attaching my last two responses to the mailing list as I forgot to include it on CC's. On Sun, May 30, 2010 at 4:51 PM, Keith . <lukano@xxxxxxxxx> wrote: > and for posterity, adding relevant syslog entries. The capacity > change noted towards the end may be the root of the problem, due to > the steps I took to reach where I am - as mentioned in my previous > email. > > [ 3132.556397] md: raid5 personality registered for level 5 > [ 3132.556399] md: raid4 personality registered for level 4 > [ 3132.556557] raid5: device sdc1 operational as raid disk 0 > [ 3132.556560] raid5: device sdd1 operational as raid disk 5 > [ 3132.556563] raid5: device sde1 operational as raid disk 4 > [ 3132.556566] raid5: device sdf1 operational as raid disk 2 > [ 3132.556568] raid5: device sdb1 operational as raid disk 1 > [ 3132.557254] raid5: allocated 6386kB for md127 > [ 3132.557301] 0: w=1 pa=0 pr=6 m=1 a=2 r=6 op1=0 op2=0 > [ 3132.557305] 5: w=2 pa=0 pr=6 m=1 a=2 r=6 op1=0 op2=0 > [ 3132.557308] 4: w=3 pa=0 pr=6 m=1 a=2 r=6 op1=0 op2=0 > [ 3132.557311] 2: w=4 pa=0 pr=6 m=1 a=2 r=6 op1=0 op2=0 > [ 3132.557315] 1: w=5 pa=0 pr=6 m=1 a=2 r=6 op1=0 op2=0 > [ 3132.557318] raid5: raid level 5 set md127 active with 5 out of 6 > devices, algorithm 2 > [ 3132.557321] RAID5 conf printout: > [ 3132.557323] --- rd:6 wd:5 > [ 3132.557326] disk 0, o:1, dev:sdc1 > [ 3132.557328] disk 1, o:1, dev:sdb1 > [ 3132.557331] disk 2, o:1, dev:sdf1 > [ 3132.557333] disk 4, o:1, dev:sde1 > [ 3132.557336] disk 5, o:1, dev:sdd1 > [ 3132.557377] md127: detected capacity change from 0 to 7501495992320 > [ 3132.557590] md127: unknown partition table > [187074.092745] REISERFS (device dm-0): found reiserfs format "3.6" > with standard journal > [187074.092796] REISERFS (device dm-0): using ordered data mode > [187074.120739] REISERFS (device dm-0): journal params: device dm-0, > size 8192, journal first block 18, max trans len 1024, max batch 900, > max commit age 30, max trans age 30 > [187074.121360] REISERFS (device dm-0): checking transaction log (dm-0) > [187074.322428] REISERFS (device dm-0): Using r5 hash to sort names > [360791.852592] md127: detected capacity change from 7501495992320 to > 6001010237440 > [360829.233219] md127: unknown partition table > > > On Sun, May 30, 2010 at 4:46 PM, Keith . <lukano@xxxxxxxxx> wrote: >> Sorry for the late followup on this. >> >> I am still struggling with the shrink, the following is not giving me >> any useable results for array-size suggestion from mdadm. >> >> mdadm -v --grow /dev/md127 --array-size= does not give me any error or >> results, nor a syslog entry with the array-size value. >> >> I'm wondering if the complications I'm seeing are related to my >> situation. I'm going to reiterate it again, as I don't think I was >> clear originally; >> >> - I had a 6 disk RAID6 array (1.5tb disks). >> - One of the drive failed, and due to my poor luck with 1.5's - I >> decided to 'shrink it from a degraded RAID6 array (running 5 of 6 >> disks) to a stable and undegraded RAID5. >> - I was able to convert it from RAID6 to RAID5, and am now left with a >> degraded RAID5 array (6 disks, 5 active). >> - The actual available space should not change, as in the end there 4x >> drives + the one parity for RAID5. >> >> Correct? Am I complicating things somewhere, or forgetting some vital logic? >> >> And as requested, /proc/mdstat is as follows; >> >> Personalities : [raid6] [raid5] [raid4] >> md127 : active raid5 sdc1[0] sdd1[5] sde1[4] sdf1[2] sdb1[1] >> 5860361560 blocks level 5, 64k chunk, algorithm 2 [6/5] [UUU_UU] >> >> Thanks again for your help Neil. >> >> - Keith >> >> >> On Thu, May 20, 2010 at 4:32 PM, Neil Brown <neilb@xxxxxxx> wrote: >>> On Thu, 20 May 2010 15:42:23 -0600 >>> "Keith ." <lukano@xxxxxxxxx> wrote: >>> >>>> Thanks for the quick reply Neil, >>>> >>>> I tried the suggested syntax, excluding the array-size in order to >>>> have mdadm give me the value - but it did not. I also tried grabbing >>>> the current array size from df, but I got an error about being unable >>>> to change array size in the same operation. >>>> >>>> So just to confirm I'm understanding you correctly ; mdadm -G >>>> /dev/md127 --raid-devices 5 --backup=/root/backup - should generate >>>> an error that provides the array-size value? >>> >>> Yes. >>> Actually, you do probably need to change the size first: >>> >>> mdadm --grow /dev/md127 --array-size=xxxxx >>> then once you are sure you haven't lost you data, change the number of >>> devices. >>> >>> It might help if you ran the commands with "-v" and reported all the >>> messages generated, and any kernel log messages. >>> And maybe >>> cat /proc/mdstat >>> >>> just to give us some more context.. >>> Maybe you have a write-intent-bitmap attached to the array. You cannot >>> reshape an array with one of those attached. >>> >>> NeilBron >>> >>> >>>> >>>> On Thu, May 20, 2010 at 3:34 PM, Neil Brown <neilb@xxxxxxx> wrote: >>>> > On Thu, 20 May 2010 07:45:23 -0600 >>>> > "Keith ." <lukano@xxxxxxxxx> wrote: >>>> > >>>> >> Does mdadm 3.1.x not support shrinking the number of disks in a RAID5 array? >>>> >> >>>> >> I have successfully converted my 6x1.5tb RAID6 array to a 6x1.5tb >>>> >> RAID5 array. The issue that I now face is that one of those 6 drives >>>> >> is failed / removed, and as a result - the new RAID5 array is down >>>> >> it's parity drive. >>>> >> >>>> >> I knew I was short a disk when I started the process, but I was under >>>> >> the assumption that mdadm now supported shrinking of RAID5/6 arrays. >>>> >> Am I mistaken, or can anyone throw some suggestions at me so I can >>>> >> give it a try? >>>> > >>>> > It should work. >>>> > >>>> > mdadm -G /dev/mdX --raid-devices 5 --array-size=XXXXX >>>> > --backup=/root/backup-file >>>> > >>>> > If you don't give the 'array-size' value mdadm will tell you what it has to >>>> > be. You need to be sure that all your data is already within that space. >>>> > >>>> > NeilBrown >>>> > >>> >>> >> > -- 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
