On Thu, Nov 12, 2009 at 11:59:50AM -0200, Renato S. Yamane wrote: > Hi, > > [please, leave me on cc because I'm not subscribed on this ML] > > I'm using Intel SSD X25-M on my laptop, and I always hear that is not a > good idea use journal on SSD (it decrease the life time). > > I ask Intel about this, but I don't receive any answer. > > So, I would like to know if is possible disable Journal on EXT4. It is possible to create an ext4 file system without a journal. It would mean that unclean shutdowns would require a full fsck, which on a freshly created file system on an SSD isn't _that_ bad. Depending on how full/fragmented your filesystem happens to be, it will probably be under 10 seconds. That being said, though, it shouldn't be necessary to avoid using a journal on the Intel SSD. Intel says that laptop will last at least 5 years with 10GB worth of writes per day, and that's a huge amount. I have an X25-M SSD in my laptop, using an ext4 file system and with the journal enabled, and since the file system was created 266 days ago, when I put my X25-M into service, the drive has seen 570GB worth of writes, so I'm averaging 2.14 GB writes per day. That's well under the 20GB of writes/per day upon which Intel based its 5 year lifetime (and most hard drives, and heck, most laptops generally aren't in service for that long before they are replaced.) I have done a few things to reduce needless disk utilization, such as using tmpfs for /tmp and configuring firefox to place its cache in /tmp, but the bottom line is I wouldn't really worry that much about the journal. If you really want to run without a journal, you can use "mke2fs -t ext4 -O ^has_journal /dev/XXX" to format an ext4 filesystem without a journal. But there will be some distinct tradeoffs with omitting the journal, including possibility that sometimes on an unclean shutdown you will need to do a manual e2fsck pass. Best regards, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
