From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Heflin Subject: Re: 64k Page size + ext3 errors Date: Sun, 27 Jul 2008 21:10:07 -0500 Message-ID: <488D2A7F.9080902@gmail.com> References: <576234.24141.qm@web81307.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <576234.24141.qm@web81307.mail.mud.yahoo.com> Sender: linux-raid-owner@vger.kernel.org To: tirumalareddy marri Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids tirumalareddy marri wrote: > I am using HW accelerated XOR engine for RAID-5 . I am seeing EXT3-fs errors when I use 64K page size. When I use 4K page size I don't see any issue. As many of you know, we will get better performance when we store bigger files like videos. > > When I copy 128MB size files using 64k page size no issues seen. When I tried to copy 1.8 GB file with 64KB page size support I am seeing the following errors. Any clue what could be wrong. > > Errors 1: > EXT3-fs error (device md0): ext3_new_block: Allocating block in system zone - blocks from 65533, length 1 > EXT3-fs error (device md0): ext3_new_block: Allocating block in system zone - blocks from 65534, length 1 > > > Errors2: > EXT3-fs error (device md0): ext3_readdir: bad entry in directory #2: rec_len % 4 != 0 - offset=0, inode=3040 > All that error means is that something screwed up the filesystem stuff when you copied the large file. The lack of an error in the first case does not mean that the correct stuff was written to the filesystem, just that nothing screwed up the internal filesystem data, or that the cache saved you. I would suggest setting up a simple test using no filesystem and all, and make sure that the correct data can be read and written (and a large enough amount of data that you are not reading out of cache) from the MD device directly, write a specific pattern that would have lots of unique data. If you don't do enough data then things *WILL* be coming from cache and still could be screwed up on disk, and this may be what is going on in the case of the 128MB vs 1.8GB case, in both cases it may be wrong on disk, but with the 128MB case is coming from cache, and in the 1.8GB case is coming off disk. Roger