Turn off write barriers on ext4 whiche FS is mounted

Posted by user462982 on Server Fault See other posts from Server Fault or by user462982
Published on 2011-11-27T14:14:59Z Indexed on 2011/11/27 17:55 UTC
Read the original article Hit count: 205

Filed under:

lvm

|

mount

|

ext4

|

write

I am doing some IO intensive DB imports that run for several days now and the IO performance has dropped tremendously over times. The DB data files (log files) are on an ext4 formatted logical volume which is mounted with default options (did not specify something special in fstab). Since I just learned that ext4 enables write barriers by default: Q: Is there some way to disable write barriers online (i.e. while the file system is in use), because I cannot interrupt the import and don't want to restart it again. I am aware that

write barriers might not be the only thing impeding performance
it is a bad idea to have write barriers disabled on journalling file systems if data safty is important (e.g. on a production system)

© Server Fault or respective owner

Related posts about lvm

Unix LVM: how to resize root lvm

as seen on Server Fault - Search for 'Server Fault'
I took over a virtual server at work after a co-worker left. He, however, setup the server incorrectly at multiple stages and im cleaning them up as I run into them... Currently I realized that the file system is broken in half onto 2 logical volumes both at 50gb. One is mounted as the root directory… >>> More
RAID5 over LVM on Ubuntu Server 12.04.3

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I'm trying to create a RAID5 software array using LVM. I use VirtualBox as I'm only learning how LVM works. So I've created 4 virtual SCSI drives and then did the following: pvcreate /dev/sd[b-e] vgcreate /dev/sd[b-e] raid5_vg lvcreate --type raid5 -i 3 -L 1G -n raid_lv raid5_vg However, I get… >>> More
Preseeding Ubuntu partman recipe using LVM and RAID

as seen on Server Fault - Search for 'Server Fault'
I'm trying to preseed Ubuntu 12.04 server installation and created a recipe that would create RAID 1 on 2 drives and then partition that using LVM. Unfortunately partman complains when creating LVM volumes saying there no partitions in recipe that could be used with LVM (in console it complains about… >>> More
Restore data from overwritten LVM

as seen on Server Fault - Search for 'Server Fault'
I lost all of my data (8 TB) which I collected over the past few years yesterday because I made some seriuos mistakes during the remounting of my LVM. I run a XenServer5.6 installation with additional 4 harddisks for data storage. An LVM over those 4 HDDs was used to store all of my data. Yesterday… >>> More
how to multi-boot/upgrade linux from LVM-based partition

as seen on Super User - Search for 'Super User'
i currently have FC3 linux which installed itself on the hard disk using LVM partitioning, so it is basically all one big partition. i would like to try some other distributions and upgrade to something newer, but don't want to lose my current capabilities and data files, and i know nothing or less… >>> More

Related posts about mount

12.10 update breaks NFS mount

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've just upgraded to the latest 12.10 beta. Rebooted twice. The problem is with the NFS folders not mounting, here's a verbose log. # mount -v myserver:/nfs_shared/tools /tools/ mount: no type was given - I'll assume nfs because of the colon mount.nfs: timeout set for Mon Oct 1 11:42:28 2012 mount… >>> More
Mount SMB / AFP 13.10

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I cannot seem to get Ubuntu to mount a mac share via SMB or AFP. I've tried the following... AFP: apt-get install afpfs-ng-utils mount_afp afp://user:password@localip/share /mnt/share Error given: "Could not connect, never got a reponse to getstatus, Connection timed out". Which is odd as I can… >>> More
Mount Return Code for CIFS mount

as seen on Server Fault - Search for 'Server Fault'
When I run the following command (as root or via sudo) from a bash script I get an exit status (or return code in mount man page parlance) of 1: mount -v -t cifs //nasbox/volume /tmpdir/ --verbose -o credentials=/root/cifsid & /tmp/mylog It outputs the following into the myflog file: parsing… >>> More
Disable raid member check upon mount to mount damaged nvidia raid1 member

as seen on Server Fault - Search for 'Server Fault'
Hi, A friend of mine destroyed his Nvidia RAID1 array somehow and in trying to fix it, he ended up with a non-working array. Because of the RAID metadata, the actual disk data was stored at an offset from the beginning. I was able to identify this offset with dd and a hexeditor and then I used losetup… >>> More
Network shares do not mount.

as seen on Super User - Search for 'Super User'
My network shares were mounting fine yesterday.. suddenly they are not. They were mounting fine for the last two weeks or however long since I added them. When I run sudo mount -a I get the following error: topsy@monolyth:~$ sudo mount -a mount error(12): Cannot allocate memory Refer to the mount… >>> More