How to set the journal size? Don't see that as part of mkfs.lustre. Lin
> -----Original Message----- > From: Andreas Dilger [mailto:[EMAIL PROTECTED] > Sent: Monday, February 05, 2007 9:03 AM > To: Lin Shen (lshen) > Cc: [email protected] > Subject: Re: [Lustre-discuss] disk space needed to run MDS > > On Feb 02, 2007 10:25 -0800, Lin Shen (lshen) wrote: > > Could you explain a bit more how the number 400M was decided? Ext3 > > itself won't need that much disk space, right? Also, is this number > > related to the total capacity of the Luster filesystem? In other > > words, will the MDS always need 400M to work properly for a > filesystem > > of size 1T or just 1G? By switching to a different underline > > filesystem (i.e., from ext3 to ext2), can this number be lowered? > > In fact you do NOT need the full 400MB of journal space, and > lconf will not create a journal that large if you have a > smaller filesystem. > > The default size of the journal is: > - device size < 1GB => use default mke2fs, 16MB > - 1GB < device size < 10GB => use device size / 25 > - device size > 10GB => use 400MB > > > This is important to us. Since we may have a use case that > runs Luster > > on a 1G Compact Flash (to be shared among a few nodes). > Does this mean > > that only a little more than half of the capacity can be > used for data? > > No, nothing of the sort. Ext3 can have a journal as small as > 4MB, regardless of the device size. The only drawback is a > potential reduction in performance when there are many > clients. In a small setup like yours it may not make much > difference at all. > > > > -----Original Message----- > > > From: Andreas Dilger [mailto:[EMAIL PROTECTED] > > > Sent: Monday, January 29, 2007 7:04 PM > > > To: Lin Shen (lshen) > > > Cc: [email protected] > > > Subject: Re: [Lustre-discuss] disk space needed to run MDS > > > > > > On Jan 29, 2007 12:25 -0800, Lin Shen (lshen) wrote: > > > > I read once in the alias that running MDS requires a > minimum disk > > > > space of 400MB + 4kB * number of files. Is this still the > > > case with 1.6beta? > > > > > > Yes. This relates more to ext3 than to Lustre. > > > > > > Cheers, Andreas > > > -- > > > Andreas Dilger > > > Principal Software Engineer > > > Cluster File Systems, Inc. > > > > > Cheers, Andreas > -- > Andreas Dilger > Principal Software Engineer > Cluster File Systems, Inc. > _______________________________________________ Lustre-discuss mailing list [email protected] https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
