Run dr_install.sh script got error for Readahead size of sda (/dev/sdb1,/dev/sdb2) is too low for typical systems: 256 < 2048

Document ID : KB000017745
Last Modified Date : 14/02/2018
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Run dr_install.sh script, got error for Readahead size of sda (/dev/sdb1,/dev/sdb2) is too low for typical systems: 256 < 2048


 	IM 2.3.4 	
 	Vertica 7 

When user tries to install/upgrade existing Vertica 6 to Vertica 7 via running script


 	./dr_install.sh -p drinstall.properties 

It shows up this error:

"
Failures during local (OS) configuration for verify-10.130.238.131.xml:
FAIL (S0020): https://my.vertica.com/docs/7.0.x/HTML/index.htm#cshid=S0020
Readahead size of sda (/dev/sdb1,/dev/sdb2) is too low for typical
systems: 256 < 2048
"

This is because Vertica 7 requires the Disk readahead by set to at least 2048.

User can run this command to check their disk:


 	# blockdev --report 	
 	RO RA SSZ BSZ StartSec Size Device 	
 	rw 2048 512 4096 0 128849018880 /dev/sda 	
 	rw 2048 512 1024 2048 524288000 /dev/sda1 	
 	rw 2048 512 4096 1026048 63899172864 /dev/sda2 	
 	rw 2048 512 4096 125829120 64424509440 /dev/sda3 	
 	rw 2048 512 4096 0 110066925568 /dev/dm-0 	
 	rw 2048 512 4096 0 17179869184 /dev/dm-1 	
 	rw 256 512 4096 0 134217728000 /dev/sdb 	
 	rw 256 512 1024 63 567512064 /dev/sdb1 	
 	rw 256 512 1024 1108485 69799726080 /dev/sdb2 

To modify above readahead value, use can run this command:


 	blockdev --setra <RA value> /dev/sdb 

For example:


 	blockdev --setra 2048 /dev/sdb 

then run the verify command again to check:


 	blockdev --report 	
 	RO RA SSZ BSZ StartSec Size Device 	
 	rw 2048 512 4096 0 128849018880 /dev/sda 	
 	rw 2048 512 1024 2048 524288000 /dev/sda1 	
 	rw 2048 512 4096 1026048 63899172864 /dev/sda2 	
 	rw 2048 512 4096 125829120 64424509440 /dev/sda3 	
 	rw 2048 512 4096 0 110066925568 /dev/dm-0 	
 	rw 2048 512 4096 0 17179869184 /dev/dm-1 	
 	rw 2048 512 4096 0 134217728000 /dev/sdb 	
 	rw 2048 512 1024 63 567512064 /dev/sdb1 	
 	rw 2048 512 1024 1108485 69799726080 /dev/sdb2 

Once the Disk readahead been set, above install error should be gone.