From mboxrd@z Thu Jan 1 00:00:00 1970 From: tirumalareddy marri Subject: Re: 64k Page size + ext3 errors Date: Mon, 28 Jul 2008 16:42:55 -0700 (PDT) Message-ID: <153154.27693.qm@web81301.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-raid-owner@vger.kernel.org To: Roger Heflin Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Roger, =A0=A0 I did sync after I copied the 128MB data. Isn't that should guar= antee data is flushed to disk ? I am using "sum" command to check if da= ta file is copied to Disk is valid or not.=20 Here=A0is 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 t= o 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 d= evice" 2. Copied 128MB and 385MB file. Checked check sum, they are matching ch= eck 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 d= evice" 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 ---- =46rom: Roger Heflin To: tirumalareddy marri Cc: linux-raid@vger.kernel.org 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 a= ny issue. As many of you know, we will get better performance when we s= tore bigger files like videos. >=A0=20 > 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 th= e following errors. Any clue what could be wrong.=20 >=A0=20 > Errors 1: > EXT3-fs error (device md0): ext3_new_block: Allocating block in syste= m zone - blocks from 65533, length 1 > EXT3-fs error (device md0): ext3_new_block: Allocating block in syste= m zone - blocks from 65534, length 1 >=A0=20 >=A0=20 > Errors2: > EXT3-fs error (device md0): ext3_readdir: bad entry in directory #2: = rec_len % 4 !=3D 0 - offset=3D0, inode=3D3040 >=20 All that error means is that something screwed up the filesystem stuff = when you=20 copied the large file. The lack of an error in the first case does not mean that the correct s= tuff was=20 written to the filesystem, just that nothing screwed up the internal fi= lesystem=20 data, or that the cache saved you. I would suggest setting up a simple test using no filesystem and all, a= nd make=20 sure that the correct data can be read and written (and a large enough = amount of=20 data that you are not reading out of cache) from the MD device directly= , write a=20 =A0 specific pattern that would have lots of unique data.=A0 If you don= 't do enough=20 data then things *WILL* be coming from cache and still could be screwed= up on=20 disk, and this may be what is going on in the case of the 128MB=A0 vs 1= =2E8GB case,=20 in both cases it may be wrong on disk, but with the 128MB case is comin= g from=20 cache, and in the 1.8GB case is coming off disk. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Rog= er -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at=A0 http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html