SUSE Linux disk mount in sync or async mode.
Hi Experts,
I am using SUSE Linux 11 SP1
Can you please help me in identifying if disk (/mnt/data) is mounted in sync or async mode.
/dev/sdb1 /mnt/data ext3 defaults 1 2
defaults means async but how do I assure its really using async option.
# cat /etc/fstab
/dev/disk/by-id/scsi-36782
/dev/disk/by-id/scsi-36782
/dev/sdb1 /mnt/data ext3 defaults 1 2
proc /proc proc defaults 0 0
sysfs /sys sysfs noauto 0 0
debugfs /sys/kernel/debug debugfs noauto 0 0
usbfs /proc/bus/usb usbfs noauto 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
Thanks and regards,
Ranjit
I am using SUSE Linux 11 SP1
Can you please help me in identifying if disk (/mnt/data) is mounted in sync or async mode.
/dev/sdb1 /mnt/data ext3 defaults 1 2
defaults means async but how do I assure its really using async option.
# cat /etc/fstab
/dev/disk/by-id/scsi-36782
/dev/disk/by-id/scsi-36782
/dev/sdb1 /mnt/data ext3 defaults 1 2
proc /proc proc defaults 0 0
sysfs /sys sysfs noauto 0 0
debugfs /sys/kernel/debug debugfs noauto 0 0
usbfs /proc/bus/usb usbfs noauto 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
Thanks and regards,
Ranjit
cdfs
Simplest, that comes to my mind at the moment, would be to remount the disk with option sync, do some write-test and compare the times with the same tests when mounted with defaults. The write-speeds with sync should be much lower than with async.
Hi,
I need some commands to verify on Linux.
I found one command but not sure if this is the correct way to identify
# cat /proc/slabinfo |grep 'kio'
kioctx 9 20 384 10 1 : tunables 54 27 8 : slabdata 2 2 0
kiocb 335 465 256 15 1 : tunables 120 60 8 : slabdata 31 31 14
Note: second and third column values should be non zeros.
I have 15 sybase servers but the above command o/p is different on each server.
Thanks and regards,
Ranjit
I need some commands to verify on Linux.
I found one command but not sure if this is the correct way to identify
# cat /proc/slabinfo |grep 'kio'
kioctx 9 20 384 10 1 : tunables 54 27 8 : slabdata 2 2 0
kiocb 335 465 256 15 1 : tunables 120 60 8 : slabdata 31 31 14
Note: second and third column values should be non zeros.
I have 15 sybase servers but the above command o/p is different on each server.
Thanks and regards,
Ranjit
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I am not a OS expert. But below from ASE installation guide might be useful:
SuSE Raw Device Administration
Administer raw disk partitions in the /etc/raw file, which is a plain text file containing comments and examples for possible configurations:
# /etc/raw
#
# sample configuration to bind raw devices
# to block devices
#
# The format of this file is:
# raw<N>:<blockdev>
#
# example:
# ---------
# raw1:hdb1
#
# this means: bind /dev/raw/raw1 to /dev/hdb1
#
# ...
raw1:sda7
raw2:sda8
raw3:sda9
Once you have created them, bind the raw devices by starting them with the script /etc/init.d/raw:
# cd /etc/init.d
# sh raw start
bind /dev/raw/raw1 to /dev/sdb1... done
bind /dev/raw/raw2 to /dev/sdb2... done
bind /dev/raw/raw3 to /dev/sdb3... done
...
Use the chkconfig(8) utility to guarantee that the raw device binding occurs during any restart:
# /sbin/chkconfig raw on
SuSE Raw Device Administration
Administer raw disk partitions in the /etc/raw file, which is a plain text file containing comments and examples for possible configurations:
# /etc/raw
#
# sample configuration to bind raw devices
# to block devices
#
# The format of this file is:
# raw<N>:<blockdev>
#
# example:
# ---------
# raw1:hdb1
#
# this means: bind /dev/raw/raw1 to /dev/hdb1
#
# ...
raw1:sda7
raw2:sda8
raw3:sda9
Once you have created them, bind the raw devices by starting them with the script /etc/init.d/raw:
# cd /etc/init.d
# sh raw start
bind /dev/raw/raw1 to /dev/sdb1... done
bind /dev/raw/raw2 to /dev/sdb2... done
bind /dev/raw/raw3 to /dev/sdb3... done
...
Use the chkconfig(8) utility to guarantee that the raw device binding occurs during any restart:
# /sbin/chkconfig raw on
Hi Joe,
I found below lines in sybase log file which says particular device started in async mode but is there any command to know from linux OS that particular partition is mounted in async mode.
Virtual device 19 started using asynchronous (with DIRECTIO) i/o.
Hi Alpmoon,
I am using file system.
Thanks and regards,
Ranjit
I found below lines in sybase log file which says particular device started in async mode but is there any command to know from linux OS that particular partition is mounted in async mode.
Virtual device 19 started using asynchronous (with DIRECTIO) i/o.
Hi Alpmoon,
I am using file system.
Thanks and regards,
Ranjit
Well, here in the Sybase topic area we're mostly answering Sybase questions rather than SuSE questions. :)
Given that being opened for async I/O is not an attribute of the file but of the process issuing I/Os to the file (I'm calling a raw partition a file for sake of the argument :) ), I don't know how you'd even be able to tell from the O/S side.
The only way I've ever been able to have anyone (including Linux and Solaris admins) answer this question was to look at the ASE errorlog. Doesn't mean it's impossible, of course.
Given that being opened for async I/O is not an attribute of the file but of the process issuing I/Os to the file (I'm calling a raw partition a file for sake of the argument :) ), I don't know how you'd even be able to tell from the O/S side.
The only way I've ever been able to have anyone (including Linux and Solaris admins) answer this question was to look at the ASE errorlog. Doesn't mean it's impossible, of course.
Thanks Joe