dean gaudet wrote: > On Sun, 17 Jun 2007, Wakko Warner wrote: > > > > i use an external write-intent bitmap on a raid1 to avoid this... you > > > could use internal bitmap but that slows down i/o too much for my tastes. > > > i also use an external xfs journal for the same reason. 2 disk raid1 for > > > root/journal/bitmap, N disk raid5 for bulk storage. no spindles in > > > common. > > > > I must remember this if I have to rebuild the array. Although I'm > > considering moving to a hardware raid solution when I upgrade my storage. > > you can do it without a rebuild -- that's in fact how i did it the first > time. > > to add an external bitmap: > > mdadm --grow --bitmap /bitmapfile /dev/mdX > > plus add "bitmap=/bitmapfile" to mdadm.conf... as in: > > ARRAY /dev/md4 bitmap=/bitmap.md4 UUID=dbc3be0b:b5853930:a02e038c:13ba8cdc I used evms to setup mine. I have used mdadm in the past. I use lvm ontop of it which evms makes it a little easier to maintain. I have 3 arrays total (only the raid5 was configured by evms, the other 2 raid1s were done by hand) > you can also easily move an ext3 journal to an external journal with > tune2fs (see man page). I only have 2 ext3 file systems (One of which is mounted R/O since it's full), all my others are reiserfs (v3). What benefit would I gain by using an external journel and how big would it need to be? > if you use XFS it's a bit more of a challenge to convert from internal to > external, but see this thread: I specifically didn't use XFS (or JFS) since neither one at the time could be shrinked. -- Lab tests show that use of micro$oft causes cancer in lab animals Got Gas??? - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
