On 2009-03-09_09:20:06, Steven Demetrius wrote: > Paul E Condon wrote: >> On 2009-03-08_13:41:53, Lists wrote: >>> Steven Demetrius wrote: >>>> Paul E Condon wrote: >>>>> I'd like some confirmation, or refutation, of some reasoning: >>>>> >>>>> I have a USB external hard drive. It came with vfat fs, but I want to >>>>> write an ext2/3 fs on it. All my internal HD are ext3, but should this >>>>> one be ext3, also? Doesn't ext3 essentially write everything twice, >>>>> first to the journal, and then to the actual target location? This is >>>>> OK with an internal bus interface from the CPU to the HD, but USB is >>>>> not so fast. So I think I should not use ext3 for this HD. Is this >>>>> correct? >>>>> >>>>> TIA >>>> Basically ext3 is ext2 with Journaling. Journaling basically >>>> safe-guards against power failure and system crashes. It is well >>>> suited for system partitions and partitions that are being used >>>> most of the time your computer is on. >>>> >>>> Journaling uses significantly more disk space and does not allow for >>>> deleted file recovery. IT uses more resources that ext2. Journaling >>>> does not write everything twice. It keeps track of the file system >>>> which makes recovery fast and more reliable than file systems >>>> without Journaling. >>>> >>>> I recommend the following: >>>> >>>> ext3 - for system partitions and data partitions which are in use >>>> most of the time (/, /home, /var, etc. if they are separate >>>> partitions or drives). >>>> >>>> ext2 - for backup, removable, partitions rarely used, etc. >>>> >>>> If your USB external is for backup or file transfers then I >>>> recommend using the ext2 file system on it. Logic being that if >>>> your USB external data gets corrupted then you still have a copy of >>>> the data on another partition. >>>> >>>> FYI: >>>> Some people confuse backup with archiving. They will make copies of >>>> their data and store it away until they have data problems with the >>>> system. This is archiving. >>>> Backup is a never ending routine whether done once a week or one a >>>> month and also include regular data integrity checks of the backups. >>>> >>>> >>> Correction: >>> Journaling file system does write data twice. >>> ttp://en.wikipedia.org/wiki/Ext3 >> >> This is an interesting reference. I think I am convinced that journaling >> in Linux is -not- a finished story. >> >> Thanks for pointing it out. >> > > Paul: > > Did you take a look at the ext4 file system? > > Looking very interesting. Especially deframentation.
I read the description in wikipedia. We will all be doing ext4 in near future, I think. But for now, my project is making an archive of my check points. For this application I think ext2 provides a tiny decrease in overhead, for an infinitessimal increase in unreliability. For this app., there is always the option of a total re-run of any single job. Other issues like USB 2.0 vs USB 1.1 loom -much- larger. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
