This discussion is now open. Please feel free to pose your questions to Saikat.

We look forward to hearing from you.

Regards,

Mark

This question was incorrectoy added asa seperate post by karenatoronto.

The original post is here and the tittle is the question:

one of our servers used to connect to cx-3, after we reinstall os, how can it still recongnize the data on san? thanks

I have reposted here for Saikat to address.

Regards,

Mark

This question came ino the Ask the expert Support Forum. Unfortunately it was posted as a seperate question. So I am reposting and linking it here for Saikat to answer.

From user mellacerna

From this thread: CX300 SPS A

"Hi,

It's really affecting the db performance once the SPS A in fault status?

we noticed that when SPS A was faulted, write cached was disable? does it affect the db performance?

or that cache is only if in case there is power failure?

thanks

mel"

Hi everybody,

Is a failed vault disk protected by hot spare disk? If not, how is the redundancy provided for the contents of vault disks?

Hey Astrit,

To add further RE hotsparing the vault drives: HSs are designed for user data redundancy. To keep with that design, the vault has multiple system partitions that are designed to be highly available without need for taking up HSs. I don't have a partition layout image on hand, but maybe Saikat could elaborate.

Cheers,
Matt

This question was posted as a seperate question but I have added it here to this conversation.

We are building High available cluster in Red Hat & EMC SAN It was posted by bdeviprasad

The question is

We are presenting 1 LUN of 10.7 GB on host machine through EMC Clarion storage.  But on host machine it is  showing 6 LUN.  Please guide us with basic step to integrate Host machine with EMC clarion storage(cx4960).

Hi Saikat

Unable to Download the documnet, getting below error

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Thanks Saikat,

Recently I got new requirement i.e. At present Our EMC SAN is located in Delhi and I want to represent ONE LUN from SAN to Different location Servers (Servers are located  nearly about 35 KM away from SAN ). is it feasible?  If yes  what kind of service/application/software I have to use for the same ? Pls advise me who to solve the problem without comprising the performance of the servers

we installed powerpath software in linux according to the documents, but when i give fdisk -l command it shows 3 LUNS, is it OK ? otherwise i have to use any different command to scan the luns, for more info see below logs, pls clarify me on the same

-------------------------------------------------------------------------------------------------------------------------

[root@osdd1 scsi]# fdisk -l

Disk /dev/sda: 1195.9 GB, 1195997396992 bytes

255 heads, 63 sectors/track, 145405 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          13      104391   83  Linux

/dev/sda2              14      145405  1167861240   8e  Linux LVM

Disk /dev/sdb: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1       10240    10485744    5  Extended

Disk /dev/sdc: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1       10240    10485744    5  Extended

Disk /dev/emcpowera: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

     Device Boot      Start         End      Blocks   Id  System

/dev/emcpowera1               1       10240    10485744    5  Extended

Please see the "EMC Host Connectivity Guide for Windows" on PowerLink at:

Home > Support > Technical Documentation and Advisories > Host Connectivity/HBAs > Installation/Configuration

http://powerlink.emc.com/km/live1/en_US/Offering_Technical/Technical_Documentation/300-000-603.pdf

The likely problem is the connections from the host to the array and not using PowerPath on the host. Each path from the host to the array will show up on the host as a different LUN. You need software on the host that knows how to take all the connections to the LUN and combine it into one object that Disk Manager sees as a single LUN.

glen

Dear Kelley,

Thanks for your response, but we have provide only one lun(10GB) both the host servers(Linux 5.6, Kernel 2.6)   than after we install EMC power path on the both the servers, When i check  fdsik -l command it giving following output

[root@osdd1 scsi]# fdisk -l

Disk /dev/sda: 1195.9 GB, 1195997396992 bytes

255 heads, 63 sectors/track, 145405 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          13      104391   83  Linux

/dev/sda2              14      145405  1167861240   8e  Linux LVM

Disk /dev/sdb: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1       10240    10485744    5  Extended

Disk /dev/sdc: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1       10240    10485744    5  Extended

Disk /dev/emcpowera: 10.7 GB, 10737418240 bytes

64 heads, 32 sectors/track, 10240 cylinders

Units = cylinders of 2048 * 512 = 1048576 bytes

     Device Boot      Start         End      Blocks   Id  System

/dev/emcpowera1               1       10240    10485744    5  Extended

Below is our Host to SAN Configuartion

We have server(IBM X3650M3) with Single HBA(Emulex) card having 2 ports, Two Switches(cisco MDS 9124) and EMC Clariion cx4-960 (in this we are using SP-A and SP-B deafult Ports ).

When we installed EMC Power Path why it showing multipathing? I need clarifcation on the same from ur side saying that is it ok to show the information like /dev/sdb and /dev/sdc. in my view it should show only one path i.e.  /dev/emcpowera1 why it showing /dev/sdb and /dev/sdc paths

for more information on powerpath

[root@osdd2 ~]# powermt display dev=all

Pseudo name=emcpowera

CLARiiON ID=CKM00103100642 [OSDD]

Logical device ID=60060160FB0E26003E98DA345C67E111 [LUN 6]

state=alive; policy=BasicFailover; priority=0; queued-IOs=0;

Owner: default=SP B, current=SP B       Array failover mode: 4

==============================================================================

--------------- Host ---------------   - Stor -   -- I/O Path --  -- Stats ---

###  HW Path               I/O Paths    Interf.   Mode    State   Q-IOs Errors

==============================================================================

   7 lpfc                     sdb       SP B0     unlic   alive       0      0

   8 lpfc                     sdc       SP A0     active  alive       0      0

Waiting for your response

Hi Saikat,

Is it ok if i use iscsi initator on the both side ?  We will make SAN iscsi port as an IP based Port,

Regards

Devi Prasasd

This Ask the expert event is now concluded. It will be closed for the present and will then be moved to the Clariion Support Forum/ Thanks to all for their participation during this event. And many thanks to our expert Saikat for taking the questions.

Regards,

Mark

This discussion has now been moved to Clarrion Support Forum and is now open for further discussion by the entire Clariion Support Community. Thanks again to Saikat for hosting this. He is no longer the host, but he may drop in and reply as and when he is available. A summary document of this discussion will be available in the coming days and will be linked to this discussion.

Thanks again for the participation.

Regards,

Mark