[linux-lvm] disk naming

[Steven Lembark]

-- Matt Schillinger <mschilli at vss.fsi.com>

>
> this should be a simple question, but I can't find a direct discussion
> in the lvm documentation. I believe that i have found that LVM will find
> appropriate PV's regardless of their name (sda,sdb).. Is this true? Do i
> need devfs to ensure that i always have the same disk naming, or will
> LVM handle this for me?  I am currently using scsidev for naming
> purposes, but have found that vgcreate will not work with scsidev device
> names (/dev/scsi/sdh0-0c0i4l2p1)
> /dev/scsi/sd(host=0,scsiid=4,LUN=2,partition #=1)

sd[abcd] notation is based on the order which the kernel
finds devices on the bus. Adding a SCSI card or removing
disks will change the naming.

devfs allows using /dev/scsi/.../busX/.../targetY/.../partZ,
which will not change unless you shuffle the scsi cards :-)

I use it mainly because I prefer to know what I'm pointing
at -- memorizing the device letter conventions can be an
exercise in futility.

You can quickly convert from one naming convention to
the other if your root volume isn't on LVM: boot single
user, export the VG's and import them using the devfs
naming convention.


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Steven Lembark                               2930 W. Palmer
Workhorse Computing                       Chicago, IL 60647
                                            +1 773 252 1080