Hi Roger, I did sync after I copied the 128MB data. Isn't that should guarantee data is flushed to disk ? I am using "sum" command to check if data file is copied to Disk is valid or not. Here is more information. setup: Created /dev/md0 of 30GB size , created ext3 files system. Then started SAMBA server to export mountded /dev/md0 to a windows machine to run IO and copy files. 4K Page size: ------------------- 1. IO Meter Test: Works just fine. 2. Copied 1.8 GB file and check sum is good. 3. Performance is not good because of small page size. 16k Page size: --------------------- 1. RAID-5 fails some times with " Attempt to access beyond the end of device" 2. Copied 128MB and 385MB file. Checked check sum, they are matching check sum. 3. Copied 1.8 GB file , this failed checksum test using "sum" command. I see "EXT3-fs errors". 64K Page size: ---------------------- 1. RAID-5 failes some times with "Attempt to access beyond the end of device" 2. Able to copy 128MB data and check sum test passed. 3. Copying 385MB and 1.8 GB file with EXT3-fs errors. Thanks, Marri ----- Original Message ---- From: Roger Heflin <rogerheflin@xxxxxxxxx> To: tirumalareddy marri <tirumalareddymarri@xxxxxxxxx> Cc: linux-raid@xxxxxxxxxxxxxxx Sent: Sunday, July 27, 2008 7:10:07 PM Subject: Re: 64k Page size + ext3 errors 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 -- 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 -- 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
