Understanding Disk Management and Lun Identification Issues: What Can HP-UX Do Better?

[SAM TEAM]

Hello! What can HP-UX do better to make managing disks and arrays easier? Managing storage (with complex/large configs) is sometimes an elaborate process (keeping track of which lun is which and what it is actually used for). We want to understand the issues involved with this and what could be done to improve upon the current offering at the OS level to make your life easier. :)

Much of the issue stems from the way disks/storage is represented at the OS level and how that differs from how the storage system itself represents or configures it. This, however, is not only a SAM concern but something to apply to many HP-UX utilities (CLIs, Ignite-UX, etc.), so please do not only apply it in the context of SAM. Any feedback to the following questions will be helpful in addressing the current issues and providing a better solution.

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1. First to understand your environment:
a. How many disks do you manage?
b. Approx. largest number of disks connected to a system?
c. Do you use direct attached storage, SANs, or both?

2. Understanding disk (lun) device issues:
a. What are the issues you have in understanding you have the correct device (e.g. when selecting a disk for configuration or tracking down a problem)?

b. What are the issues you have mapping a device on the OS to the component within the storage system.

3. Your input for making it better:
a. What type of information (e.g. lun number/name) would you need to see to help correctly identify your disk devices? And secondly, where in specific (e.g. CLI, application, etc.) would you want to see this data?

b. Any thoughts on a solution/feature (within OS or storage system) that could be provided to make this all easier in your environment?

4. Does your organization track disk configuration with a spreadsheet or web page (or other format: script, etc.) to represent the data in a specific view/format? If you are willing (or even allowed :) to send us a copy, please email: sam-invest@hpuxweb.hp.com. We are interested in looking at how you track this information and will analyze this for future enhancement, AND, not share it with anyone.

5. Any additional comments?

[Steven E. Protter · Accepted solution]

One little thing that has always bothered me a bit concerning SAM/LVM and lvm in general is finding device names.

When i have a problem or am plotting out an lvm change, i need to be able to quickly ascertain the device name (example: /dev/dsk/c1t0d1) that I'm going to need to run the command on.

I don't use SAM for lvm, everything i use is command line. I do use sam to gather information so I have a command list ready to go for system maintenance windows.

In the GUI I'd like to be able to right click the listing in sam's disk listing and get the device names, and other useful things like pvdisplay so i can get a quick look at the disk without too many clicks.

Any time or place I'm looking at a disk i should be able to select it and get vital information.

Hope this helps.

SEP

[Brian Markus]

1. First to understand your environment:
a. How many disks do you manage? 3000+
b. Approx. largest number of disks connected to a system? 200+
c. Do you use direct attached storage, SANs, or both? Both

2. Understanding disk (lun) device issues:
a. What are the issues you have in understanding you have the correct device (e.g. when selecting a disk for configuration or tracking down a problem)?
Itâ s a pain to use xpinfo (or equivalent) then map everything out to figure out whatâ s going on. Check it with the map from the disks systemâ ¦ etcâ ¦ Itâ s a bit tedious.

b. What are the issues you have mapping a device on the OS to the component within the storage system.
Specifically in the HP XP line, weâ ve had a lot of trouble mapping LUN/CU:LDEV to Device files on systems. We use an excel spreadsheet to keep things straight with tabs for each system. Itâ s really not very elegant, but it works.

3. Your input for making it better:
a. What type of information (e.g. lun number/name) would you need to see to help correctly identify your disk devices? And secondly, where in specific (e.g. CLI, application, etc.) would you want to see this data?
Personally Iâ d like to see a visual display of the disk system Visio Style, that I could click on then drill down into the disks. I could have colors assigned to systems and all disks associated to that system would be that color. From that Iâ d like to be able to drill down to the most detailed view if possible. Click on a disk then it gives me what the vg/lv/pv info for that disk might be. The EVA line has a bit of a clue as far as configuration / management, but it really didnâ t compete with the industrial strength SANâ s we looked at.

b. Any thoughts on a solution/feature (within OS or storage system) that could be provided to make this all easier in your environment?
See above.

4. Does your organization track disk configuration with a spreadsheet or web page (or other format: script, etc.) to represent the data in a specific view/format? If you are willing (or even allowed :) to send us a copy, please email: sam-invest@hpuxweb.hp.com. We are interested in looking at how you track this information and will analyze this for future enhancement, AND, not share it with anyone.
See above.
5. Any additional comments?
Iâ m glad someone from HP is considering upgrading the tool suite; SAM needs a facelift. The interface needs to go to a historical museum for computing (1980â s?). On a more productive note, one major complaint I have about HP-UX is the lack of open source tools available. The porting site is ok, but never has very many of the tools Iâ m looking for. I end up having to tweak source like mad and compile things manually. Iâ d like to see HP take an active roll in providing current versions of major released tools to the

[SAM TEAM]

Brian,

With 2b., do you only track the cu:ldev data with the device files or is there more?

SAM Team

[Geoff Wild]

1. Environment:

Don't know exact ammount of disks, but approx 20 - 25 TB of raw disk on EMC and Jamaica's and local. Largest physical disk's are 146GB.

2. Understanding disk (lun) device issues

Use EMC tools to assist in selection and problems.

3. Your input for making it better:

Be nice if HP can colaborate with EMC on tools - to make them better.

4. Does your organization track disk configuration with a spreadsheet or web page (or other format: script, etc.) to represent the data in a specific view/format?

No - online with EMC software. For documentation, we use cfg2html as well as Sysinfo301.

Rgds...Geoff

[Sundar_7]

1) I would like a way to display the LVM headers of a physical disk especially only the VGID/PVID of the disk. I know we can do it with adb and with the special lvm binary available from the solution center. But it would be really valuable if it is included in the core OS and will make the life easier to identify the multiple paths to the same LUN.

2) vgdisplay can include the cluster ID

3) One of the user's question couple of days ago highlighted one of the LVM's limitations (I believe). Are there any plans to include the ability to split off the mirrors of a VG in to a different VG without any downtime involved ?

4) Pardon if I am not fully understanding this issue. I understand there is a 8 LUN limitation on HP-UX and VBUS/target/LUN addressing is introduced to address this limitation. What is it preventing from HP-UX from being able to address more than 8 LUNS like say for ex Solaris.

[SAM TEAM]

Hi Geoff,

What/how in specific do you use in the EMC tools to assist in selection?

When you say colaborate with the EMC tools to make it better, in what way do you mean?

SAM Team

[Emanuele_4]

Hi...your question falls in the right time!

Yesterday I had to configure the new rp4440 server!

We have a Virtual Array 7410 with a suppementary enclosure (for a total of only 1TB)...I had to configure Volume groups, LV, ecc ecc.

I didn't use SAM to configure it and I used command line.

The big problem I find out is this:

When I make ioscan...I'm a little confused from identifying the disk path
/dev/dsk/c5t1d1

So I'd like to quickly understand how to identificate the disk path and the corresponding lun.

Yesterday I was using the disk from LUN0 ! ;-(...but, after, everything went fine!

Thanks for your question!

Emanuele

[Geoff Wild]

For selection/setup, we use ECC OE - a GUI based package that only runs on Windows...that allocates, and maps the disks to the HP servers. Then do a ioscan -fnC disk, insf -e disk, then use the command line to add disks to existing or new vg's. (sorry, don't use SAM at all for disk management).

Other tool I like to use is:

syminq (EMC tool to list disks)

For collabaration, I think what I mean is, to somehow get some of the functionality from EMC's ECC OE into HP-UX - things like performance metics (I know, can always use snmp).

Rgds...Geoff

[Victor BERRIDGE]

Hi,
Like many others on this forum, I got used to the idea it was best to use CLI rather than SAM when it comes to LVM mostly because its dead slow (why ?), then because you dont see in the disk device window what you do when you type ioscan -funC disk...
Now most admins here prefer to use sam to create new logical volume in already defined VGs, and leave to me the task of finding out which are the new disks (LUNs...)...

Now
4:
I have implemented on some boxes HiCommand Device Manager - Agent for HP-UX.
Seems to work fine...
Oh
1:
a)? (a couple of teras... 2 HDS9980v 10 HDS57XX 2 HDS5800)
b)60
c) both

All the best
Victor

[Mike Lancaster]

One thing that I would like to see is more info in the ioscan outputs.

For intance, it would help if you would show the stuff that you have to decode in your head now for the hardware path.

Example:
Have an option to show the domain, switch port, lun number etc.. N_portID etc for each device in the ioscan.

Have an option to show the serial number info from the disk in ioscan, just like EMC's INQ command.

Also, show the VGID from each volume and the date/time that it was last pvcreated (both avail in the disk header)

Also show the size in ioscan, maybe allow the user to choose between KB, MB, and GB.

[H.Merijn Brand (procura]

1.a. ±30 in total spread accross different machines and different OS (HP-UX 10.20, 11.00, and 11i, AIX 4.3.3 and 5.2) all shared accross NFS, and several disks in PC's and laptops (oth acting as File Server and workstation) with samba (M$Win) and NFS (Linux)
1.b. 4 to one system, unless you include NFS, which makes it up to 30
1.c. all disks are inside the machines they belong to. no external cabinets.

2.a. I have had none thus far. All is clear :)
2.b. See 2.a.

3.a. I need no more. all I need is there.
3.b. On-Line defragmentation, and fragmentation information.

4. No. I use the cstm output to make a hardware graph of all my HP systems, which is stored somewhere. Mainly for identifying what hardware is still available for new devices

5. No

Enjoy, Have FUN! H.Merij

[Bill Hassell]

Even on the smallest systems with a couple of disks, SAM spends a *LOT* of time doing nothing on the screen as you navigate between menus. I'm sure some of it is ioscan and [lpv]display commands that are invisible to the user. I'd like to see all ioscans inside SAM changed to -k after SAM has started, or perhaps get ioscan a new option to eliminate delays with 'blind' scans. ioscan -k shows what the kernel thinks is attached and once SAM is running, it is quite a waste of time to wait for discovery scans every time you traverse disk/filesystem menus.

[Brian Markus]

Here is what I'm tracking in the Spread sheet at the moment.

LUN
00

CU:LDEV
0:00

Device File
C__t0d0

Assignment - NODE1
tablesA_01.dbf

Assignment - NODE2
tablesA_01.dbf

Volume Group
/dev/oradata

Port Instance
CL1-A (NODE1) 5
CL2-A (NODE1) 7
CL1-E (NODE2) 8
CL2-E (NODE2) 9

I also have a map of the business copies as well as a global layout.

I hope this helps.

-Brian.

[Brian M Rawlings]

Hi, HP team. I don't know if you are still monitoring this thread, but there are a couple of things I'd like to see improved in SAM.

As an SE in VARland, I can't exactly answer your questions about how many disks I take care of, or how they are attached... it varies from day to day, customer to customer, and job to job.

But I use SAM and LVM a lot, and hope to provide some insightful (or inciteful?) suggestions.

1> Mirroring the boot disk is a scriptable set of very normal and well known commands. I have a script to do it, and I've seen others. ALL of the boot disk areas (LIF, lvols, etc) are handled by the script(s). This should be a "one click" (simple function) option in SAM, and should have been for a long time.

2> SAM does not provide all of the VG and LV setup options that are available in the command line... why on earth not? All the command line options have defaults, clearly spelled out in the man pages. Just add check boxes or pull-down menus for each command line option, with the defaults set just as the command line defaults are. It has always been inexplicable why the GUI is lobotimized, when they could just make it mirror the command line options.

3> When adding disks to a VG, either to create the VG or to extend it, SAM only lets you select one at a time. To create a VG with a dozen drives or LUNs, it is so slow in SAM I never even consider it. You should be allowed to high-light multiple drives, just like you can pick multiple SW items from a depot before actually doing an install with swinstall. This, plus the other suggestions above would make SAM a viable choice for VG, LV, and disk manipulation, in all cases, rather than in just a select few.

To leave on a high note, I'll say once and for all that SAM is far and away the best admin assist tool that ANY unix vendor includes with their product. Sun is getting better, but is still a distant third. SMIT has it's uses on the AIX side, but itn't nearly the useful friend that SAM has been.

Keep up the good work, and I hope you will consider the above improvements.

Regards, --bmr

[Prashant Zanwar_4]

I want to know if there is a possibility of geveloping a GUI which will be extensively be used for array and all other activity management related to it. Then it will have performance monitoring of array also. Can't it be great. TO initially view all array configuration. A tool which can really lookin any array and tell which LUN and which LDEV etc etc. Also how diskgroups are formed or even it will be doing this task too..Potentially it also can be integrated with LVM so that till FS creation all tasks can be acheived. And HP has seperate product to sell/market..

I dont know if I am overspoken..

Thanks
Prashant