -r option in this case to ignore the nsswitch.conf file sequence and update the password information in local /etc files — /etc/passwd and /etc/shadow files.

# passwd -r files XYZ
New Password: ********
Re-enter new Password: ********
passwd: password successfully changed for oracle

# prstat -p 39235

   PID USERNAME  SIZE   RSS STATE   PRI NICE      TIME  CPU PROCESS/NLWP      
 39235 psft     3585M 3320M sleep    59    0   2:23:11 0.0% java/257

# prstat -mp 39235

   PID USERNAME USR SYS TRP TFL DFL LCK SLP LAT VCX ICX SCL SIG PROCESS/NLWP  
 39235 psft     0.0 0.0 0.0 0.0 0.0  87  13 0.0   0   0   1   0 java/257


# ptime -mp 39235

real 428:31:25.902644700
user  2:06:32.283801209
sys     16:37.056999418
trap        2.250539737
tflt        0.000000000
dflt        2.018347218
kflt        0.000000000
lock 96013:52:37.184929717
slp  14349:50:02.286168683
lat      3:11.510473038
stop        0.002468763

[5] ZFS : metaslab utilization

ZFS divides the space on each device (virtual or physical) into a number of smaller, manageable regions called metaslabs. Each metaslab is associated with a space map that holds information about the free space in that region by keeping tracking of space allocations and deallocations.

The following sample outputs show that a virtual device, u01, made up of two physical disks has 139 metaslabs. The number of segments and free/available space in each metaslab is also shown in those outputs.

# zpool list u01
NAME   SIZE  ALLOC  FREE  CAP  DEDUP  HEALTH  ALTROOT
u01   1.09T   133G  979G  11%  1.00x  ONLINE  -

# zpool status u01
  pool: u01
 state: ONLINE
  scan: none requested
config:

        NAME                       STATE     READ WRITE CKSUM
        u01                        ONLINE       0     0     0
          mirror-0                 ONLINE       0     0     0
            c0t5000CCA01D1DD4A4d0  ONLINE       0     0     0
            c0t5000CCA01D1DCE88d0  ONLINE       0     0     0

errors: No known data errors

# zdb -m u01

Metaslabs:
        vdev          0   ms_array         27
        metaslabs   139   offset                spacemap          free      
        ---------------   -------------------   ---------------   -------------
        metaslab      0   offset            0   spacemap     30   free    4.65M
        metaslab      1   offset    200000000   spacemap     32   free     698K
        metaslab      2   offset    400000000   spacemap     33   free    1.25M
        metaslab      3   offset    600000000   spacemap     35   free     588K
 ..
 ..
        metaslab     62   offset   7c00000000   spacemap      0   free       8G
        metaslab     63   offset   7e00000000   spacemap     45   free    8.00G
        metaslab     64   offset   8000000000   spacemap      0   free       8G
 ...
 ...
        metaslab    136   offset  11000000000   spacemap      0   free       8G
        metaslab    137   offset  11200000000   spacemap      0   free       8G
        metaslab    138   offset  11400000000   spacemap      0   free       8G

# zdb -mm u01   

Metaslabs:
        vdev          0   ms_array         27
        metaslabs   139   offset                spacemap          free      
        ---------------   -------------------   ---------------   -------------
        metaslab      0   offset            0   spacemap     30   free    4.65M
                          segments       1136   maxsize    103K   freepct    0%
        metaslab      1   offset    200000000   spacemap     32   free     698K
                          segments         64   maxsize    118K   freepct    0%
        metaslab      2   offset    400000000   spacemap     33   free    1.25M
                          segments        113   maxsize    104K   freepct    0%
        metaslab      3   offset    600000000   spacemap     35   free     588K
                          segments        109   maxsize   28.5K   freepct    0%
 ...
 ...

What is the purpose of this topic? Just to introduce the ZFS debugger, zdb (check the man page zdb(1M)) to the power-users who would like to dig a little deep to find answers to tough questions such as if a ZFS filesystem is fragmented.

Keywords: ZFS zdb metaslab "space map"

login: root
Password: ********
Roles can not login directly

# rolemod -K type=normal root

/* assign root role to user 'giri' */
# usermod -R root giri

# roles giri
root

/* remove the role from user 'giri' */
# usermod -R "" giri
#

[7] Large volume sizes (> 2 TB), and maximum size of UFS filesystem

As per the Solaris System Administration Guide, the maximum size of a UFS filesystem is ~16 TB.

To create a UFS file system greater than 2 TB, use EFI disk label. The EFI label provides support for physical disks and virtual disk volumes that are greater than 2 TB in size. Refer to the disk management section in Solaris System Administration Guide to find out the advantages and limitations of EFI.

Note that ZFS labels disks with an EFI label when creating a ZFS storage pool (zpool). And users in general need not be too concerned about the maximum size of a ZFS filesystem as it is several times larger than the maximum size supported by the UFS filesystem.

                                                                                Solaris PowerTOP version 1.3

Idle Power States       Avg     Residency                                                 Frequency Levels
C0 (cpu running)                (0.1%)                                                     500 Mhz        0.0%
C1                      4.7ms   (99.9%)                                                    800 Mhz        0.0%
                                                                                           933 Mhz        0.0%
                                                                                          1067 Mhz        0.0%
                                                                                          1200 Mhz        0.0%
                                                                                                 ..
                                                                                                 ..
                                                                                          3200 Mhz        0.0%
                                                                                          3333 Mhz        0.0%
                                                                                          3467 Mhz        0.0%
                                                                                          3600 Mhz        100.0%

Wakeups-from-idle per second: 109818.7  interval: 5.0s
no power usage estimate available

Top causes for wakeups:
94.4% (103630.7)               sched :  <xcalls> unix`dtrace_sync_func
 3.1% (3352.8)              OPMNPing :  <xcalls> unix`setsoftint_tl1
 1.1% (1155.6)                 sched :  <xcalls> unix`setsoftint_tl1
 0.4% (401.2)               <kernel> :  genunix`pm_timer
 0.3% (317.0)                  sched :  <xcalls> 
 0.2% (251.8)               <kernel> :  genunix`lwp_timer_timeout
 0.2% (204.4)                  sched :  <xcalls> unix`null_xcall
 0.1% (100.2)               <kernel> :  genunix`clock
 0.1% ( 65.6)               <kernel> :  genunix`cv_wakeup
 0.0% ( 50.2)               <kernel> :  SDC`sysdc_update
 0.0% ( 46.8)            <interrupt> :  mcxnex#0 
 0.0% ( 39.6)                   opmn :  <xcalls> unix`setsoftint_tl1
 0.0% ( 36.6)                   opmn :  <xcalls> 
 0.0% ( 36.4)                   opmn :  <xcalls> unix`vtag_flushrange_group_tl1
 0.0% ( 21.6)            <interrupt> :  ixgbe#0
 ...
 ...

Suggestion: enable CPU power management using poweradm(1m)

Q - Quit R - Refresh (CPU PM is disabled)

Labels: nfs powertop solaris zfs f40 tips

Posted by: Giri Mandalika.    # 10:21 PM 0 comments.     Tweet

Bond prices and bond yields are inversely related — rising bond prices means lower yields, and falling bond prices imply higher yields.

When sold initially at auction by the US Treasury department, treasury notes or bonds will have a fixed face value and fixed interest rate. In the context of treasury bonds, the interest rate is usually referred as coupon rate, coupon percent rate or simply coupon.

Similar to stocks, bonds are resold on the open market or secondary market. Demand for those treasury bonds may push the price higher and the yield lower. The reason for the lower yield being upon maturity, treasury pays back just the face value along with the pre-determined interest rate. The current yield for any treasury bond can can be calculated as shown below.

                   Actual Annual Interest
   Current yield = ---------------------- * 100
                    Current Market Value

For example, if a treasury bond with a face value of $100 and an interest rate 3% was sold at a premium price for $101 due to demand, the current yield will be (3/101) * 100 = 2.97%

Implication of Treasury Yields:

Listed below are some high-level implications of the rising or falling treasury yields.

Rise in treasury yields may:

• push the interest rate upwards on fixed-length mortages and loans with similar lengths. In other words, rise in treasury yields hurt borrowers by driving up the borrowing costs making longer-term loans such as housing, car loans less affordable. On the other hand, savers benefit by the rise in interest rates.

• pose a threat to Governments with huge national debt by increasing the interest payments on that debt.

• increase the value of the world's reserve currency — the US dollar as of today, which could attract foreign investment. As the returns on US dollar increase, the demand for US dollar grows worldwide.

• negatively impact stock markets as investors may move out of those risky assets to less risky assets such as bonds

• negatively impact precious metals such as Gold. The general theory is that since the returns on precious metals mainly depend on the demand for those metals, rise in bond yields and a subsequent strengthned US dollar make investing in precious metals less attractive.

Drop in treasury yields usually will have inverse effect of the rise in treasury yields. For example, drop in treasury yields may lead to decreased interest rates, which in turn may encourage borrowing and the resulting cash flow can result in real estate boom on the positive side, and can cause the inflation to go up on the negative side. Inflation is the rise in the prices of goods and services over time. Rise in interest rates in a inflation ridden nation may make things worse.

Note that the impact can be felt when there is a sudden and noticeable movement in yields in either direction. Once stabilized, people may get used to the new normal, and some of the things may go back to the way there were. For example, sudden upward surge in treasury yields may drive investors away from Gold - but once the knee-jerk reaction subsides, investors may return and continue trading Gold. After all, Gold is a precious metal with lots of demand worldwide.

Source: various including Investopedia

Labels: Finance Treasury Bonds Yields T-Bonds T-Notes Coupon

Posted by: Giri Mandalika.    # 11:50 PM 0 comments.     Tweet