Adding disks to a DS2300

 
Brad Marks
Super Advisor

Adding disks to a DS2300

I am sysadmin for a single rp5470 and have no experience in this regard -- our VAR has performed this type of task in the past, but we didn't have OnlineJFS.
I have 5 empty bays on my DS2300 (the 9 used ones all have 36GB drives -- one is a hot spare) and one filesystem (/dev/vg02/lvol1) is getting full.
I want to add additional drives and enlarge the logical volume.
All filesystems are RAID5.
I have OnlineJFS and an additional logical volume (/dev/vg03/lvol1) for creating a snapshot of six lvols for fbackup. I believe I need to enlarge the snapshot of /dev/vg02/lvol1 as well, right?
Here are the steps I believe I need to take (gleaned from these Forums):

1. pvcreate /dev/rdsk/cxtydz
>>> How do I come up with the values for x,y&z?
2. vgextend vg?? /dev/dsk/cxtydz
3. Use SAM to add space to existing filesystems; it is friendly and safe. You do not have to bring down a filesystem to extend its size.

Do these steps encompass all that I will need to do?
What about mirroring and striping; does OnlineJFS take care of this?
If I add two 36GB drives (I know they should all be the same size), how much additional space will I gain for the lvol?
It's not impossible -- it'll just cost more...
8 REPLIES 8
Fabian Briseño
Esteemed Contributor

Re: Adding disks to a DS2300

1. How do I come up with the values for x,y&z?

Do an # ioscan -fnC disk, you need to identify the disks you need.

2. this command looks good.

3. SAM will unmount the lvol you want to extend if you can afford this go ahead, if you cant afford to unmount the lvol do it by command line.
Knowledge is power.
Torsten.
Acclaimed Contributor

Re: Adding disks to a DS2300

You have a RAID5? So there is likely a RAID controller installed. Could you please post an

# ioscan -fn

and try if you can configure with "irm" command.

Hope this helps!
Regards
Torsten.

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Brad Marks
Super Advisor

Re: Adding disks to a DS2300

Yes, there is a RAID controller card.
With this configuration and using irm, can I still utilize OnlineJFS insofar as not having to unmount the filesystem prior to extending it?
Attached is the ioscan results.
Thanks!
It's not impossible -- it'll just cost more...
Henry Fauni
Valued Contributor

Re: Adding disks to a DS2300

Please send "vgdisplay -v" output. Did you check if you have any "free" extents on the existing VG's? How are your snapshots getting created?


Considering your ioscan output:

0/10/0/1.0.0.0 /dev/dsk/c4t0d0 /dev/rdsk/c4t0d0
0/10/0/1.0.0.1 /dev/dsk/c4t0d1 /dev/rdsk/c4t0d1
0/10/0/1.0.0.2 /dev/dsk/c4t0d2 /dev/rdsk/c4t0d2

Most likely, the next lun(s) you will configure with the new disks using irm will be lun 3. Then your device files will be:

/dev/dsk/c4t0d3 /dev/rdsk/c4t0d3

lun 4 will become /dev/dsk/c4t0d4 /dev/rdsk/c4t0d4

--------

/dev/vg02/lvol1 121835520 106050472 15663984 87.130548% /usr3

/dev/vg03/lvol1 121835520 106045464 15666704 87.128071% /snapshot/usr3
---------
/usr3 and /snapshot/usr3 are in separate Volume groups, /usr3 is in vg02, and the snapshot is in vg03. Which means, you have to create 2 LUNs, assigning one LUN each to each VG. You only have 5 slots available though! With 3 you can configure RAID5 (72 GB useable), 1 disk as parity, but with 2 left you have to configure RAID 1. (only 36GB useable)

Steps to increase /usr3:

1. pvcreate /dev/rdsk/c4t0d3
2. vgextend vg02 /dev/dsk/c4t0d3
3. vgdisplay -v vg02
Then look for "Total PE" value.
Step below will use up all space in vg02. Since you only have 1 logical volume on this VG, you can allocate everything to it.
4. lvextend -l total_pe /dev/vg02/lvol1
5. lvdisplay -v /dev/vg02/lvol1
Look for LV Size (Mbytes) value. Let's call this=size
Step below will extend filesystem without unmounting filesystem if you have OnlineJFS.
6. fsadm -F vxfs -b sizem /usr3
Note the "m" multiplier on the size, and also note we used the mount point /usr3.

Good luck!

Brad Marks
Super Advisor

Re: Adding disks to a DS2300

I'm looking into reconfiguring the three logical drives on the RAID 4si card. Since I currently have eight drives I will need to create two arrays of six drives each (yes, I am adding four drives) and span them.

When I look at irdiag -v output, it does not state which physical drives are associated to a given logical drive. For each logical drive shown, it lists all physical drives as belonging to Span 0.

In the RAID 4si documentation, it only talks about creating logical drives from available (RDY) physical drives. One of my logical drives is only 5GB in size, but all drives are 36GB, so there has to be a means of carving up available disk space into different logical drives, right?!?

I've attached irdiag -v output for your perusal.

Thanks for any help here.
-Brad
It's not impossible -- it'll just cost more...
Torsten.
Acclaimed Contributor

Re: Adding disks to a DS2300

"... it does not state which physical drives are associated to a given logical drive..."

It does.

You have 1 RAID 5 spanning 8 drives. Each logical drive is located on this RAID (on all disks).

Hope this helps!
Regards
Torsten.

__________________________________________________
There are only 10 types of people in the world -
those who understand binary, and those who don't.

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No support by private messages. Please ask the forum!

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Brad Marks
Super Advisor

Re: Adding disks to a DS2300

Thank you, Torsten.
My (hopefully) last question is: When in the irm, how do I create different logical drives? As I stated, the RAID 4si documentation only talks about creating logical drives from available (RDY) physical drives. But, as you stated, logical drives are a part of the RAID and are made up of all drives. I don't get it!
Here's the link to the documentation I'm referring to:
http://docs.hp.com/en/J6173-90007/J6173-90007.pdf
See step 3 on page 94 through step 4 on page 97.
Thanks!
It's not impossible -- it'll just cost more...
Brad Marks
Super Advisor

Re: Adding disks to a DS2300

Figured it out once in the IRM.
It's not impossible -- it'll just cost more...