Tuesday 28 February 2012

HBA - HOST BUS ADAPTER

HBA= HOST BUS ADAPTER  
           
HBA is the device which is inserted in the server and storage  mother board PCI slot.
Fibre channel(FC) cable connected in HBA ports.
HBA that interconnects with servers, switches and storage devices on the fabric switch.
FC HBA have (world wide port number WWPN and WWNN (world wide node name) like MAC address


     

Open Systems SnapVault


Extend and enhance your data protection strategy.

Designed to safeguard open storage platforms faster and more cost effectively, Open Systems SnapVault® (OSSV) is your key to simplifying and extending NetApp® data protection strategies.

Open Systems SnapVault leverages the block-level incremental backup technology found in SnapVault to protect Windows®, Linux®, UNIX®, SQL Server®, and VMware® systems running on mixed storage.OSSV increases performance and enables more frequent data protection by moving and creating backups from changed data blocks, not entire changed files. And since only changed blocks are stored, less capacity is needed.

OSSV is particularly well suited for centralizing D2D backups from remote offices.

NetApp OSSV recently introduced support for Microsoft® SQL Server database backups. We also made OSSV available as a free download from our customer support site (formerly NOW®), to maximize the cost savings and backup efficiencies generated by your NetApp SnapVault systems.

For more information on the benefits of OSSV for efficient D2D backup of non-NetApp data, please read theOpen Systems SnapVault datasheet. For more information on how our core Snapshot® and replication technologies can protect NetApp data, please visit the SnapVault page. And to see how NetApp Syncsort Integrated Backup extends OSSV capabilities to more applications and recovery scenarios, please visit the NSBpage.




Please write your valuable comments, about my blogspot.

Wednesday 22 February 2012

Netapp HR Question


1. Tell me about yourself? Your work? Your designation & your responsibilities? 
I am name from place, I have 3+ years experience in IT, I had completed (dgree name in college name ). I debuted to (your first company name) as system administrator from (month and year) to (month and year). And I got offer in (Second company name) as a storage admin from (month and year) to still now. And my current job profile is(say some important points) 
 2. Why did you leave your last job?
                      Or 
Why are you looking for a job change?

Speak positive think and never say major problem with management Team leader and co-workers with current organization.
Better say knowledge and career growth.
I don't have access for filler.

3. In what areas you would like to improve yourself?

Try to include improvement activities that relate to the job. A wide variety of activities can be mentioned as positive self-improvement. Have some good ones handy to mention

4. What do you know about this organization?

Please refer the respective company website, shares, top management before going to interview.

5. Do feel yourself successful roll in current job?

Please say yes and speak about the critical work you faced in your current job.

6. What experience do you have in this field?

Now you can speak about the position you applying for, if there is no reason to say means try close as you can , please don’t try to overcome.

7. What are your expectations in salary?

Can you tell me the range for this position? In most cases, the interviewer, taken off guard, will tell you. If not, say that it can depend on the details of the job.

8. Explain how you would be an asset to this organization?

It gives you a chance to highlight your best points as they relate to the position being discussed. Give a little advance thought to this relationship.

9. Why should we hire you?

Please do not compare with any other candidates in old company and new company to make impress interviewer


Please write your valuable comments, about my blogspot.

NetApp Interview Question

NetApp Interview Question 


How to improve the Netapp storage performance?

  1. There is no direct answer for this question but we shall do it in several way. 
  2. If volume/lun present in ATA/SATA harddisk aggregate, then the volume can be migrated to FC/SAS disk aggregate. 
  3. For NFS/CIFS instead of accessing from single interface, multi mode vif can be configured to get better bandwidth and fault tolerance. 
  4. Always advised to keep aggr/vol utilization below 90%. 
  5. Avoid doing multiple volume backup in single point of time. 
  6. Aggr/volume/lun reallocation can be done to re–distribute the data to multiple disk for better striping performance. 
  7. Schedule scrubbing and deduplication scanning after business hours. 
  8. Avoid connecting different types of shelf in a same loop. 
  9. Avoid mixing up different speeds of disk and different types of disk in a same aggregate. 
  10. Always keep sufficient spare disk to replace incase of disk failure. Because reconstruction time will take more time and cause negative performance. 
  11. Keep the advised version of firmware/software which is recommended by netapp. 
  12. Better to have nearstore functionality to avoid backing up data from source filer. 

Unable to map lun to solaris server, but solaris server side no issue. How to resolve the issue?

FROM STORAGE SIDE:
  1. Verify iscsi/fcp license is added in storage 
  2. Verify iscsi/fcp session is logged in from server side 
  3. Verify luns are mapped to the corresponding igroup. 
  4. Verify whether correct host type is mentioned while creating igroup and lun 
  5. Verify whether correct iqn/wwpn number is added to igroup 
  6. Verify zoning is properly configured from switch side. 
How to create the LUN for solaris server?
  1. lun create –s size –t solaris /vol/vol1/lunname 

How to create qtree and provide the security?

Qtree create /vol/vol1/qtreename
Qtree security /vol/vol1/qtree unix|ntfs|mixed

How to copy filer to filer?

ndmpcopy or snapmirror

How to resize the aggregate?

Aggr add agg(name) no.of.disk

How to increase the volume?

Traditional

Vol add vol(name) no.of.disk

Flexiable

Vol size vol(name) +60g

What is qtree?

Qtree are Logical partition of the volume

What is the default snap reserve in aggregate?

5%

What is snapshot?

Copy(read only) of active file system

What are the raid groups netapp supporting?, what is the difference between them?

Raid_dp(double parity,diagonal parity) ,raid4(striping&dedicated parity)

What are the protocols you are using?

Say some protocols like NFS, CIFS, ISCSI and FC
What is the difference between iscsi and fcp?

Iscsi-sending block through(tcp,ip)

Fcp-send through fibre medium
What is the iscsi port number your are using?

860 and 3260

What is the difference between ndmp copy and vol copy?

Ndmp copy –network data management protocol(used for tape backup)

Vol copy – is used to transfer volume to same or another aggr 


What is the difference between ONTAP 7 & 8?

In ONTAP 7 the individual aggregate is limited to maximum of 16 TB. Where ONTAP 8 supports the new 64 bit aggregate and hence the size of the individual aggregate extends to 100 TB.

What are the steps need to perform to configure SnapMirror?

The SnapMirror configuration process consists of the following four steps:

a. Install the SnapMirror license on the source and destination systems: license add <code>

b. On the source, specify the host name or IP address of the SnapMirror destination systems you wish to authorize to replicate this source system.

options snapmirror.access host=dst_hostname1,dst_hostname2

c. For each source volume or qtree to replicate, perform an initial baseline transfer. For volume SnapMirror,

restrict the destination volume first: vol restrict dst_vol

Then initialize the volume SnapMirror baseline, using the following syntax on the destination:

snapmirror initialize -S src_hostname:src_v

oldst_hostname:dst_vol

For a qtree SnapMirror baseline transfer, use the following syntax on the destination:

snapmirror initialize –S src_hostname:/vol/src_vol/src_qtree

dst_hostname:/vol/dst_vol/dst_qtree

d. After the initial transfer completes, set the SnapMirror mode of replication by creating the

/etc/snapmirror.conf file in the destination’s root volume.

For reference:


While doing baseline transfer you’re getting error message. What are the troubleshooting steps you’ll do?


Check both the hosts are reachable by running “ping” command
Check whether the TCP port 10566 & 10000 are open
Check whether the snapmirror license are installed in both and destination

Explain the different types of replication modes.

The SnapMirror Async mode replicates Snapshot copies from a source volume or qtree to a destination

volume or qtree. Incremental updates are based on a schedule or are performed manually using the

snapmirror update command. Async mode works with both volume SnapMirror and qtree SnapMirror.

SnapMirror Sync mode replicates writes from a source volume to a destination volume at the same time it is

written to the source volume. SnapMirror Sync is used in environments that have zero tolerance for data loss.

SnapMirror Semi-Sync provides a middle-ground solution that keeps the source and destination systems more

closely synchronized than Async mode, but with less impact on performance.

How do you configure multiple path in Snapmirror?

Add a connection name line in the snapmirror.conf file
/etc/snapmirror.conf
FAS1_conf = multi (FAS1-e0a,FAS2-e0a) (FAS1-e0b,FAS2-e0b)

Explain how De-Duplication works?

In the context of disk storage, deduplication refers to any algorithm that searches for duplicate data objects (for example, blocks, chunks, files) and discards those duplicates. When duplicate data is detected, it is not retained, but instead a “data pointer” is modified so that the storage system references an exact copy of the data object already stored on disk. This deduplication feature works well with datasets that have lots of duplicated date (for example, full backups). 


What is the command used to see amount of space saved using deduplication?

df –s <volume name>

Command used to check progress and status of deduplication?

sis status
How do you setup Snapvault Snapshot schedule?

pri> snapvault snap sched vol1 sv_hourly 22@0-22

This schedule is for the home directories volume vol1
Creates hourly Snapshot copies, except 11:00 p.m.
Keeps nearly a full day of hourly copies

What is metadata? 

Metadata is defined as data providing information about one or more aspects of the data,

1. Inode file
2. Used block bitmap file
3. Free block bitmap file
How do you shutdown filer through RLM?

telnet “rlm ip address”
RLM_Netapp> system power on

After creating LUN (iSCSI) & mapped the lun to particular igroup, the client not able to access the LUN. What are the trouble shooting steps you take?

Check whether IQN number specified is correct
Check whether the created LUN is in “restrict” mode
Check the iscsi status

In CIFS how do you check who is using most?

Cifs top

How to check cifs performance statistics

cifs stat

What do you do if a customer reports a particular CIFS share is responding slow?

Check the r/w using "cifs stat" & "sysstat -x 1".
If disk & cpu utilization is more then problem is with filer side only.
CPU utilization will be high if more disk r/w time, i.e.,during tapeback up & also during scrub activities.

what is the degraded mode? You have parity for failed disks then why the filer goes to degraded mode?

If the spare disk is not added within 24hours,then filer will be shutdown auomatically to avoid further disk failures and data loss.

Did you ever do ontap upgrade? From which version to which version and for what reason?

Yes i have done ontap upgrade from version 7.2.6.1 to 7.3.3 due to lot of bugs in old version.

How do you create a lun ?

lun create -s <lunsize> -t <host type> <lunpath>

Production Manager?

Production manager will do the planning,co-ordinating and controlling the process.

Performance Manager?

Performance manager will analyses the performance trends of application.systems and services.

How do you monitor the filers?

Using DFM(Data Fabric Manager) or also using SNMP you can monitor the filer.

What are the prerequisites for a cluster?

cluster interconnect cable should be connected.

shelf connect should be properly done for both the controllers

cluster license should be enabled on both the nodes

Interfaces should be properly configured for fail over

cluster should be enabled

What are the scenarios you have for a cluster failover?

If disk shelf power or shelf port is down, then failover will not happen. It cannot access the mail box disk. Mail box disk stores the cluster configuration data.

What is the diff bet cf takeover and cf force takeover?

If partner shelf power is off (metrco cluster), the forcetakover will work else normal takeover will work.


Please write your valuable comments, about my blogspot.