Raw logical volume for sybase

[Husaini_1]

Hi guys/experts,

my dba team request me to provide them new raw logical volume in hpux for sybase purposes. The request as below:

a) 2 GB ( for Data)
b) 1 GB (for Log)

The problem is, i have done create lv and give sybase permission to lv

# lvcreate -L 2000 -n lvol24 vg02
# lvcreate -L 1000 -n lvol25 vg02
# chown sybase:sybase rlvol24
# chown sybase:sybase rlvol25
# ls -la
brw-r----- 1 root sys 64 0x020016 May 15 15:57 lvol24
brw-r----- 1 root sys 64 0x020017 May 17 07:26 lvol25
crw-r----- 1 sybase sybase 64 0x020016 May 15 15:57 rlvol24
crw-r----- 1 sybase sybase 64 0x020017 May 17 07:26 rlvol25

but dba having problem to allocate the space to the database device. Error:

1> disk init name="cifdata3", physname="/dev/vg02/rlvol24", vdevno=43,
1> size=512000
2> go

Msg 5115, Level 16, State 1:
Server 'IBSPROD', Line 1:
I/O error during disk initialization. PHYSNAME '/dev/vg02/rlvol24' may be incorrect or 1023999 (VSTART + SIZE) may exceed the size of the device. Please consult the SQL Server error log for more details.

1) Can expert out site there tell me what is went wrong with my lv. Is it correct the step to create raw lv for sybase/db purposes?

2) Do i need to newfs the lv?

3) Search in forum and found raw divice means logical volume without defining fstype(vxfs, hfs...). But how to create it without define fstype. I create the lv and check using fstyp and found out it automatically define the lv type as vxfs.

[TTr · Accepted solution]

The following might help
1. Make the block devices lvol24, lvol25 owned by sybase:sybase. I don't know if it is required but just to be safe.
2. Verify the size of the volumes with "lvdisplay -v /dev/vg02/lvol24" and for "lvol25".
3. Verify that there are no write errors on the volumes by performing a write test
"dd if=/dev/zero of=/dev/vg02/rlvol24 bs=1024k"
Repeat for rlvol25.
4. Ask the dba to check that the "512000" he is using multiplied by the sybase block size which he/she should know what it is, does not exceed the lvol size. Ask the dba to use a smaller number such as "size=100" etc.
5. You are correct there is no need to do "newfs"

[TTr]

One more thing, verify that /dev/vg02 has permission mode 755 so that the sybase user can traverse it to get to the rlvols.

[Husaini_1]

i have tried ur suggestion for dd part:

root@edsprod:[/dev/vg02]
>> dd if=/dev/zero of=/dev/vg02/rlvol24 bs=1024k
I/O error
2001+0 records in
2000+1 records out

root@edsprod:[/dev/vg02]
>> dd if=/dev/zero of=/dev/vg02/rlvol25 bs=1024k
I/O error
1001+0 records in
1000+1 records out

[Husaini_1]

Thats mean nothing wrong with the disk.

By the way, for question no 3) Search in forum and found raw divice means logical volume without defining fstype(vxfs, hfs...). But how to create it without define fstype. I create the lv and check using fstyp and found out it automatically define the lv type as vxfs.

Is there anyone know about this?

[TTr]

I would not worry about the fstyp output. I tried creating two logical volumes (without newfs) and one showed up as fstyp vxfs and the other showed up as unknown. It is probably caused by old structures that were on the PV before or by coincidence with whatever the fstyp command is reading from the volume.

You can go ahead and newfs the volumes with vxfs or hfs if it makes you feel better, it does not make any difference. When the sybase dba initializes the lvols with the "disk init" command, sybase overlays them with whatever structure they are using and destroys any vxfs or hfs structure that was there before.

Did you check all the other items I mentioned?

[Husaini_1]

Hi TTr,

1. Done make block device as sybase:sybase
2. Done verify the size of the volumes
3. Done verify that there are no write errors on the volumes
4. Already ask DBA about "512000". I will let you know the result.

[TTr]

DOn't forget the 755 permission mode of /dev/vg02.

[Husaini_1]

Problem solve. i follow what u suggest. Im not sure what went wrong but it okay now. they can see the disk. Thanks.

[Husaini_1]

Thanks a lot