topic Re: FS in Operating System - HP-UX

FS

Sundar_7 — Tue, 17 Jul 2001 09:09:24 GMT

Hi all,,

Just want to know onething..

Say one File System /data is of 300MB which has

its physical extends over 2 disks

that is 150MB is there in /dev/dsk/c100t5d0

and 150MB is there in /dev/dsk/c100t6d0..

and it is not mirrored..

the question is that suppose if all of

/dev/dsk/c100t6d0 go for a toss and it is not

responding at all then what will the status

of the File System /data...

I guess that file System will go unusable..

But would like to know what exactly will

happen to the File System..

and what are the possible steps to restore

it back online..

I know this might be a rare case..

But I bet U geeks know the fix..

So let me also know..

Thanks in advance

Sundar

Re: FS

Ravi_8 — Tue, 17 Jul 2001 09:22:31 GMT

Hi,
if /dev/dsk/c100t6d0 crashes then whole /data file system tosses, since while booting or mounting the whole filesyetm will be considered, just not the disk. if you have the backup of the /data then even if /dev/dsk/c100t6d0 crashes you can recreate the /data on c100t5d0 with 300 mb size and can restore

Re: FS

James R. Ferguson — Tue, 17 Jul 2001 09:36:01 GMT

Hi:

In the case you describe, the file system will need to be reloaded from backup after replacing the failed disk:

1. Replace the disk
2. vgcfgrestore -n /dev/vgXX /dev/rdsk/c100t6d0
3. vgchange -a y /dev/vgXX
4. for N in ...do
newfs -F vxfs -b /dev/vgXX/rlvol${N}
5. Restore data to each lvol appropriately.

Regards!

...JRF...

Re: FS

Sundar_7 — Tue, 17 Jul 2001 09:39:07 GMT

Hi Ravi thanks for the reply..

But sorry I was not asking U what will happen

to /data as I also know it will go for a toss..

More over I would like to have the steps in

commands not in theory...and would like to have

the FS in both /dev/dsk/c100t5d0 and c100t6d0

after teplacing the disk..

See if U can help me out

Thanks

Sundar

Re: FS

James R. Ferguson — Tue, 17 Jul 2001 09:47:45 GMT

Hi (again) Sundara:

I should hasten to add that the 'newfs' and subsequent data restore, is only needed for those logical volumes that had extents on the failed/replaced disk.

...JRF...

Re: FS

Shahul — Tue, 17 Jul 2001 09:57:27 GMT

Hi Sundar

In this case U will not be able to access /data. U connect new HDD in same Ctlr with same ID and follow these steps.
#ioscan -fnC disk

Make sure that ur newly added HDD is listed.
#diskinfo /dev/rdsk/c100t6d0
Make sure that ur newly added HDD size model type ..etc are OK
#pvcreate -f /dev/dsk/c100t6d0
#vgchange -a n /dev/vgxx
#vgcfgretore -n /dev/vgxx /dev/dsk/c100t6d0
#vgchange -a y /dev/vgxx

Now U can just try mounting the lost file system. Check up whether any data is showing or not. If U get something U are lucky. Otherwise restore the entire lvol.

Best of luck

Shahul

Re: FS

SUDHAKARAN. — Wed, 18 Jul 2001 05:04:02 GMT

Hello Sundar,

Following are the steps to be followed for successful restoration.

1.Replace the failed disk in the same id so as to avoid confusion.
2.Boot the system in single user mode.
ISL>hpux -is
3.Restore the LVM header on to the disk.
#vgcfgrestore -n /dev/vgXX /dev/rdsk/cXtXd0
4.Now reactivate the Volume group so that the new disk can be attached,since it was'nt configured at the boot time.
#vgchange -a y /dev/vgXX.
5.Check which Logical Volumes has extents on the hard disk.
e.g
# pvdisplay -v /dev/dsk/c2d0s2 | more
.....
.....
--- Distribution of physical volume ---
LV Name LE of LV PE for LV
/dev/vg00/lvol3 50 50
/dev/vg00/lvol4 245 245
.....

6. You need to recreate the Filesystems first

# newfs -L /dev/vgXX/rlvolX

7. Then mount the filesystems to a mount point.
8. restore the backup.

Hope this helps.

Regards,
S.Sudhakaran.