What is the maximum hyper size in DMX-4?
Maximum Cylinders = 65520
Maximum Capacity = 59GB or 61425 MB
Maximum Capacity = 59GB or 61425 MB
How many hypers can create in a Single disk in DMX4?
255 hypers per disk.
How many members can contain in one Meta?
1 Meta head + 255 members
How many LUN IDs available per FA port?
256 LUN IDs are available per FA port, 255 LUN IDs are usable
out of 256.
What is Dynamic LUN addressing?
This feature will automatically selects and assigns the LUN
IDs to the devices while device mapping to the port Instead of manually
assigning address to the device while mapping
How do you add a new member to the existing Meta?
add dev XXXX to meta XXXX, protect_data=TRUE,
bcv_meta_head=XXXX;
or for multiple ranges:
add dev XXX1:XXX6 to meta XXXX, protect_data=TRUE, bcv_meta_head=XXXX;
or for multiple ranges:
add dev XXX1:XXX6 to meta XXXX, protect_data=TRUE, bcv_meta_head=XXXX;
What is stripping and what is Concatenating?
Stripped Meta Devices:
Meta device addressing by striping divides each Meta member device into a series of stripes, addressing a stripe from each device before advancing to the next stripe on the first device. When writing to a striped volume, equal size stripes of data from each participating drive are written alternately to each member of the set.
Concatenated Meta Devices:
Concatenated devices are volume sets that are organized with the first byte of data at the beginning of the first device. Addressing continues to the end of the first device before any data on the next device is referenced. When writing to a concatenated device, the first meta device member receives all the data until it is full, and then data is directed to the next member and so on
Meta device addressing by striping divides each Meta member device into a series of stripes, addressing a stripe from each device before advancing to the next stripe on the first device. When writing to a striped volume, equal size stripes of data from each participating drive are written alternately to each member of the set.
Concatenated Meta Devices:
Concatenated devices are volume sets that are organized with the first byte of data at the beginning of the first device. Addressing continues to the end of the first device before any data on the next device is referenced. When writing to a concatenated device, the first meta device member receives all the data until it is full, and then data is directed to the next member and so on
What are the DMX-4 supported disk types, no. of disks and
maximum capacity?
FC drives, iSCSI drives and Flash drives
15 drives per DAE
120 drivers per Cage
240 drives per Storage Bay
2400 drives per array If total of 10 storage bays connected
Maximum storage capacity is 1 PB.
15 drives per DAE
120 drivers per Cage
240 drives per Storage Bay
2400 drives per array If total of 10 storage bays connected
Maximum storage capacity is 1 PB.
Briefly explain the DMX-4 supported Device types?
Standard Devices: A Symmetrix device configured for normal
Symmetrix operation under a desired protection method (such as RAID-1,RAID-S,
and SRDF®).
Gatekeeper Devices: SCSI commands executed by SYMAPI are transferred to the Symmetrix array via a Symmetrix device that is designated as a Gatekeeper device. The gatekeeper allows you to retrieve configuration and status information from the Symmetrix array without interfering with normal device I/O operations.
Meta Devices: Allow individual devices to be concatenated to create larger devices.
BCV Devices: Specialized devices used to create a local copy of data contained in a standard Symmetrix device, which can be used for backup, restore, decision support, and application testing.
SRDF Devices (R1, R2 and R21) Devices configured as RDF1 or RDF2 to support SRDF operations.
R1 is source device for SRDF operations
R2 is target device for SRDF operations
R21 is used for multi hop SRDF operations
Virtual Devices: A host-accessible device containing track-level location information (pointers), which indicates where the copy session data is located in the physical storage. Device copies use virtual devices to support TimeFinder/Snap operations. Virtual devices consume minimal physical disk storage, as they store only the address pointers to the data stored on the source device or a pool of save devices.,
Save Devices: Special devices (not mapped to the host) that provide physical storage space for pre-update images or changed tracks during a virtual copy session of TimeFinder/Snap operations.
Device Masking (VCM)Devices: Symmetrix devices that have been masked for visibility to certain hosts. The device masking database (VCMDB) holds device masking records and typically resides on a 24 or 48 cylinder disk device..
DRV Devices: A non-user-addressable Symmetrix device used by the Symmetrix Optimizer to temporarily hold user data while reorganization of the devices is being executed. Typically, it is used by the Optimizer in logical volume swapping operations.
Gatekeeper Devices: SCSI commands executed by SYMAPI are transferred to the Symmetrix array via a Symmetrix device that is designated as a Gatekeeper device. The gatekeeper allows you to retrieve configuration and status information from the Symmetrix array without interfering with normal device I/O operations.
Meta Devices: Allow individual devices to be concatenated to create larger devices.
BCV Devices: Specialized devices used to create a local copy of data contained in a standard Symmetrix device, which can be used for backup, restore, decision support, and application testing.
SRDF Devices (R1, R2 and R21) Devices configured as RDF1 or RDF2 to support SRDF operations.
R1 is source device for SRDF operations
R2 is target device for SRDF operations
R21 is used for multi hop SRDF operations
Virtual Devices: A host-accessible device containing track-level location information (pointers), which indicates where the copy session data is located in the physical storage. Device copies use virtual devices to support TimeFinder/Snap operations. Virtual devices consume minimal physical disk storage, as they store only the address pointers to the data stored on the source device or a pool of save devices.,
Save Devices: Special devices (not mapped to the host) that provide physical storage space for pre-update images or changed tracks during a virtual copy session of TimeFinder/Snap operations.
Device Masking (VCM)Devices: Symmetrix devices that have been masked for visibility to certain hosts. The device masking database (VCMDB) holds device masking records and typically resides on a 24 or 48 cylinder disk device..
DRV Devices: A non-user-addressable Symmetrix device used by the Symmetrix Optimizer to temporarily hold user data while reorganization of the devices is being executed. Typically, it is used by the Optimizer in logical volume swapping operations.
What is Vault drives and Hot Spare?
Vault Drivers: At the time of emergency shutdown of an
Array, what ever the data in cache memory will be destaged/saved on temporary
drives called vault drives
Hot Spare: At the time of physical drive failure hot spare drives will take place
Hot Spare: At the time of physical drive failure hot spare drives will take place
What is Preview, Prepare and Commit while using
Symconfigure command?
The preview argument verifies the syntax and correctness of
each individual change defined, and then terminates the session without change
execution.
The prepare argument performs the preview checks and also verifies the appropriateness of the resulting configuration definition against the current state of the Symmetrix array; the argument then terminates the session without change execution
The commit argument completes all stages and executes the changes in the specified Symmetrix array
The prepare argument performs the preview checks and also verifies the appropriateness of the resulting configuration definition against the current state of the Symmetrix array; the argument then terminates the session without change execution
The commit argument completes all stages and executes the changes in the specified Symmetrix array
What are the possible device service states and device
status states?
Device Service States : Normal, Failed and Degraded
Device Status States : Ready, Not Ready and Write Disable.
Device Status States : Ready, Not Ready and Write Disable.
How do you reserve the devices?
symconfigure -sid XXXX -f createdev.cmd -expire expiration
date-owner myself -comment "this devices are reserved for SRDF activity"
reserve
How do you create the Disk Groups
We can not create Disk Groups, It should be done by changing
BIN file by CE.
We can rename the existing disk groups.
Example: symconfigure -sid 207 -cmd “set disk_group 4 disk_group_name = flash_dsks;” -v -nop commit
We can rename the existing disk groups.
Example: symconfigure -sid 207 -cmd “set disk_group 4 disk_group_name = flash_dsks;” -v -nop commit
How do you check the free space by Disk group and Array
as whole?
By Disk Group : Symdisk -sid XXXX list -by_diskgroup
Array as whole : Symconfigure -sid XXXX list -freespace
Array as whole : Symconfigure -sid XXXX list -freespace
How do you check the total assigned devices to a
particular Host?
Symmaskdb -sid XXXX list devs -wwn "host hba wwn"
How do you check the total allocated storage of a
particular Host?
symmaskdb -sid XXXX list capacity -Host hostname
What is pre check list to assign storage to the host?
Verify the available free space in the symmetrix array
symconfigure -sid SymmID [-v | -freespace [-units cylinders | MB]] list
symdisk -sid "SymID" list -disk_group "GroupNumber"
Verify the Symmetrix status
Symconfigure -sid "SymID" verify
If any hung activities found abort
symconfigure -sid "SymID" abort
symconfigure -sid SymmID [-v | -freespace [-units cylinders | MB]] list
symdisk -sid "SymID" list -disk_group "GroupNumber"
Verify the Symmetrix status
Symconfigure -sid "SymID" verify
If any hung activities found abort
symconfigure -sid "SymID" abort
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