Comments on: Size Can Matter: Ramdisk Journal Metadata Performance – Part 2 http://www.linux-mag.com/id/7675/ Open Source, Open Standards Sat, 05 Oct 2013 13:48:18 +0000 hourly 1 http://wordpress.org/?v=3.1 By: djekels http://www.linux-mag.com/id/7675/#comment-7713 djekels Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7675/#comment-7713 <p>I tried creating ram drives on a 3TB ext4 File System.</p> <p>pvcreate /dev/ram[0-20]<br /> vgcreate jrnlvg /dev/ram[0-20]<br /> lvcreate -L1G -n lv0 jrnlvg</p> <p>mkfs -O journal_dev /dev/jrnlvg/lv0<br /> tune2fs -L /opt journal device /dev/jrnlvg/lv0</p> <p>tune2fs -j -J device=/dev/jrnlvg/lv0 /dev/myTBvg/lv10</p> <p>this all works great</p> <p>the problem is when the system reboots, you must go through the whole process and 1+TB file systems regenerating their journals takes forever.</p> <p>Q: how can I dd or copy the ram device data to a regular disk.<br /> so when the system reboot, you setup the ram devices then copy the old jourabck before you fire up the FS? </p> I tried creating ram drives on a 3TB ext4 File System.

pvcreate /dev/ram[0-20]
vgcreate jrnlvg /dev/ram[0-20]
lvcreate -L1G -n lv0 jrnlvg

mkfs -O journal_dev /dev/jrnlvg/lv0
tune2fs -L /opt journal device /dev/jrnlvg/lv0

tune2fs -j -J device=/dev/jrnlvg/lv0 /dev/myTBvg/lv10

this all works great

the problem is when the system reboots, you must go through the whole process and 1+TB file systems regenerating their journals takes forever.

Q: how can I dd or copy the ram device data to a regular disk.
so when the system reboot, you setup the ram devices then copy the old jourabck before you fire up the FS?

]]>