[Haifux] Journalized filesystem question

[Baruch Even]

Hai Zaar wrote:
> On Thu, Feb 21, 2008 at 5:42 PM, Aur Saraf <sonoflilit at gmail.com> wrote:
>>  "If power falls down and shuts off a box running a journalized
>>  filesystem, is it safe to continue using it without first running a
>>  disk integrity scan?
> Disk scan is done every boot, however on journalized file systems it
> usually just checks/replays/purges journal.

Disk scan is not done every boot, if the system left the filesystem
dirty the disk will be scanned. A journaled filesystem "scan" will
consist of replaying the journal, a non-journaled fs will undergo a full
fsck.

Some (all?) filesystems have a policy to do a disk scan every x reboots
or y days. Ext2 & 3 have that at least.

>> In other words, is there any time during the life
>>  of a disk running a journalized filesystem when the filesystem is
>>  practically corrupted?"

Theoretically this should only happen due to bugs and should be
extremely rare.

Baruch