{"id":131,"date":"2009-11-07T00:43:23","date_gmt":"2009-11-07T00:43:23","guid":{"rendered":"http:\/\/www.thowden.com.au\/?p=131"},"modified":"2009-11-07T00:43:23","modified_gmt":"2009-11-07T00:43:23","slug":"adding-new-drives-to-smeserver-as-a-raid-pair","status":"publish","type":"post","link":"https:\/\/howden.net.au\/thowden\/2009\/11\/adding-new-drives-to-smeserver-as-a-raid-pair\/","title":{"rendered":"Adding new drives to SMEServer as a raid pair"},"content":{"rendered":"

Adding two new 1Tbyte drives into my SMEServer v7.4 as a raid pair for backups. Made good use of the LVM How-To<\/a> (again!)<\/p>\n

Obviously installing the physical drives comes first and they should be recognised by the bios and then as the server booted mine were flagged as \/dev\/sda and sdb respectively.<\/p>\n

Because these are new drives and I am adding them rather than modding the current drives I am working in the normal console.<\/p>\n

#fdisk \/dev\/sda
\n>p –print the current state (should show as blank)
\n>n –add a new partition
\n>p –primary partition
\n>1 –partition number
\n>t –change the type or id of the drive
\n>hex=\u00a0fd –change to Linux raid
\n>p –print again the details and shows now as approx 1T lvm partition
\n>w –write the partition table and exit<\/p><\/blockquote>\n

repeat for \/dev\/sdb<\/p>\n

#shutdown -r now<\/p><\/blockquote>\n

Restarting the server should automatically match the two drives as a raid pair.\u00a0 Check by reading through<\/p>\n

#cat \/var\/log\/dmesg<\/p><\/blockquote>\n

for something like this:<\/p>\n

md: Autodetecting RAID arrays.
\nmd: could not bd_claim hda1.
\nmd: could not bd_claim hda2.
\nmd: could not bd_claim hdb1.
\nmd: could not bd_claim hdb2.
\nmd: autorun …
\nmd: considering sdb1 …
\nmd:\u00a0 adding sdb1 …
\nmd:\u00a0 adding sda1 …
\nmd: created md3
\nmd: bind
\nmd: bind
\nmd: running:
\nraid1: raid set md3 active with 2 out of 2 mirrors
\nmd: … autorun DONE.<\/p><\/blockquote>\n

Next check what is showing for LVM<\/p>\n

#pvscan<\/p>\n

PV \/dev\/md2\u00a0\u00a0 VG main\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 lvm2 [186.19 GB \/ 64.00 MB free]
\nPV \/dev\/md3\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 lvm2 [931.51 GB]
\nTotal: 2 [1.09 TB] \/ in use: 1 [186.19 GB] \/ in no VG: 1 [931.51 GB]<\/p><\/blockquote>\n

shows my new pair ready for inclusion in the LVM volume groups and logical volume.<\/p>\n

Here I ran into an annoyance with a message Insufficient Extents.<\/p>\n

I figure I want the whole disk and the above indicates 931.51G is free<\/p>\n

lvm> lvcreate \/dev\/backups -L931.51G -n backups
\n\u00a0 CTRL-c detected: giving up waiting for lock
\n\u00a0 Rounding up size to full physical extent 931.51 GB
\n\u00a0 Insufficient free extents (238466) in volume group backups: 238467 required<\/p><\/blockquote>\n

I have since learnt that lvm\u00a0does some rounding\u00a0and that using the ‘byte’ size is not the best option.<\/p>\n

vgdisplay
\n\u00a0 — Volume group —
\n\u00a0 VG Name\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 backups
\n\u00a0 System ID
\n\u00a0 Format\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 lvm2
\n\u00a0 Metadata Areas\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1
\n\u00a0 Metadata Sequence No\u00a0 8
\n\u00a0 VG Access\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 read\/write
\n\u00a0 VG Status\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 resizable
\n\u00a0 MAX LV\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\n\u00a0 Cur LV\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\n\u00a0 Open LV\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\n\u00a0 Max PV\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0
\n\u00a0 Cur PV\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1
\n\u00a0 Act PV\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1
\n\u00a0 VG Size\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 931.51 GB
\n\u00a0 PE Size\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 4.00 MB
\n\u00a0 Total PE\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 238466
\n\u00a0 Alloc PE \/ Size\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0 \/ 0
\n\u00a0 Free\u00a0 PE \/ Size\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 238466 \/ 931.51 GB
\n\u00a0 VG UUID\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 #######################<\/p><\/blockquote>\n

In the above screen the important bit is the “Total PE\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 238466” which tells me the Physical Extents available.<\/p>\n

Changing my command to create the lv so that I use the PE rather than byte value<\/p>\n

lvm> lvcreate \/dev\/backups -l238466 -n backups
\n\u00a0 Logical volume “backups” created
\nlvm><\/p><\/blockquote>\n

gives a successful outcome.<\/p>\n

lvm> lvscan
\n\u00a0 ACTIVE\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ‘\/dev\/main\/root’ [184.19 GB] inherit
\n\u00a0 ACTIVE\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ‘\/dev\/main\/swap’ [1.94 GB] inherit
\n\u00a0 ACTIVE\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ‘\/dev\/backups\/backups’ [931.51 GB] inherit\u00a0<\/p><\/blockquote>\n

Next to format the new backups volume<\/p>\n

#mke2fs \/dev\/backups\/backups<\/p><\/blockquote>\n

Add the journalling<\/p>\n

#tune2fs -j \/dev\/backups\/backups<\/p><\/blockquote>\n

Edit fstab to add the mounting of this drive by inserting this line<\/p>\n

\/dev\/backups\/backups \/backups ext3 usrquota,grpquota 1 1<\/p><\/blockquote>\n

and create the mount point – in my case – \/backups<\/p>\n

#mkdir \/backups<\/p><\/blockquote>\n

Then one final restart of the server to see that it all starts ok and its done.<\/p>\n","protected":false},"excerpt":{"rendered":"

Installing new drives as a raid pair using LVM into an SMEServer v7.4 based on CentOS4.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[88],"class_list":["post-131","post","type-post","status-publish","format-standard","hentry","category-hardware-configuration","tag-smeserver-linux-hard-disk-drive-installation"],"_links":{"self":[{"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/posts\/131","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/comments?post=131"}],"version-history":[{"count":0,"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/posts\/131\/revisions"}],"wp:attachment":[{"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/media?parent=131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/categories?post=131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/howden.net.au\/thowden\/wp-json\/wp\/v2\/tags?post=131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}