How do you check the failed components in Symmetrix
Array?
Symcfg -sid 150 list -env_data -service_state failed
How do you check the failed disks in the Symmetrix Array?
Symdisk -sid XXXX list -failed
What is the purpose of Gate Keeper device?
Low-level I/O commands executed using SYMCLI are routed to
the Symmetrix array by a Symmetrix storage device that is specified as a
gatekeeper.
The gatekeeper device allows SYMCLI commands to retrieve configuration and status information from the Symmetrix array without interfering with normal Symmetrix operations.
The gatekeeper must be accessible from the host where the commands are being executed.
The gatekeeper device allows SYMCLI commands to retrieve configuration and status information from the Symmetrix array without interfering with normal Symmetrix operations.
The gatekeeper must be accessible from the host where the commands are being executed.
How many gate keeper devices are required per Array?
It depends on the Symmetrix management applications using in
management servers,
As per EMC recommendations 6 gatekeepers are required per management host using symcli
As per EMC recommendations 6 gatekeepers are required per management host using symcli
How to list hosts and their EMC registered software,
using Solutions Enabler?
Symcfg -sid XXXX list -applications
What is VCMDB and how do you take the backup?
The device masking database (VCMDB) holds device masking
records and typically resides on a 24 or 48 cylinder disk device..
Symmaskdb -sid XXXX backup -f filename
Symmaskdb -sid XXXX backup -f filename
How do you list the Hosts which are connected to
particular director port?
Symmaskdb -sid XXXX list database -dir XX -p X
How do you check the number of storage bays connected to
the system bay and number of disks in each storage bay?
Symcfg -sid XXXX list -env_data
How do check the devices which are not mapped and masked?
Symdev -sid 4282 list dev -noport
How do you check the devices which are mapped to FA but
not masked to any host?
Symmaskdb -sid 123 list no_assignment -dir ALL -p ALL
How do you check the login hosts in the Symmetrix Array?
Symmask -sid 4282 list logins
How to display and set the Symmetrix metrics?
Symcfg -sid XXXX -SA all list -v
Set Symmetrix MatricName=MatricValue
Set Symmetrix MatricName=MatricValue
How do you check the configured environmental variables?
Symcli -def
Can windows, Linux, Solaris share the same FA in DMX?
Yes, if they share the same port flags
What are the Symmetrix External locks and how to check
and release?
Symmetrix external locks are used by SYMAPI (locks 0 to 15)
and also for applications assigned by EMC (>15) to lock access to the entire
Symmetrix arrayduring critical operations
We can check the external locks by giving the below command
symcfg -sid XXXX list -lockn
We can check the external locks by giving the below command
symcfg release -sid -lockn 15 -force
We can check the external locks by giving the below command
symcfg -sid XXXX list -lockn
We can check the external locks by giving the below command
symcfg release -sid -lockn 15 -force
How to monitor performance of EMC Symmetrix?
Using Performance Monitoring feature in EMC Control Center
Using SYMSTAT symcli command
Using SYMSTAT symcli command
How do you check the cache activity of front-end
directory?
symstat -sid 4282 -type cache -i 5 -c 4 -sa all
How do you check the I/O requests and throughput of
selected disk?
Symstat -sid 4282 -type disk -i 5 -c 3 -disk 2a,C,5
What are the available performance types in SYMSTAT
command?
REQUESTS: Reports I/O requests and throughput for selected
devices, directors, or SRDF/A sessions. (This is the default type; if no type
is specified REQUESTS is used.)
BACKEND: Reports back-end I/O requests and throughput for selected devices.
PORT: Reports performance statistics for a director port. ISCSI Report Gig-E network statistics.
CACHE: Reports cache activity for selected front-end or remote link directors, or SRDF/A sessions.
MEMIO: Reports cache memory to disk activity for selected devices. PATH Report R-Copy path information for nonincremental sessions. Symmetrix arrays that have all or some incremental sessions will report an error.
CYCLE: Report cycle summary information for SRDF-A sessions.
DISK: Reports back-end I/O requests and throughput for selected disks.
PREFETCH: Reports track prefetch disk activity for selected back-end directors only.DMSP Reports dynamic mirroring service policy (DMSP) statistics for the selected device(s).
RDF: Reports SRDF statistics from the perspective of RA groups, devices, or directors.
BACKEND: Reports back-end I/O requests and throughput for selected devices.
PORT: Reports performance statistics for a director port. ISCSI Report Gig-E network statistics.
CACHE: Reports cache activity for selected front-end or remote link directors, or SRDF/A sessions.
MEMIO: Reports cache memory to disk activity for selected devices. PATH Report R-Copy path information for nonincremental sessions. Symmetrix arrays that have all or some incremental sessions will report an error.
CYCLE: Report cycle summary information for SRDF-A sessions.
DISK: Reports back-end I/O requests and throughput for selected disks.
PREFETCH: Reports track prefetch disk activity for selected back-end directors only.DMSP Reports dynamic mirroring service policy (DMSP) statistics for the selected device(s).
RDF: Reports SRDF statistics from the perspective of RA groups, devices, or directors.
What is symmetrix optimizer and how it works?
Symmetrix Optimizer improves array performance by
continuously monitoring access patterns and migrating devices (Symmetrix
logical volumes) to achieve balance across the disks in the array
Step 1: Symmetrix Optimizer builds a database of device activity statistics on the Symmetrix back-end.
Step 2: Using the statistical data collected, configuration information, and the user-defined parameters, the Optimizer algorithm identifies busy and idle devicesand their locations on the physical drives. The algorithm tries to minimize average disk service time by balancing I/O activity across physical disks. Optimizer determines which disks require balancing by locating busy devices close to each other on the same disk, and/or by locating busy devices on faster disks or faster areas of the disks. Optimizer takes into account the speed of the disk, the disk geometry, and the actuator speed to determine faster disks.
Step 3: Once a solution for load balancing has been developed, the next phase is to carry out the Symmetrix device swaps. This is done using established TimeFinder technology, which maintains data protection and availability. we can specify whether swaps should occur in a completely automated fashion, or if the device swaps require user approval before the action is taken.
Step 4: Once a swap function completes, Symmetrix Optimizer continues data analysis for the next swap.
Step 1: Symmetrix Optimizer builds a database of device activity statistics on the Symmetrix back-end.
Step 2: Using the statistical data collected, configuration information, and the user-defined parameters, the Optimizer algorithm identifies busy and idle devicesand their locations on the physical drives. The algorithm tries to minimize average disk service time by balancing I/O activity across physical disks. Optimizer determines which disks require balancing by locating busy devices close to each other on the same disk, and/or by locating busy devices on faster disks or faster areas of the disks. Optimizer takes into account the speed of the disk, the disk geometry, and the actuator speed to determine faster disks.
Step 3: Once a solution for load balancing has been developed, the next phase is to carry out the Symmetrix device swaps. This is done using established TimeFinder technology, which maintains data protection and availability. we can specify whether swaps should occur in a completely automated fashion, or if the device swaps require user approval before the action is taken.
Step 4: Once a swap function completes, Symmetrix Optimizer continues data analysis for the next swap.
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