HP EVA 5000 & Linux

[Sandeep Sanjao Figer]

Hi,
I am new to Linux & HP SAN. I have just installed Red hat Enterprise AS 3 on HP DL360 with two FC HBA cards. The server seems to communicating to SAN properly. On the SAN now, I am trying to make VDisk & present it to my Red Hat server. How do I see that disk from my Linux box once presented. I would like to than mount it for my use.

Also, anyone ware if Veritas 10 agent has any issues on Rad Hat.

Regards,
Sandeep

[SAKET_5]

Hi Sandeep,

A few quick pointers:
1. So you have created a host for your Linux box under Command View EVA by adding both of its FCA ports?. For the host OS setting for Linux, select "Sun Solaris", as you wont see a value for Linux.
2. You then create a Vdisk and present it to the Linux host that you created in step1.
3. Now you log on to the host and assuming you are using Qlogic FCAs, you can then use HP's "FibreChannelUtilities RPM" which contains a number of utilities such as "adapter_info", "hp_rescan", "hp_system_info", "lssd", "probe_luns" and "scsi_info". A README file ofcourse explains all these utilties and they work fairly well in my experience with scanning new disk devices etc online on Linux. If you have not installed this RPM, you can download it from the following link.
Check this out:
http://h18000.www1.hp.com/support/files/server/us/download/21485.html

Once you have scanned the new disks, you should see 4 instances of the same disk (assuming your SAN consists of dual redundant fabrics).

[SAKET_5]

Sandeep,

Are you intending to use Secure Path software for linux for multi pathing and failover? If you use this software, you should only see one instance of the disk.

Use your normal, "format" procedures under Linux to then proceed on with filesystem setup.

If for whatever reason, you intend not to purchase Secure Path, you could install Qlogic failover driver - this provides multipathing and failover.

Let me know if you need any more info.

If the response was of any benefit to you, please show your appreciation by assigning points to them.

Regards,
Saket.

[Sandeep Sanjao Figer]

Hello Saket,

I have Qlogic FCA's & Secure path is already installed. Infact one of my colleague had already assigned two vdisks to existing Linux install as I see Red Hat Linux option under hosts on EVA. That LVM seems to be working fine. I can see the entry through fstab & df command also. I am trying to make two more vdisks & present to SAN for some addition partitions. As I see, LVM is been created for the two disks earlier assigned & one single mount is created. I would like to to have similar volume, perhapes two different partitions in it. Before I could receive your email, i had run probe_luns command which locked the server & now even after reboot I can not use my normal VNC either, which is not an issue now & can be fixed later. I wanted to know how I could see these new vdisks made on EVA in My Linux server so as to have a volume & use it for my needs. On Windows it was simpler to use Veritas Volume manager or disk admin program. Your help is greatly appreciated.

Regards,
Sandeep

[Bob_Vance]

'probe-luns' does not rescan the bus; it just re-registers device names for currently-recognized LUNs.

You need to make the driver re-scan the bus.
HP provides '/opt/hp/hp_fibreutils/hp_rescan' that will re-scan the bus, but it also calls 'probe-luns'.
'probe-luns' de-registers all current devices and re-creates them -- I'm a little nervous about that -- and, in fact, you say that it hung your system :{

I prefer to do it on an ad-hoc basis.
Each driver has his own way (see stuff at end of this post).

Having said that, however, you did a reboot which would fix all this. I suspect that your presentation of the LUNs from the EVA is not correct or not complete. Or, are you *sure* that the new LUNs are not being seen?
Are you just trying to see them from SecurePath and have not configured them yet?


hth
bv


Manual rescan for Qlogic:

Create new lun
Get Qlogic instance
... ## find /proc/scsi/ql* -name '[0-9]'
........ /proc/scsi/qla2300/2
List current LUNs
... ## cat /proc/scsi/qla2300/2
........ <>

Test next available device name (should fail)
... ## dd if=/dev/sdX of=/tmp/l1 count=100
........ dd: opening `/dev/sdX': No such device or address

Now, here's the first trick:
Force a Qlogic rescan of that instance
(the string that you echo varies from driver to driver and this only works for Qlogic):
... ## echo scsi-qlascan > /proc/scsi/qla2300/2

List the current LUNs
... ## cat /proc/scsi/qla2300/2
........ <>

This is the second trick.
Register the new device name with OS (this is what 'probe-luns' does)
... ## echo scsi add-single-device INST 0 TARGET LUN > /proc/scsi/scsi
........ (where
........ INST= instance number, not full /proc name
........ 0 is the bus# -- generally 0
........ TARGET is from the LUN list
........ LUN is the new LUN number
........ )
List the current LUNs
... ## cat /proc/scsi/qla2300/2
........ <>

Now test new device name (should work)
... ## dd if=/dev/sdX of=/tmp/l1 count=100
........ 100+0 records in
........ 100+0 records out


Continue with partition creation.

[Sandeep Sanjao Figer]

Hi.

The vdisk are configured okay on the SAN but perhapes being new to Linux I am not sure how to see first time under Linux before I actually start partition or try make a LVM.. As per the attached fstab, the /Data is vdisk from SAN & I can see it mounted from /dev/DATA_VG/DISK_LV2. Also under QLA2300 folder I see three files 0 1 & HBbaApiNode. Is there anyway (command??)I can see the disk presented to Linux hosts before I proceed for partition? What I have done till now is just make VDISKS on EVA & presented to hosts & need to work from Linux side to make them usable.

Regards,
Sandeep

[Bob_Vance]

From my previous reply,

## echo scsi-qlascan > /proc/scsi/qla2300/0
## echo scsi-qlascan > /proc/scsi/qla2300/1

should make the new LUNs show up with an "*" in a:

## cat /proc/scsi/qla2300/0
## cat /proc/scsi/qla2300/1

Then assign them to a device via:

## echo scsi add-single-device INST 0 TARGET LUN > /proc/scsi/scsi

e.g., assuming that adapter 1 now shows a (target 0,LUN 1), something like:
... ( 0: 1): Total reqs 1, Pending reqs 0, flags 0x0*, 1:0:81,
then execute:

## echo scsi add-single-device 1 0 0 1 > /proc/scsi/scsi

This would be instance 1 (/proc/scsi/qla2300/1), Channel 0 on Adapter, Target ID 0, LUN 1

## cat /proc/scsi/qla2300/1
should now show (Target 0, LUN 1) without the asterisk.


But, a reboot does all that and you've done a reboot.


bv

[Sandeep Sanjao Figer]

hi..
comands given give me permission denied even though Iam using root account & rwx permissions on the folder..Trying to figure out whats holding permissions

[Brent McConnell]

I have uploaded a document that should answer all your questions.

Brent

[Sandeep Sanjao Figer]

The document was very useful to understand. lssd gives me output as attached. My questions are very basic. I have for VDISKS done on EVA & my colleague had done LVM with first two disks. I am trying to see two new vdisks added by me on Linux box through commands. As from lssd file, how do i veify new disks added & than create partition / volume to make usable.

Regards,
Sandeep

[Brent McConnell]

If I understand your question correctly, you can use /opt/hp/hp_fibreutils/scsi_info for each of the devices output in lssd. This will give you an output that includes the world wide LUN id. You can match this to the world wide LUN id from command view eva. This will tell you which device in Linux matches which Vdisk on the EVA. Does that answer your question?

[Sandeep Sanjao Figer]

As per my earlier emails, I am stuck at the basics. My colleague has alreay allocated two vdisks as LVM to Linux server. I have also made 2 new vdisks & presented two linux hosts. s per my last email, I see four entries likde sda,sdb,sdc etc but not sure what to do next to have those new disks make workable under linux. I need to make a volume with those disks & mount with proper name later. Also, the current LVM mounted (DISK_VG) has name wrongly typed & if i unmount & change proper entruy in fstab & mount again renaming it, it given than error while booting.

Regards,
Sandeep

[Brent McConnell]

Okay, how about this. If you are comfortable with the devices listed in lssd. You would partition the devices however you like, then run pvcreate on the partitions you wish to use with LVM. After that you create your volume groups and logical volumes.

I've attached a paper that details LVM usage.

[Sandeep Sanjao Figer]

Hi,

Will try as per the document tommorrow. Hope it will not disturb existing vdisks presented to linux. lssd shows 4 entries but does not show representation based on size or any other identification

regards

sandeep