[olug] The "other" raid utility usage

[Jay Swackhamer]

The LVM resizing works online if you have the online tools.

I have been using/resizing filesystems for a while. The LVM
implementation is so similar to HPUX that my scripts work
with minor modifications.........

(So what I need to do is setup two filesystems striped
across four drives, then mirror them...........or just
stripe across all eight and have 250x8=2TB, because I'd
probably need more space.....)

> On Wed, 23 Apr 2003, Daniel G. Linder wrote:
>
>> Matthew, or anyone else for that matter,
>>
>>   Has anyone ever tried the filesystem resize "stuff"?  I know that EXT2
>>   has some hooks to allow for a filesystem to be resized, but do I have
>>   to un-mount that filesystem to do this, or can I do it on the fly (if
>>   I have space on the HDD)?  Here is what lead to this question:
>
> Supposedly you can add space on the fly. I have not tried it meself. At
> LinuxWorld in 2001 I heard Ted T'so talk about using a patch to mke2fs for
> this but I never really followed up.
>
> Your best bet it to use LVM (pick one they are all pretty much the same
> although I am partial to IBM's) to create the filesystem. Note that LVM
> can create and manipulate filesystem partitions on raid (MD)  devices. LVM
> will allow you to merge, split, and do loads of wierd things to the
> filesystems. You can even mirror two logical partitions (filesystems)
> themselves...
>
>>   Say I am fortunate enough to have a hot-swappable RAID array with five
>>   18GB HDDs setup in RAID-5 using 100% of the HDD space.  Years go by,
>>   and as drives fail, I replace them but since prices have come down I
>>   purchase 36GB HDDs and just leave the remainder un-formatted.  Once
>>   all five HDD's have been replaced, I *could* then expand the
>>   filesystem and get double the space without rebuilding the
>>   partition...  If this were an extremely critical system -- i.e.
>>   99.999% uptime is not good enough :) -- then doing the expansion on
>>   the fly would be really cool and a big shot in the arm for Linux. :D
>
> Ooog - I would definately only want to try this with LVM - especially on
> "critical" filesystems.
>
>> Dan
>> (Just trying to scrape together enough $$$ for a *single* larger HDD...
>> :( )
>
> Yeah - funny thing is I could have bought three 200M IDE drives for the
> price of the SCSI rack unit but I trust the SCSI rack to be running long
> after the IDE's have been in the landfill... O'course that is probably
> just my ancient wheezing take on this newfangled stuff... ;-}
>
> Hmmm - if lug ever holds a meeting I can make maybe we can try to put
> together a demo of mdadm and LVM in action. Could be fun...
>
> --------------------------------------------------
> Matthew G. Marsh,  President
> Paktronix Systems LLC
> 1506 North 59th Street
> Omaha  NE  68104
> Phone: (402) 553-2288
> Email: mgm at midwestlinux.com
> WWW:  http://www.midwestlinux.com
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-- 

Jay Swackhamer
Reboot The User
15791 West Dodge Rd
Suite 135
Omaha, NE 68118
(402) 933-6449
http://www.RebootTheUser.com