From: "George Spelvin" <linux@horizon.com>
To: linux@horizon.com, tytso@mit.edu
Cc: linux-ext4@vger.kernel.org
Subject: Re: 64bit + resize2fs... this is Not Good.
Date: 14 Nov 2012 22:43:03 -0500 [thread overview]
Message-ID: <20121115034303.3956.qmail@science.horizon.com> (raw)
In-Reply-To: <20121114233854.GD24980@thunk.org>
> It's actually not 1000x times. It's a 1000x times up to a maximum of
> 1024 current and reserved gdt blocks (which is the absolute maxmimum
> which can be supported using resize_inode feature). Contrary to what
> you had expected, it's simply not possible to have 2048 or 4096
> reserved gdt blocks using the resize_inode scheme. That's because it
> stores in the reserved gdt blocks using an indirect/direct scheme, and
> that's all the sapce that we have. (With a 4k block, and 4 bytes per
> blocks --- the resize_inode scheme simply completely doesn't work if
> above 16TB since it uses 4 byte block numbers --- 4k/4 = 1024 block group
> descriptors.)
Er... you can't use extents? The blocks *are* all contiguous.
>> Yeah, I see how that would cause problems, as you ask for 51.5G of
>> resize range. What pisses me off is that I asked for 64 TiB!
>> (-E resize=17179869184)
> Yes, mke2fs should have issued an error message to let you know
> there's no way it could honor your request.
As long as I get to be at least a *little* bit grumpy that *both*
mke2fs and resize2fs, when asked to do something they couldn't to,
failed to produce any sort of error message, but silently f***ed it up.
> Again, I'm really sorry; you were exploring some of the less well
> tested code paths in e2fsprogs/resize2fs. :-(
I seem to be developing a knack for that this last couple of months. :-(
I *thought* I was doing the obvious thing.
All I set out to do was expand a 10 TB RAID to 22 TB.
Really, everything I did I *thought* I chose the *safest*
possible option.
1. Restripe RAID
2. Try to resize FS, hit 16 TB limit.
3. Restripe RAID back down.
4. Create new 8 TB RAID from new drives
5. Format with 64-bit ext4, telling mke2fs that I will be resizing later.
5a. Fight with bug in mke2fs while doing so.
6. Copy over files from 32-bit FS
7. Destroy old RAID, and add drives to new RAID
8. Restripe up to 22 TB (again!)
9. Resize file system. Personally, an off-line technique
"feels safer" than on-line, so I went with that.
10. Kablooie!
Other than skipping the first 3 steps, what was I supposed to
do different?
next prev parent reply other threads:[~2012-11-15 3:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-14 3:51 64bit + resize2fs... this is Not Good George Spelvin
2012-11-14 5:43 ` Theodore Ts'o
2012-11-14 6:42 ` George Spelvin
2012-11-14 7:12 ` George Spelvin
2012-11-14 7:20 ` George Spelvin
2012-11-14 20:39 ` Theodore Ts'o
2012-11-14 21:04 ` Theodore Ts'o
2012-11-14 23:26 ` George Spelvin
2012-11-14 23:38 ` Theodore Ts'o
2012-11-15 3:43 ` George Spelvin [this message]
2012-11-14 6:27 ` George Spelvin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121115034303.3956.qmail@science.horizon.com \
--to=linux@horizon.com \
--cc=linux-ext4@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).