topic Re: /dev/disk/disk3 and /dev/dsk/c0t0d0? in Operating System - HP-UX

/dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 15:14:19 GMT

I just got a new rx2660 serer with hpux11i, v3. when I do ioscan -fnC disk, I got the following output:

/dev/dsk/c0t0d0 /dev/rdsk/c0t0d0
/dev/dsk/c0t0d0s1 /dev/rdsk/c0t0d0s1
/dev/dsk/c0t0d0s2 /dev/rdsk/c0t0d0s2
/dev/dsk/c0t0d0s3 /dev/rdsk/c0t0d0s3

however, when I do ll /dev/disk/disk3*, i got the following:
/dev/disk/disk3
/dev/disk/disk3_p1
/dev/disk/disk3_p2
/dev/disk/disk3_p3

I understand 11i,v3 uses persistence device file names, but how come disk3's are not included in ioscan?

also, there are 8x146gb drive physically as I can see, but it seems only one drive appeared in ioscan -fnC.

confused....

Thanks,

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 15:19:04 GMT

All the legacy parameters for ioscan will produce results just like in previous versions.

There are new parameters for new features.

Compare

# ioscan -fn

and

# ioscan -fN

for exapmle.

To see the relation between
cxtydz
and diskx
devices, use

# ioscan -m dsf

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 15:25:37 GMT

Another example:

$ ioscan -fkm lun
Class I Lun H/W Path Driver S/W State H/W Type Health Description
======================================================================
disk 4 64000/0xfa00/0x0 esdisk CLAIMED DEVICE online HP
DG072A8B54
0/4/1/0.0x5000c5000216de6d.0x0
/dev/disk/disk4 /dev/rdisk/disk4
...

Read "man ioscan".

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 15:46:45 GMT

Okay. I see. disk3 and c0t0d0 is identical.

But, could you please explain to me what is "LOGICAL VOLUME"? and why I can see 8 physical internal drive, each with 146G, but only one drive disk3 is shown from ioscan, with about 573g in total?

Thanks,

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 15:50:43 GMT

"logical volume" sounds like a smartarray is installed.

Please post

# ioscan -fn

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 15:51:32 GMT

when I saying "LOGICAL VOLUME", it means the term in the result of ioscan -fnC.

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 15:54:51 GMT

If you find a device like

/dev/ciss3
(or whatever number)

run this command and post the result

# saconfig /dev/ciss3

# sautil /dev/ciss3

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 16:22:00 GMT

Torsten,

It doesn seem "smartarray" installed. I don't have to know it in detail for now. But, if I reinstall OS to be 11i v2, will I see all 8 disks back?

also, could you please send me the link for the concept of "smartarray"?

Thanks for all your help,

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 16:28:37 GMT

If you would send the commands output (see above) I can help you to clarify ... insufficient input until now ;-)

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 16:34:43 GMT

About smartarrays:

http://docs.hp.com/en/J6369-90050/index.html

RAID Technology Overview: HP Smart Array RAID Controllers

This controller will manage the disks - you cannot see particular disks, but logical drives ONLY.

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 16:58:04 GMT

Hi Torsten,

Thanks for your patience. It would be hard to forward all outputs here, because I only have MP connections, so, it is not so easy to transfer the output over here. Please find the output from saconfig, if it is going be enough? Again, I don't know SmartArray, but when I wipe out 11iv3, and after put 11iv2 on, what disks should look to me? should I get 8 disks, or still going to be logical volume as it looks now on 11iv3? Please let me know if you still need other infor. Thanks!

# saconfig /dev/ciss0

******************** SmartArray RAID Controller /dev/ciss0 ********************

Auto-Fail Missing Disks at Boot = disabled
Cache Configuration Status = cache enabled
Cache Ratio = 25% Read / 75% Write

---------- PHYSICAL DRIVES ----------

Location Ct Enc Bay WWID Size Status

Internal 1I 1 8 0x5000c50005d56da9 146.8 GB OK
Internal 1I 1 7 0x5000c50007f155d5 146.8 GB OK
Internal 1I 1 6 0x5000c50003ea1aed 146.8 GB OK
Internal 1I 1 5 0x5000c50003e34815 146.8 GB OK
Internal 2I 1 4 0x5000c50005d66e41 146.8 GB OK
Internal 2I 1 3 0x5000c50005d34435 146.8 GB OK
Internal 2I 1 2 0x5000c50005d451c5 146.8 GB OK
Internal 2I 1 1 0x5000c5000ab0424d 146.8 GB OK

---------- LOGICAL DRIVE 0 ----------

Device File = c0t0d0
RAID Level = 1+0
Size = 559929 MB
Stripe Size = 128 KB
Status = OK

Participating Physical Drive(s):

Ct Enc Bay WWID
1I 1 8 0x5000c50005d56da9
1I 1 7 0x5000c50007f155d5
1I 1 6 0x5000c50003ea1aed
1I 1 5 0x5000c50003e34815
2I 1 4 0x5000c50005d66e41
2I 1 3 0x5000c50005d34435
2I 1 2 0x5000c50005d451c5
2I 1 1 0x5000c5000ab0424d

Participating Spare Drive(s):

None

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 16:59:51 GMT

please find the following the portion of the command sautil /dev/ciss0

#sautil /dev/ciss0

...................

---- SAS/SATA DEVICE 2I:1:3:0x5000c50005d34435 [DISK] ------------------------

Connector Location............................... internal
Connector........................................ 2I
Enclosure........................................ 1
Bay.............................................. 3
WWID............................................. 0x5000c50005d34435
Device Type...................................... DISK
Disk Capacity.................................... 146.8 GB
Device Status.................................... OK
Device Vendor ID................................. HP
Device Product ID................................ DG146ABAB4
Device Serial Number............................. 3NM249Q200009747LB5B
Device Firmware Version.......................... HPDC
Reserved Area (cfg/status info).................. 33554.4 KB (33.6 MB)
Block Size (bytes/sector)........................ 512 bytes
M&P Data Stamped?................................ yes
Last Failure Reason.............................. none

Physical Disk Flags:
Disk present and operational................... yes
Non-disk device detected....................... no

S.M.A.R.T. supported........................... yes
S.M.A.R.T. errors (in factory M&P data)........ no
S.M.A.R.T. enabled............................. yes
S.M.A.R.T. errors (in powerup M&P data)........ no
Attached to external connector................. no
Configured in a logical drive.................. yes
Configured as a spare disk..................... no
Disk write cache enabled at spin up............ no

Supports redundant controller operation........ no
Disk write cache enabled in current page....... no
Disk write cache disabled in default page...... yes

---- SAS/SATA DEVICE 2I:1:2:0x5000c50005d451c5 [DISK] ------------------------

Connector Location............................... internal
Connector........................................ 2I
Enclosure........................................ 1
Bay.............................................. 2
WWID............................................. 0x5000c50005d451c5
Device Type...................................... DISK
Disk Capacity.................................... 146.8 GB
Device Status.................................... OK
Device Vendor ID................................. HP
Device Product ID................................ DG146ABAB4
Device Serial Number............................. 3NM2331K00009748WHV1
Device Firmware Version.......................... HPDC
Reserved Area (cfg/status info).................. 33554.4 KB (33.6 MB)
Block Size (bytes/sector)........................ 512 bytes
M&P Data Stamped?................................ yes
Last Failure Reason.............................. none

Physical Disk Flags:
Disk present and operational................... yes
Non-disk device detected....................... no

S.M.A.R.T. supported........................... yes
S.M.A.R.T. errors (in factory M&P data)........ no
S.M.A.R.T. enabled............................. yes
S.M.A.R.T. errors (in powerup M&P data)........ no
Attached to external connector................. no
Configured in a logical drive.................. yes
Configured as a spare disk..................... no
Disk write cache enabled at spin up............ no

Supports redundant controller operation........ no
Disk write cache enabled in current page....... no
Disk write cache disabled in default page...... yes

---- SAS/SATA DEVICE 2I:1:1:0x5000c5000ab0424d [DISK] ------------------------

Connector Location............................... internal
Connector........................................ 2I
Enclosure........................................ 1
Bay.............................................. 1
WWID............................................. 0x5000c5000ab0424d
Device Type...................................... DISK
Disk Capacity.................................... 146.8 GB
Device Status.................................... OK
Device Vendor ID................................. HP
Device Product ID................................ DG146BB976
Device Serial Number............................. 3NM50ZD900009836G0RH
Device Firmware Version.......................... HPDC
Reserved Area (cfg/status info).................. 33554.4 KB (33.6 MB)
Block Size (bytes/sector)........................ 512 bytes
M&P Data Stamped?................................ yes
Last Failure Reason.............................. none

Physical Disk Flags:
Disk present and operational................... yes
Non-disk device detected....................... no

S.M.A.R.T. supported........................... yes
S.M.A.R.T. errors (in factory M&P data)........ no
S.M.A.R.T. enabled............................. yes
S.M.A.R.T. errors (in powerup M&P data)........ no
Attached to external connector................. no
Configured in a logical drive.................. yes
Configured as a spare disk..................... no
Disk write cache enabled at spin up............ no

Supports redundant controller operation........ no
Disk write cache enabled in current page....... no
Disk write cache disabled in default page...... yes

******************************************************************************
**** End of SAUTIL Output ****
******************************************************************************

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Tue, 08 Jul 2008 17:04:17 GMT

This must be a smartarray P400.

A smartarray controller will "hide" physical disks from the user, but you can create logical drives and use them just like physical disks.

Re-installing the OS will NOT change anything.

Currently you have a logical drive mirrored over all your disks - ~500GB in size.

This is just not good.

I would suggest to delete it (save your data if needed!) and create a first logical drive (maybe ~25-40 GB) for the boot disk.

Then re-install the OS.

Procedures are here:

http://docs.hp.com/en/J6369-90072/ch03s03.html

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 19:43:34 GMT

Torsten,

I would like to talk to you about configurations that I am going to setup.
As you said, we are currently using all 8 physical disks (8x146gb) as a logical volume, and this volume is configured as a boot disk with the size of 560gb(raid 1+0).

Here is what I am going to do, or my questions:

1. in order to reconfigure the logical drive, I have to wipe out the whole O.S. since all 8 disks have been used for the boot disk. Am I correct here? Is there any way to shrink the size of the logical drive without deleting data or wiping out O.S?
2. I am going to use 2 physical disks for the boot disks (raid 1+0), a spare one, and the rest 5 disks for Raid 5 logical drive. Is there any problem for this configuration?
3. I thought about your suggestion on the size of the boot disk(max. 40g), however, since we have 146 gb each disk, if I use 40G, then I only use the portion of the physical disks. I know I can use two logical drives to share the same physical one, but would that potentially pose any problems? since one of logical drive is for the boot disk?
4. One spare disks for 2 or more logical drives, would that be alright?

thanks for your input.

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Tue, 08 Jul 2008 20:29:41 GMT

5. with smartarray, what should I do to setup alternate boot disk, is this going be another logical drive, if it is then I have to use another pair of physical disks (raid 1+0), then 4 entire physical disks will be sued, if I dont' want to share 2 logical drives on the same physical disk. Am I right?

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Wed, 09 Jul 2008 09:58:59 GMT

Shrink the space may cause serious problems, so better take an ignite backup, configure the logical drives and restore.

Your config with RAID 0+1 and RAID 5 sounds good.

No need to use LVM mirror, because your drive will be mirrored (by hardware) already.

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Wed, 09 Jul 2008 10:30:21 GMT

Hi Torsten,

On page 43 of the document you forwarded to me, there is such setnence as following:

â ¢ HP strongly recommends having an alternate boot device available.

Please let me know what alternate boot device he is talking about?

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Wed, 09 Jul 2008 13:00:42 GMT

What document was it?

IMHO a mirrored drive is enough. This protects you agains disk failures (not root user failures ;-))

For this you need an (ignite-) backup.

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Hanry Zhou — Wed, 09 Jul 2008 13:12:59 GMT

Torsten,

I understand what you have said about the hawardware protection for the boot disk.

Please check out the page 43 in this this document :http://docs.hp.com/en/J6369-90072/J6369-90072.pdf

It states that â ¢ HP strongly recommends having an alternate boot device available.

Thanks for hanging with me.

Re: /dev/disk/disk3 and /dev/dsk/c0t0d0?

Torsten. — Wed, 09 Jul 2008 13:33:24 GMT

This is in the chapter "Configuring a Smart Array Series Controller as a Boot Device", so I guess the meaning is that it may be easier to configure the RAID from an running hp-ux, because it may be difficult to configure it offline on a HP9000 RISC based server.

Anyway, it's easier if you have an Integrity like yours.

To have 2 disks mirrored (in this case by hardware) is really safe enough.

Everything else will be overkill (e.g. use LVM to mirror vg00 to another set of disks).