Thank you for your respond.
I am still having problems using sar.
/proc/partitions do not shed any light on sar output.
Here is the contents of it.
I see similar entries in this file and df -k. But sar output does not show any of them.
ls -l on each /dev file only shows when entries in /dev were created.
If you want to know the device name corresponding to the one displayed in the sar output, you only have to match the major and minor node numbers in sar list to the corresponding entry in /proc/partitions.
The ls -l ouput also gives you those numbers, which are essential to identify the device node linux uses to address every device. You only have to use them in the /proc/partitions output to find out the device name.
For example, according to the sar output listing you attached in your first post, you have a device managed by the device mapper that is referenced in sar output by the name dev253-1. That means that the major number is 253 (corresponding to devices managed the the device mapper software layer) and the minor is 1, sequential number used to identify the specific device managed by the same driver.
You now go to the /proc/partitions file and find out from there that the device name corresponding to the sar entry is dm-1. This is the low level internal name used by the device mapper driver. To find out the high level name used in /etc/fstab corresponding to the dm-1 you go to /dev/mapper directory and run ls -l.
There you will see the high level device name to the right and instead of sizing data you will find the device major and minor nodes.
That´s it.
I see you are using file systems located in luns defined in external storage devices (san), but that fact doesn´t change the linux way of assigning them a device node and a device name.
FYI: The /dev/disk directory hierarchy contains several subdirectories that list all the disk devices (disks and partitions) the kernel has currently recognized in your system. You can reference them using several approaches:
-label
-uuid
-path
-id
Also, keep in mind that sar -d gives statistic data for every block device the kernel knows about, independently of the driver managing them. In other words, if you have set up LVM LVs out of PVs defined on physical partitions located in local or remote disks/luns, you will find sar statistics for the LVs, for the physical partitions and for the physical disk/lun as a whole.
To ease the reading of sar ouput, filter it through grep.
On the other side, if you are interested in knowing the exact meaning of every statistic datum displayed in every sar entry, read the manual pages. They are explained with full details there.