Storage Software
1748209 Members
2779 Online
108759 Solutions
New Discussion юеВ

SSUS scripting & EVA disk location.

 
SOLVED
Go to solution
Steve Lawrence_1
Occasional Advisor

SSUS scripting & EVA disk location.

Hi all,

When using a SAN Management Appliance (OS 2.1) I can locate a disk in a disk group, click on it and it'll show me at the bottom of the disk's page which enclosure & bay the disk is located in.

I'd like to be able to do this programatically via SSUS.

Now, I can query my EVA and ask for a disk's information :

EVA> show disk "\Disk Groups\146 GB Disk Group\Disk 059"

\Disk Groups\146 GB Disk Group\Disk 059 information:
Identification:
Name : \Disk Groups\146 GB Disk Group\Disk 059
Loop_Pair : LoopPair1
Node_World_Wide_ID : 2000-000C-50A8-9E1D
rssid :
rssindex :
Loop A:
Port_World_Wide_ID : 2000-000C-50A8-9E1D
Assigned_Lun : 0
Loop_ID : 86
loopalpa : 4d
Loop B:
Port_World_Wide_ID : 2000-000C-50A8-9E1D
Assigned_Lun : 0
Loop_ID : 86
loopalpa : 4d
Condition State:
Operational_State : Normal
Migration_State : Not migrating
Failure_Prediction : No
Media_Accessible : Yes
Loop_A_State : Normal
Loop_B_State : Normal
Physical:
Type : Fibre Channel Disk
Manufacturer : HPQ
Model_Number : BD14655B2A
Firmware_Revision : HP03
Formatted_Capacity : 136.73 GB
System:
Requested_Usage : Member of StorageCell
Actual_Usage : Member of StorageCell
Disk_Group : \Disk Groups\146 GB Disk Group
Occupancy : 56.84 GB
Comments :
ID : 3a0807100c0000201d9ea8500000000000000000

However I'm not seeing here any information about it's actual location. I'm supposing I could divine this from its Loop Pair & LoopID.

I can also get information on the enclosure itself by doing a :

EVA> show monitor "\Hardware\Rack 1\Disk Enclosure 1"

And of the information that results I can see things like :

Sensor : DISK1TEMP
Status : NotInstalled
Tmp : F/ C
Alarms : N/A
Sensor : DISK2TEMP
Status : NotInstalled
Tmp : F/ C
Alarms : N/A
Sensor : DISK3TEMP
Status : OK
Tmp : 69.8 F/21.0 C
Alarms : None

Which allows me to figure out if there's a disk in a bay or not.

But I'm still unable to figure out how to determine which disk is in which enclosure/bay.

Is there something I'm missing? Can anyone help me determine how to correlate a disk's information so I can map my EVA?

Thanks in advance,
Steve Lawrence.
21 REPLIES 21
Uwe Zessin
Honored Contributor

Re: SSUS scripting & EVA disk location.

Steve,
there simply is not enough information presented through SSSU to get that information. I have checked this myself some time ago and I have asked several people from HP who have been helpful in the past, but unfortunately they could not come up with a solution.

You might try to use the AL_PA or Loop-ID, because the EVA is now using hard addressing, but that can be screwed up if a disk is being replaced and the algorithm is not published anyway.

I have renamed the disk drives as a workaround, e.g. "Disk E01 B12". I also feel that gives a better overview when I check the Disk Groups.


Yes, yes, I know we are not supposed to 'micro-manage' the EVA. I have been through this multiple times now...
.
Steve Lawrence_1
Occasional Advisor

Re: SSUS scripting & EVA disk location.

>there simply is not enough information presented through SSSU to get that information.

So, it's not just me...

>You might try to use the AL_PA or Loop-ID

What is loopalpa : 4d?
Loop-ID's I can cope with, but loopalpa is a new one on me.

>I have renamed the disk drives as a workaround, e.g. "Disk E01 B12". I also feel that gives a better overview when I check the Disk Groups.

That's fair enough. Unfortunately it's just cosmetic. My problem is that I have multiple presentations, and they need to get striped down the EVA.

If I lose a disk, and I have the 'auto-insert' turned on, then it'll grab a spare and slap it into my group. If that spare happens to be in the same enclosure as another disk in the same group I've lost my stripe.

What ends up happening is when a disk fails a spare is swapped in, the tech pulls out the dead disk, replaces dead disk, and then physically removes the spare - all in order to keep the stripes down the EVA correct.

What *I* would like to do is, instead of manually clicking all over the SAN GUI to check that the disks are all in nice, neat lines going down the enclosures, run an SSSU script to suck out each disk's position / grouping / LUN and present it as an easy to look at web page or something.

(I'm more than proficient at the perl side of hacking apart the SSSU output... I just can't find the right output to hack.)

It *has* to be able to be done, 'cos the GUI gets the information somehow.

I suppose I could run a 'Capture configuration' and see what that tells me what to do. Theoretically that should create me a configuration *exactly* the same as the one I have now, yes? Which I'm positing would be exact down to the location of each disk...

Steve.
Uwe Zessin
Honored Contributor

Re: SSUS scripting & EVA disk location.

Steve,

"loopalpa": AL_PA is for "Arbitrated Loop - Physical Address". It is how devices are addressed on an FC_AL (Fire Channel - Arbitrated Loop'). It is _somewhat_ similar to an IP address. The MAC address' equivalent is the WWN of the Fibre Channel port.

AL_PA and Loop-ID mean the same thing. AL_PAs start from 0 (reserved for the FL_Port) and then go: 1, 2, 4, 8, 15, ... (there are many holes in it due to the way FC_AL works). A low values implies a high priority on the loop. The Loop-ID is from 0..127, but a low value implies a low priority.

Loop-ID is just a user-friendly way to hide the rather crude AL_PA values.

-

Sorry, but I am afraid you misunderstand the EVA: it simply does not have a dedicated spare disk. If you set a disk group's "protection level" to 1 or 2 it reserves "spare capacity" and distributes it equally over all disks in the disk group (distributed sparing). If a disk fails, all its VRAID-1 and VRAID-5 data is recovered and written to the "spare capacity" on the other disks (it is not exactly true if there is free space in the disk group, but let's leave it simple).

When the defective disk is replaced and a new disk is added to the disk group (be it through "auto-insert" or a manual "group") the EVA will use its standard load leveling feature. There is no knowledge kept that a particular bay position was once a member of a particular disk group.

The good thing is that all disks in the group are available for I/Os. The negative thing is that each disk group has its own "spare capacity", but such is life: even breakfast is not free.

I have not played with "auto-insert", but my understanding is this:
if it is turned on, it will put _any_ new disk into _the_ disk group which has the least amount of free space!

I really suggest you do a "CAPTURE CONFIGURATION" - that should always be done after any change to the EVA, because it is THE ONLY WAY to recover the configuration. Well, if you then check the file you will see that it has nothing in it that refers to physical disk positions!
.
Steve Lawrence_1
Occasional Advisor

Re: SSUS scripting & EVA disk location.

Ahh...

You are of course, quite correct. And I am confusing myself with my HSG disks which do have spares, and suffer from the above.

Those I'd also like to map, but that's an entirely different story.

I shall soldier on and see what I can come up with. Thanks for the info.

Steve.
Uwe Zessin
Honored Contributor

Re: SSUS scripting & EVA disk location.

Well, good luck or have fun - whatever you prefer ;-)

The output from the HSG can look quite entertaining sometimes, beleive me. I have written a map/reporting utility, but I can not give it away, sorry.
.
Steve Lawrence_1
Occasional Advisor

Re: SSUS scripting & EVA disk location.

Really...

I have to admit I've not even begun on *that* path.

Am I right in thinking that SSSU doesn't do HSG reporting. And if so, could you clue me in on what you *do* use to get config details on an HSG?

Steve.
Uwe Zessin
Honored Contributor

Re: SSUS scripting & EVA disk location.

Hello Steve,
you are correct. SSSU can not do HSG reporting. It looks to me like it is using some XML-based protocol to talk via TCP/IP to the SMA which then talks via Fibre Channel to the EVA.

I usually connect a notebook via serial port to the HSG's maintanance port and capture the output of the CLI "SHOW" commands. In our own facility we have put the HSG's ports onto a terminal server. We then use a terminal emulator on a PC to connect via TELNET protocol to different TCP ports on the terminal server which are mapped to its physical ports. We have also put all other devices with serial ports (except for the EVA ;-) on the server. That allows us console access from any room.

It is also possible to have a host-based program that talks via the SWCC agent or directly in-band over Fibre Channel to the HSG. These days it is called the "HP StorageWorks Command Scripter", but it is an extra-cost option:
http://h18000.www1.hp.com/products/sanworks/commandscripter/index.html
.
Mike Naime
Honored Contributor

Re: SSUS scripting & EVA disk location.

Steve:

Have you tried the LOCATE command with a UNIT name on the HSG's? I.E. LOCATE D1 will show all of the drives associated with unit D1.

We also use the CLI port plugged into a Decserver 700's to manage our HSG's. This is monitored/accessed by TDI's ConsoleWorks. Add VPN and a Wireless card to your Laptop... And you are managing from anywhere that you can get Internet Access. :-)

On the EVA. I think that you are trying to micro manage it too much. Let the EVA do it's thing! Your sparing level is the number of disks that you can easily sustain drive failures of without loosing your data. Select disks after this (Depending on RSS groups) can also be lost without data loss occuring.

Manage the space. not the spindles!
VMS SAN mechanic
Erwin van Londen
Valued Contributor

Re: SSUS scripting & EVA disk location.

Steve,

Be aware though that the only this you can do regarding redundancy is the location of the drives with regards of the RSS configuration. If you have more than 1 drive in the same shelf which belongs to the same RSS (redundant storage set) and that shelf failes you will lose you vraid5 sets.
The only thing you can do about that is keep track of the location of the drives and place each drives of an RSS in another shelf. (This implies you need a minimum of 8 shelfs)

Regards,
Erwin van Londen
HP Master ASE SAN Architect.
https://erwinvanlonden.net