LTO Tape goes missing

Any requests with your Hardware.

Moderator: sepma

Post Reply
AndersG
Posts: 16
Joined: April 2nd, 2009, 8:02 am

LTO Tape goes missing

Post by AndersG » June 19th, 2014, 9:25 am

Sles 11.2 64 running on VMWare ESXi 5.5.0 SP1 (upgraded from 5.1.0).
Issue existed before upgrade, but before that it ran nicely for months.
Tape is a SAS HP Ultrium 448 drive on the host.

What happens is that lsscsi -g shows the drive, but suddenly /dev/nst0
is not there. Mt -f /dev/nst0 status says there is no such device.

Is there an easier way to bring it back than rebooting? I have tried unloading/loading st.ko, but that does not help

cliogp
Posts: 37
Joined: January 18th, 2006, 6:51 pm
Location: Waakirchen
Contact:

Re: LTO Tape goes missing

Post by cliogp » June 19th, 2014, 2:13 pm

Hello,

I think this is the wrong forum for this question, bcs it's a Linux OS problem. It's better to ask in a Linux OS forum.

Check your messages log and dmesg, if there any errors regarding tape device or SCSI.

May be udevadm is the best tool for you. See "man udevadm" . With udevadm you can reload all rules ( No warranty, I've never tried this).

Clio

AndersG
Posts: 16
Joined: April 2nd, 2009, 8:02 am

Re: LTO Tape goes missing

Post by AndersG » September 29th, 2014, 7:06 am

Nope it was not a Linux problem either, but a VMWare one, but since I bet more people than I have run into this. I Post the solution here as well:

The core issue is that the device is incorrectly detected by VMWare:

https://communities.vmware.com/thread/3 ... 0&tstart=0
http://kb.vmware.com/selfservice/micros ... Id=1026157

This is how it was:
~ # esxcli storage nmp device list
naa.500110a00122982e
Device Display Name: HP Serial Attached SCSI Tape (naa.500110a00122982e)
Storage Array Type: VMW_SATP_ALUA
Storage Array Type Device Config: {implicit_support=on;explicit_support=off; explicit_allow=on;alua_followover=on;{TPG_id=0,TPG_state=AO}}
Path Selection Policy: VMW_PSP_MRU
Path Selection Policy Device Config: Current Path=vmhba1:C0:T0:L0
Path Selection Policy Device Custom Config:
Working Paths: vmhba1:C0:T0:L0
Is Local SAS Device: false
Is Boot USB Device: false

Now "VMW_SATP_ALUA" is bad, bad, bad so it has to be changed, following the commands given in the links above. First find the actual name of the tape

~ # esxcli storage core device list
naa.500110a00122982e
Display Name: HP Serial Attached SCSI Tape (naa.500110a00122982e)
Has Settable Display Name: true
Size: 0
Device Type: Sequential-Access
Multipath Plugin: NMP
Devfs Path: /vmfs/devices/genscsi/naa.500110a00122982e
Vendor: HP
Model: Ultrium 2-SCSI
Revision: T61D
SCSI Level: 5
Is Pseudo: false
Status: on
Is RDM Capable: true
Is Local: false
Is Removable: true
Is SSD: false
Is Offline: false
Is Perennially Reserved: false
Queue Full Sample Size: 0
Queue Full Threshold: 0
Thin Provisioning Status: unknown
Attached Filters:
VAAI Status: unknown
Other UIDs: vml.0201000000500110a00122982e556c74726975
Is Local SAS Device: false
Is Boot USB Device: false
No of outstanding IOs with competing worlds: 32

In this case "Ultrium 2-SCSI"

Add a rule for it so that is "VMW_SATP_LOCAL" in the future:

esxcli storage nmp satp rule add --satp="VMW_SATP_LOCAL" --vendor="HP" --model="Ultrium 2-SCSI"

Have VMWare unclaim it, change C/T/L to match YOUR config:

esxcli storage core claiming unclaim -t location -A vmhba1 -C 0 -T 0 -L 0

Rescan:
esxcfg-rescan vmhba1

Check and you should have

~ # esxcli storage nmp device list
naa.500110a00122982e
Device Display Name: HP Serial Attached SCSI Tape (naa.500110a00122982e)
Storage Array Type: VMW_SATP_LOCAL
Storage Array Type Device Config: SATP VMW_SATP_LOCAL does not support device configuration.
Path Selection Policy: VMW_PSP_FIXED
Path Selection Policy Device Config: {preferred=vmhba1:C0:T0:L0;current=vmhba1:C0:T0:L0}
Path Selection Policy Device Custom Config:
Working Paths: vmhba1:C0:T0:L0
Is Local SAS Device: true
Is Boot USB Device: false

cliogp
Posts: 37
Joined: January 18th, 2006, 6:51 pm
Location: Waakirchen
Contact:

Re: LTO Tape goes missing

Post by cliogp » October 2nd, 2014, 10:59 am

Hello,

thank's for the feedback and very helpful information.

Clio

Post Reply