what are cciss devices? - Redhat
This is a discussion on what are cciss devices? - Redhat ; real dumbo question here - apologies in advance!
I've googled to no avail... I'm seeking some numpty giude to what a
cciss device is... e.g. I can see that some systems have hard drives /
dev/sda, /dev/sdb etc... but then ...
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what are cciss devices?
real dumbo question here - apologies in advance!
I've googled to no avail... I'm seeking some numpty giude to what a
cciss device is... e.g. I can see that some systems have hard drives /
dev/sda, /dev/sdb etc... but then also /dev/cciss/c0d0 or /dev/cciss/
c0d1 etc...
these cciss devices do not show in fdisk -l... so where do they come
from?
I presumed SAN but from what I can find SAN disks shoud get presented
as a scsi disk eg /dev/sdc or whatever ..
just trying to learn!
cheers
ian
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Re: what are cciss devices?
.... perhaps a better questiion might be why can I see just three sd
devices with fdisk -l, bjut 5 disk devices including two cciss devices
with lvmdiskscan?
(I have now found that the cciss devices are compaq raid devices :-)
# fdisk -l
Disk /dev/sda: 107.3 GB, 107372544000 bytes
255 heads, 63 sectors/track, 13053 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 1 13053 104848191 83 Linux
Disk /dev/sdb: 53.6 GB, 53686272000 bytes
255 heads, 63 sectors/track, 6526 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 6526 52420063+ 83 Linux
Disk /dev/sdc: 53.6 GB, 53686272000 bytes
255 heads, 63 sectors/track, 6526 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 6526 52420063+ 83 Linux
]# lvmdiskscan
lvmdiskscan -- reading all disks / partitions (this may take a
while...)
lvmdiskscan -- /dev/sda1 [ 99.99 GB] free whole disk
lvmdiskscan -- /dev/sdb1 [ 49.99 GB] free whole disk
lvmdiskscan -- /dev/sdc1 [ 49.99 GB] free whole disk
lvmdiskscan -- /dev/cciss/c0d0p1 [ 99.59 MB] free whole disk
lvmdiskscan -- /dev/cciss/c0d1p1 [ 23.84 GB] free whole disk
lvmdiskscan -- 5 disks
lvmdiskscan -- 5 whole disks
lvmdiskscan -- 0 loop devices
lvmdiskscan -- 0 multiple devices
lvmdiskscan -- 0 network block devices
lvmdiskscan -- 24 partitions
lvmdiskscan -- 0 LVM physical volume partitions
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Re: what are cciss devices?
sorry ... you can tell its Friday!
System is RedHat ES 3
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Re: what are cciss devices?
didds wrote:
> ... perhaps a better questiion might be why can I see just three sd
> devices with fdisk -l, bjut 5 disk devices including two cciss devices
> with lvmdiskscan?
> ]# lvmdiskscan
> lvmdiskscan -- reading all disks / partitions (this may take a
> while...)
> lvmdiskscan -- /dev/sda1 [ 99.99 GB] free whole disk
> lvmdiskscan -- /dev/sdb1 [ 49.99 GB] free whole disk
> lvmdiskscan -- /dev/sdc1 [ 49.99 GB] free whole disk
> lvmdiskscan -- /dev/cciss/c0d0p1 [ 99.59 MB] free whole disk
> lvmdiskscan -- /dev/cciss/c0d1p1 [ 23.84 GB] free whole disk
> lvmdiskscan -- 5 disks
> lvmdiskscan -- 5 whole disks
> lvmdiskscan -- 0 loop devices
> lvmdiskscan -- 0 multiple devices
> lvmdiskscan -- 0 network block devices
> lvmdiskscan -- 24 partitions
> lvmdiskscan -- 0 LVM physical volume partitions
>
It sounds like fdisk is returning only physical devices, while
lvmdiskscan is returning both your physical devices, and logical RAID
devices. The cciss/c0d0p1 and cciss/c0d1p1 references are to:
controller0, disk0, partition1 and controller0, disk1, partition1.
James http://cronus.ath.cx
