Date: Thu, 7 Feb 2013 17:42:30 +0000 From: "Teske, Devin" <Devin.Teske@fisglobal.com> To: Paul Schmehl <pschmehl_lists@tx.rr.com>, "'FreeBSD Questions List'" <freebsd-questions@freebsd.org> Cc: "dteske@freebsd.org" <dteske@freebsd.org> Subject: RE: How to add unused space to an existing install Message-ID: <13CA24D6AB415D428143D44749F57D7201EA5CDF@ltcfiswmsgmb21> In-Reply-To: <6C52D891D96E0ACEBF1531DD@utd71538.campus.ad.utdallas.edu> References: <6C52D891D96E0ACEBF1531DD@utd71538.campus.ad.utdallas.edu>
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On 7 Feb 2013, Paul Schmehl wrote:
>=20
> --On February 6, 2013 5:21:39 PM -0600 dteske@freebsd.org wrote:
>=20
> >
> >
> >> -----Original Message-----
> >> From: owner-freebsd-questions@freebsd.org [mailto:owner-freebsd-
> >> questions@freebsd.org] On Behalf Of Paul Schmehl
> >> Sent: Wednesday, February 06, 2013 9:59 AM
> >> To: FreeBSD Questions List
> >> Subject: How to add unused space to an existing install
> >>
> >> I have a FreeBSD 8.3 RELEASE box that we recently discovered only has
> >> part of the "disk" being used. This box has four 1TB drives in RAID 5,
> >> and df only shows 500MB of disk available.
> >>
> >> fdisk shows this:
> >> # fdisk -p
> >> # /dev/mfid0
> >> g c364602 h255 s63
> >> p 1 0xa5 63 1562363771
> >> a 1
> >>
> >> When I run the fdisk editor in sysinstall I see this:
> >>
> >> Disk name: mfid0 FDISK Partition
> >> Editor
> >> DISK Geometry: 364602 cyls/255 heads/63 sectors =3D 5857331130 sectors
> >> (2860024MB)
> >>
> >> Offset Size(ST) End Name PType Desc Subtype
> >> Flags
> >>
> >> 0 63 62 - 12 unused 0
> >> 63 1562363771 1562363833 mfid0s1 8 freebsd 165
> >> 1562363834 4294981702 5857345535 - 12 unused 0
> >>
> >> I want to capture all that unused space and add it to the server.
> >>
> >> fstab has this:
> >> # cat /etc/fstab
> >> # Device Mountpoint FStype Options Dump
> >> Pass#
> >> /dev/mfid0s1b none swap sw 0=
0
> >> /dev/mfid0s1a / ufs rw 1=
1
> >> /dev/mfid0s1e /home ufs rw 2=
2
> >> /dev/mfid0s1d /tmp ufs rw 2=
2
> >> /dev/mfid0s1f /usr ufs rw 2=
2
> >> /dev/mfid0s1g /var ufs rw 2=
2
> >> /dev/acd0 /cdrom cd9660 ro,noauto 0 0
> >>
> >> When I try to create a new slice using fdisk, it doesn't seem to work.
> >
> > Did you try something like:
> >
> > echo "p 2 165 * *" | sudo fdisk -f- /dev/mfid0
> >
> > ??
>=20
> Thank you for your detailed and informative answer.
>=20
> I did not. I'm a neophyte in the disk world. I've always used sysinstall
> to setup partitions and mount points.
>=20
> >
> > Afterward "fdisk -p" should show something like...
> >
> ># /dev/mfid0
> > g c364602 h255 s63
> > p 1 0xa5 63 1562363771
> > p 2 0xa5 <num> <num>
> > a 1
> >
> > And then you'll have /dev/mfid0s2 which you can do-with what you like
> > (directly newfs the slice or create BSD partitions underneath that to
> > further sub-divide into as many as 8 smaller units, /dev/mfid0s2[a-h]).
> >
>=20
> I've been doing some more research on this problem, and I've discovered
> that bsdlabel has a 2 to the 32nd limit on disk size. It appears I have =
to
> use gpart instead. Is that not correct?
>=20
Only if your disk is larger than 2TB (or 2048GB). If you try to partition a=
>2TB disk with fdisk the most you can hope to access is 2TB (the rest will=
be forever unused).
I was noticing that that the total size for all your partitions is about 74=
4.95GB -- far short of the maximum addressable of 2TB. So you *could* gain =
access to more space with the tricks discussed here, but yes...
You will be required to use gpart to address more than 2TB of storage on a =
single discrete disk. gpart creates a GPT layout versus fdisk which creates=
an MBR layout. GPT uses length identifiers double that of MBR so you shoul=
d be able to address up to 16 million terabytes on any single discrete disk=
with gpart. That ought to be enough for a while (the largest storage array=
known to exist today is in the Petabytes ... thousands of terabytes -- nob=
ody has yet produced a single storage device of contiguous addressable spac=
e matching-or-exceeding 1024 petabytes or 1M terabytes; so we have a ways t=
o go before anybody reaches the limit of 2^64).
> >
> >> If I move to the label editor, I get this:
> >>
> >> FreeBSD Disklabel Editor
> >>
> >> Disk: mfid0 Partition name: mfid0s1 Free: 0 blocks (0MB)
> >>
> >> Part Mount Size Newfs Part Mount Size Ne=
wfs
> >> ---- ----- ---- ----- ---- ----- ---- --=
---
> >> mfid0s1a <none> 2000MB *
> >> mfid0s1d <none> 65536MB *
> >> mfid0s1e <none> 4096MB *
> >> mfid0s1b swap 65536MB SWAP
> >> mfid0s1f <none> 10240MB *
> >> mfid0s1g <none> 601GB *
> >>
> >> As you can see mfid0s1g is 601GB, and according to fstab that's /var.
> >>
> >> Yet df -h shows:
> >>
> >> # df -h
> >> Filesystem Size Used Avail Capacity Mounted on
> >> /dev/mfid0s1a 1.9G 726M 1.0G 41% /
> >> devfs 1.0k 1.0k 0B 100% /dev
> >> /dev/mfid0s1e 3.9G 38M 3.5G 1% /home
> >> /dev/mfid0s1d 62G 6.6M 57G 0% /tmp
> >> /dev/mfid0s1f 9.7G 7.5G 1.4G 84% /usr
> >> /dev/mfid0s1g 582G 39G 496G 7% /var
> >>
> >> So apparently I'm not creating this new slice? It should be
> >> /dev/mfid0s1h, correct?
> >>
> >
> > Let's not confuse slices (DOS partitions) with disklabels (BSD
> > partitions).
>=20
> OK. I've clearly done that. As I say, I'm a neophyte in the disk geomet=
ry
> and configuration field.
>=20
> >
> > DOS partitions are (maximum 4 per disk):
> >
> > mfid0s1
> > mfid0s2
> > mfid0s3
> > mfid0s4
> >
> > (according to your "fdisk -p" output, you're mfid0 disk is currently on=
ly
> > using mfid0s1)
> >
> > BSD partitions are (maximum 8 per "slice" aka DOS partition):
> >
> > mfid0s1a
> > mfid0s1b
> > mfid0s1c
> > mfid0s1d
> > mfid0s1e
> > mfid0s1f
> > mfid0s1g
> > mfid0s1h
> >
> > (according to your sysinstall output, you're mfid0s1 slice has 5 BSD
> > partitions -- a, e, d, f, and g)
> >
>=20
> I see.
>=20
> >
> >> How to I "recapture" the remaining 2+TB of space that's not being used?
> >>
> >
> > The easiest way to use your extra space is to not adjust one of those 5
> > BSD partitions, but instead create a new DOS partition (mfid0s2 as
> > previously discussed above). However, if you *really* want to "grow" an
> > existing BSD partition, this can be done (very carefully).
> >
>=20
> I'm all for taking the easy way out. :-)
>=20
^_^
>=20
> > First, you'll want to save the output of "disklabel -r mfid0s1" to a te=
xt
> > file.
> >
> > Next, you'll have to re-fdisk mfid0 so that the first slice covers the
> > entire disk. Of course, re-mastering the slices does not affect the dat=
a,
> > but it _will_ wipe out the BSD partition map (the disklabels; in other
> > words, after using fdisk to adjust the slice size of the first DOS
> > partition, "disklabel -r mfid0s1" will no longer return what it had
> > before -- you'll have no disklabels after), so the previous step of
> > backing up the output of "disklabel -r ..." is paramount.
> >
> > Next, you'll have to restore the disklabel (using "disklabel -e mfid0s1"
> > and cross-referencing your backup text file) with one slight adjustment=
...
> >
> > You're going to use the *exact* values you backed up _EXCEPT_ you're
> > going to make the last label (position-wise -- taking care to note the
> > byte ranges of each disklabel -- ignoring "c" which of course is a pseu=
do
> > label for "whole slice") bigger while keeping the same offset (only the
> > size of the last label should change).
> >
> > In your case, given the output you provided from sysinstall, this would
> > likely be your "g" label (but I'd have to see your "disklabel -r" output
> > to know for sure -- again, taking care to analyze the byte ranges).
> >
> > Once you've re-written the disklabels (making sure to change nothing fr=
om
> > your previous backup except the size of the last label to cover the new
> > unused space), you're now at a position where you can "grow" the label
> > with:
> >
> > growfs /dev/mfid0s1g
> >
> > NOTE: Should be done from a LiveFS (read: not while booted from said
> > filesystem).
> >
> > That will zero out the unused inodes and make the new space available.
> > Upon your next boot you'll now have the new storage space available to
> > your "g" label (/var from the looks of it).
> >
> > NOTE: If you wanted to change "g" to your "/usr" partition, rsync is yo=
ur
> > friend -- while booted from a LiveFS like DruidBSD or mfsBSD etc.).
>=20
> Excellent information. Thank you.
>=20
No problem, glad to help.
--=20
Devin
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