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Software RAID/Filesystem problems?

DISCUSSION [email protected] 1 participant 1 message May 29, 2002

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Hello,

I have run into a problem with software raid with large filesystems. I am not sure if this is a software raid limitation or a filesystem limitation. I currently have two 3ware raid controllers that have 1.1TB (yes, terrabyte) of space on each. I want to stripe the two hardware raid controllers using software raid but when I try to make the raid using the command mkraid /dev/md0 it pukes out this:

DESTROYING the contents of /dev/md0 in 5 seconds, Ctrl-C if unsure! handling MD device /dev/md0
analyzing super-block

disk 0: /dev/sdb1, 1120597978kB, raid superblock at 1120597888kB
disk 1: /dev/sdc1, 1120597978kB, raid superblock at 1120597888kB
raid0: looking at sdb1
raid0:   comparing sdb1(1120597888) with sdb1(1120597888)
raid0:   END
raid0:   ==> UNIQUE
raid0: 1 zones
raid0: looking at sdc1
raid0:   comparing sdc1(1120597888) with sdb1(1120597888)
raid0:   EQUAL
raid0: FINAL 1 zones
raid0: zone 0
raid0: checking sdb1 ... contained as device 0

(1120597888) is smallest!.
raid0: checking sdc1 ... contained as device 1
raid0: zone->nb_dev: 2, size: -2053771520
raid0: current zone offset: 1120597888
raid0: done.
raid0 : md_size is -2053771520 blocks. raid0 : conf->smallest->size is -2053771520 blocks. raid0 : nb_zone is 1.
raid0 : Allocating 8 bytes for hash.

Notice the huge negative numbers -2053771520. I have tried this with a couple different block sizes but it doesn't help. When I build a filesystem on it, in this case I am trying reiserfs, it builds it but in the message log I have these errors:

09:00: rw=0, want=134217729, limit=-2053771520
attempt to access beyond end of device
09:00: rw=0, want=134217730, limit=-2053771520
attempt to access beyond end of device
09:00: rw=0, want=134217731, limit=-2053771520
attempt to access beyond end of device

There are quite a few, I didn't post them all. Then when I mount the fs it only reports it as about a 93GB filesystem instead of the 2.2TB it should be. I did this same configuration in RAID 1(mirror) and it all worked well, no errors and the reported filesystem size was correct. So I guess my question
is: Am I hitting a kernel limit here or a filesystem limit, or is this just a plain ol bug? What is the current maximum filesystem size? I need to I can try ext3 but it always takes a bit to format. This is on RedHat 7.3 with the stock 2.4.18-4smp kernel. I also tried it with the standard 2.4.18 kernel with
the same results. Any suggestions/information would be appreciated. Let
me know if any more info would help, I usually forget info that is important.

Here is a copy of my /etc/raidtab (currently set up for mirroring, not stripping)

raiddev /dev/md0
raid-level 1
nr-raid-disks 2
persistent-superblock 1
chunk-size 4
device /dev/sdb1
raid-disk 0
device /dev/sdc1
raid-disk 1

Thanks,
Steven