Jakob �stergaard wrote:
> SW RAID is beautiful for a handfull or three of disks, but when you're working
> with hundreds of disks the administrative costs of not-so-flexible-if-any
> hotswap is a killer. I still maintain that it would be interesting to see
> software RAID-0 on this size of systems though, as hotswap usually doesn't
> matter so much on RAID-0 anyway. That will be a 2.4 task though, as the
> SW RAID in 2.2 is not able to handle this number of disks.
>
> It would be nice if a program such as ASCI could put the resources needed
> into Linux to actually get decent hot swap capability... Let's see what
> happens.
>
FYI - there is a hotswappable, software raid system available for Linux.
It's from raidzone. Some sample numbers using one of their smart racks,
with 15 5400 IBM 37gb IDE drives in it.
System information:
Dual Intel PIII/450
256 mb of ram
channel bond with 2x100mb FastEthernets
15 ea, IBM 37gb, UltraDMA, 5400 IDE drives (hotswappable!)
One raidzone 15drive rack
Redhat 6.1
Linux 2.2.13 w/NFS, TLBIPI, serial-sysrq, channel bonding patches
System is used for NFS serving of a 500gb file system, to 68 systems.
This is a 15way software raid5 array, with 4kb blocks size in the
filesystem.
[root@pdsfdv09 data]# /auto/work/bench/bonnie/bonnie -s 1024
File './Bonnie.2899', size: 1073741824
Writing with putc()...done
Rewriting...done
Writing intelligently...done
Reading with getc()...done
Reading intelligently...done
Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
-------Sequential Output-------- ---Sequential Input--
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
1024 14172 88.7 19460 26.6 12208 36.7 21241 85.0 58386 57.7
319.8 6.5
[root@pdsfdv09 tiotest-0.16]# ./tiobench.pl --dir /export/data
Found memory size of 255.94140625 MB
Now running ./tiotest -t 1 -f 510 -s 4000 -b 4096 -d /export/data -T -W
Size is MB, BlkSz is Bytes, Read and Write are MB/sec, Seeks are
Seeks/sec
Machine Directory Size(MB) BlkSz Threads Read Write
Seeks
----------- ----------- --------- ------- --------- ------ -------
-------
/export/dat 510 4096 1 60.284 16.569
226.116
Now running ./tiotest -t 2 -f 255 -s 2000 -b 4096 -d /export/data -T -W
/export/dat 510 4096 2 59.649 16.336
391.773
Now running ./tiotest -t 4 -f 127 -s 1000 -b 4096 -d /export/data -T -W
/export/dat 510 4096 4 61.800 16.574
649.351
Now running ./tiotest -t 8 -f 63 -s 500 -b 4096 -d /export/data -T -W
/export/dat 510 4096 8 60.359 16.169
1136.36
[root@pdsfdv09 tiotest-0.16]# ./tiobench.pl --dir /export/data --block
8192
Found memory size of 255.94140625 MB
Now running ./tiotest -t 1 -f 510 -s 4000 -b 8192 -d /export/data -T -W
Size is MB, BlkSz is Bytes, Read and Write are MB/sec, Seeks are
Seeks/sec
Machine Directory Size(MB) BlkSz Threads Read Write
Seeks
----------- ----------- --------- ------- --------- ------ -------
-------
/export/dat 510 8192 1 57.823 16.661
208.768
Now running ./tiotest -t 2 -f 255 -s 2000 -b 8192 -d /export/data -T -W
/export/dat 510 8192 2 61.298 16.201
351.803
Now running ./tiotest -t 4 -f 127 -s 1000 -b 8192 -d /export/data -T -W
/export/dat 510 8192 4 62.331 16.392
637.959
Now running ./tiotest -t 8 -f 63 -s 500 -b 8192 -d /export/data -T -W
/export/dat 510 8192 8 56.949 16.385
1049.86
--
------------------------+--------------------------------------------------
Thomas Davis | PDSF Project Leader
[EMAIL PROTECTED] |
(510) 486-4524 | "Only a petabyte of data this year?"
