From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Clements Subject: Re: Any way to Increase MD_SB_DISKS=27 ? I need 31 devices Date: Tue, 03 May 2005 10:03:55 -0400 Message-ID: <427784CB.7070000@steeleye.com> References: <427583FA.7030704@dtbb.net> <42764014.5060909@steeleye.com> <42775EF9.7030009@dtbb.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <42775EF9.7030009@dtbb.net> Sender: linux-raid-owner@vger.kernel.org To: Tyler Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Tyler wrote: > Isn't the superblock still limited to 27 drives though? .. is there The version 0.90 superblock is limited to 27 drives. Version 1 superblock is limited to about 2000 drives, because Neil shrunk the amount of per-drive data stored in the superblock drastically. The check in mdadm, is in the file mdadm.c, just grep for the message that you got ("invalid number of raid devices"). Comment out that code and recompile mdadm. Everything should work after that. The kernel you have already has support for version 1 superblocks. -- Paul > maybe a patch for version 1 superblocks that i don't have in > 2.6.12-rc3-mm2, that changes the max drives in the md_p.h and md.c > driver? There is only 4096 bytes earmarked for superblocks, and within > that amount, there isn't enough room to list more than 27 drives that > may be part of the same array. > > Do I need some more patches for this to work, that aren't in the -mm > tree yet? I was under the impression (from the mdadm v2.0 announce > file, that anything *after* 2.6.11-rc3 in the -mm tree would have the > required patches. > > Also, where can I disable the check in mdadm? > > Thanks, > Tyler. > > Paul Clements wrote: > >> Tyler wrote: >> >>> PS - I've tryed the latest 2.6.12-rc3-mm2 kernel, with mdadm >>> v2.0-devel, using the --metadata 1.0 option on the create line, and >>> still get: >> >> >> >>> # mdadm -C -e 1.0 -l 6 -n 31 /dev/md0 /dev/hdb /dev/hdc /dev/hdd >>> /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg >>> /dev/sdh /dev/sdi /dev/sdj /dev/sdk /dev/sdl /dev/sdm /dev/sdn >>> /dev/sdo /dev/sdp /dev/sdq /dev/sdr /dev/sds /dev/sdt /dev/sdu >>> /dev/sdv /dev/sdw /dev/sdx /dev/sdy /dev/sdz /dev/sdaa /dev/sdab >>> mdadm: invalid number of raid devices: 31 >> >> >> >> As far as I can tell, mdadm just shouldn't give this error when you're >> using a version 1 superblock. If you disable that check in mdadm.c, I >> think everything will work. Version 1 superblocks allow something like >> 2000 disks in an array. >> >> -- >> Paul > > > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >