BenV's notes

Tag: mdadm

Linux Software Raid disk upgrades

by on Dec.16, 2012, under Software

Every now and then you find out that this huge disk you’ve been using — you know, the one that when you bought it you thought “How on earth am I ever going to fill this one up? My biggest game can fit on this disk 100 times!” — … isn’t as huge anymore. Or at least all the free space on it has disappeared and nagios is whining that your disk is full or about to explode.
Some background info: My fileserver here at home has 3 linux software raid arrays (raid-1 mirrors) on top of 4 physical disks. The first and also smallest array is used as root filesystem to boot from into Slackware linux. The second and third arrays are both big and simply for storage of games, music, series, etc.
When I created that first array a few years ago I figured “Hm, 20GB should be enough for a slackware install, right? Well, let’s just make it 50GB to be sure, we have plenty of space anyway on this huge disk“. Back then the ‘huge’ disks were 500GB. Meanwhile those 500GBs have been replaced with 1TB ones, but that array remained the same. Today I have a set of 1.5TB drives to replace the 1TB ones. Not a huge upgrade, but I didn’t have to buy these disks since they came from a server that had its drives upgraded as well. Anyhow, the 50GB partition managed to get filled with over 40GB of stuff that I can’t trash (mostly user home directories). I could move them to a different partition of course, but today we’re going to resize that partition to 100GB and put the rest in the storage partition.
Off-topic note: Do you also hate it when you’re typing in a browser and hit CRTL-w to delete your last word and realize you just closed your tab? I sure as heck do, good thing wordpress saves these drafts every now and then 🙂 (continue reading…)

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Slackware64-current and udev 1.82

by on Jul.24, 2012, under Software

Some days after tinkering for a little bit you come to the realization that it might be better to stop doing anything with devices and just wait for the day to pass, because everything you touch breaks in the most spectacular ways. Of course this never stopped me from breaking even more, but I’m stupid like that.
Today is a day like that it seems. First our ADSL line at home received an upgrade to FTTH (aka a fiber connection), boosting our internet speed from a lousy 8Mbit down to 50Mbit down, and from less than 1Mbit upstream to 50Mbit upstream. (continue reading…)

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Linux Software Raid-1 issue

by on Jan.29, 2011, under Software

It just took me about an hour to figure this one out, so here’s the story for the next time I run into it.
Steps taken:
* New machine
* 2 harddisks (Western Digital Greens, so used wdidle3 on them!)
* Boot Slackware64 installer from PXE/NFS
* cfdisk, create 2 identical partitions, make bootable, set type to FD, write, quit
* mdadm –create /dev/md0 –raid-level=1 –raid-devices=2 /dev/sda1 /dev/sdb2
* install slackware64, grub2 and some other junk
* reboot

Sounds good right?
Well, for some reason the array kept booting up with only 1 of 2 disks active.
No errors or warnings, just kept fucking up. /proc/mdstat looked like

# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md0 : active raid1 sdb1[1]
39061952 blocks [1/2] [_U]

Adding /dev/sda1 back (mdadm /dev/md0 –add /dev/sda1) worked fine too, the array resync-ed without problems.

After about an hour of trying to recreate superblocks and that sort of stuff I found it:
The partition type of /dev/sda1 was set to 0x83 instead of 0xFD.
Thanks cfdisk, last time I used that piece of garbage. (I’m 100% certain I set them to 0xFD, but somehow it’s bugging for me lately in cfdisk).

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