topic Re: VOL vs RVOL in Operating System - HP-UX

VOL vs RVOL

Emanuele De Angelis — Thu, 08 Jan 2004 10:32:12 GMT

HI,
Which is the difference between RVOL and VOL?
Thanks

Re: VOL vs RVOL

Pete Randall — Thu, 08 Jan 2004 10:33:59 GMT

rvol is the raw, or unbuffered, device.

Pete

Re: VOL vs RVOL

Steven E. Protter — Thu, 08 Jan 2004 10:35:31 GMT

when extending or creating a logical volume under lvm, you work on te lvol

When creating or extending a filesystem you work on the rvol

SEP

Re: VOL vs RVOL

G. Vrijhoeven — Thu, 08 Jan 2004 10:36:32 GMT

Hi,

The differense is a character device and a block device. A character is device (raw) is unbuffered and a block devide is.

Gideon

Re: VOL vs RVOL

Shahul — Thu, 08 Jan 2004 10:41:32 GMT

Hi,

rvols are raw volumes. Some of the applications uses volumes as raw partitions, for eg. oracle, sybase ..etc. We use the same name while creating a new filesystem on a volume.

vols are block devices. A mounted filesystem uses block device file. Anyway when you create a volume under LVM, both of these device files are created.

Hope this helps
Shahul

Re: VOL vs RVOL

Todd McDaniel_1 — Thu, 08 Jan 2004 10:41:51 GMT

I think your asking about rlvol and lvol?

/dev/vg00/rlvol and /dev/vg00/lvol

One example is when the raw device is used when you create a new filesystem with newfs:

newfs -F vxfs /dev/vgXX/rvlol

LVOL is the "cooked" version of the logical volume. This is what you use to mount filesystems... It is actually a tangible device by unix commands to be mounted and queried...

Kind of a simplistic answer but I hope it helps you.

here is a link to docs.hp.com ... http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90672/B2355-90672_top.html&con=/hpux/onlinedocs/B2355-90672/00/00/30-con.html&toc=/hpux/onlinedocs/B2355-90672/00/00/30-toc.html&searchterms=rlvol%7clvol&queryid=20040108-084050

Re: VOL vs RVOL

Rajeev Shukla — Thu, 08 Jan 2004 19:50:42 GMT

The main difference is that RVOL is character device, means when you access the device with this name the I/O is in stream mode character based and hence is unbuffered, where as if you use VOL which is block device the I/O is in block mode and is buffered.

Re: VOL vs RVOL

Sunil Sharma_1 — Fri, 09 Jan 2004 02:16:10 GMT

Hi,

as everybody said about lvol and rlvol the main difference is lvol is block device file and rlvol is character device file.

We can compare these with rdsk and dsk device files only difference is that these are logical not physical.

Sunil