[SFS] mounting linux filesystem from local drives
Aaron Brown
aayore@gmail.com
Fri, 13 Jan 2017 09:09:39 -0700
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The UUID is a good suggestion. (Although this is all a bit silly since
the local /dev/sdb1 won't change on you.) You can run into a problem
with multipathed volumes when mounting by label, because it'll see
several volumes with the same label. There's a way around that, but I
don't remember what it is. You have to set a priority order somewhere.
> David L. Willson <mailto:dlwillson@sofree.us>
> January 13, 2017 at 8:49 AM
> Some thoughts:
> - I like UUID=... better than LABEL=... for specifying what to mount.
> It's even less likely to change or collide. You can discover the
> current label, UUID, and some other interesting things by running
> `blkid` against the device.
> - Editing fstab while the system is running is fine, iif you reboot or
> at least run `mount -av` to verify that you did what you meant. Doing
> it optimistically is a bad habit to get into.
> - Starting with LVM and the smallest reasonable logical volumes is a
> really good idea for machines that may be in service a long time.
> - Labeled filesystems should appear by label in /dev/disk/by-label/
> and not in /dev/mapper/.
>
> ```
> [dlwillson@intecrowd-vboxws ~]$ ls -l /dev/disk/by-label/
> total 0
> lrwxrwxrwx. 1 root root 9 Jan 13 08:20 VBOXADDITIONS_5.1.10_112026 ->
> ../../sr0
> [dlwillson@intecrowd-vboxws ~]$ ll /dev/mapper/
> total 0
> lrwxrwxrwx. 1 root root 7 Jan 13 08:19 centos-root -> ../dm-0
> lrwxrwxrwx. 1 root root 7 Jan 13 08:19 centos-swap -> ../dm-1
> crw-------. 1 root root 10, 236 Jan 13 08:19 control
> [dlwillson@intecrowd-vboxws ~]$ blkid /dev/dm-0
> /dev/dm-0: UUID="6e274ff6-a3a5-4d02-9ace-1f99c11158ed" TYPE="xfs"
> [dlwillson@intecrowd-vboxws ~]$
> ```
>
> --
> David L. Willson
> Teacher, Engineer, Evangelist
> RHCE+Satellite CCAH Linux+ LPIC-1 SUSE_CLP LFCS
> Mobile 720-333-LANS(5267)
> http://sofree.us
>
> This is a good time for a r3VOLution.
>
> ------------------------------------------------------------------------
> *From: *"Jed Walker" <jedwa@comcast.net>
> *To: *"Aaron Brown" <aayore@gmail.com>
> *Cc: *"sfs" <sfs@thegeek.nu>
> *Sent: *Thursday, January 12, 2017 9:04:11 PM
> *Subject: *RE: [SFS] mounting linux filesystem from local drives
>
> Yes, editing fstab while the system is running is fine, I've done that
> a ton. I was wondering about the xfs_admin command. If I have the time
> I'll that command and see what happens (and reply). I just can't
> afford to waste time fixing it since I have to get it to the DC Monday.
>
>
>
> Yes, I like LVM for adding more space but the drive bays are full so I
> figured it wouldn't be happening and we'll hopefully move off to a
> storage device for more space later.
>
> I appreciate all the help, and thanks for the article on LVM and
> performance.
>
> *From:*Aaron Brown [mailto:aayore@gmail.com]
> *Sent:* Thursday, January 12, 2017 7:03 PM
> *To:* Jed Walker
> *Cc:* 'sfs'
> *Subject:* Re: [SFS] mounting linux filesystem from local drives
>
> It's definitely fine to edit the fstab while the drive is online. It
> *should* be fine to provide a label with the drive online, but if
> you've got stuff you can't lose I'd advise testing somewhere else or
> unmounting the drive first. I'm really not sure if FS labels show up
> under /dev/mapper/. I think the label applies to the base block
> device, so I don't think device mapper will pick it up and put it in
> /dev/mapper/. Let me know what you find out. :)
>
>
> Also - There's really no downside to LVM. It doesn't impact storage
> performace
> (http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance)
> and it gives you a bunch of options that you might want in the
> future. If you ever start to run out of space, you could add a second
> RAID volume and use LVM to concatenate them together. If space isn't
> an issue, then you've got room for snapshots.
>
>
> Jed Walker wrote:
>
>
>
> Thank you Aaron. It is being use now, so can I run that while it is
> being used to give it a label, and then change the fstab and remount
> later? Also, when you say a "label" does that mean it will show as
> something like /dev/mapper/<label> ?
>
>
> *From:*Aaron Brown [mailto:aayore@gmail.com]
> *Sent:* Thursday, January 12, 2017 6:36 PM
> *To:* Jed Walker
> *Cc:* sfs
> *Subject:* Re: [SFS] mounting linux filesystem from local drives
>
>
> The local drives won't move around on you. They're not subjected to
> the same dynamic mapping that's incurred when you use remote disks.
> But if you're worried about it, you could mount by label. Just use
> `xfs_admin -L my_data_disk /dev/sdb1` to label the partition and use
> LABEL=my_data_disk in place of /dev/sdb1 your fstab.
>
>
> -Aaron
>
>
>
> *Jed Walker* <mailto:jedwa@comcast.net>
>
>
> January 12, 2017 at 6:29 PM
>
>
> I have a local disk (raid10) I mounted for storage in CentOS 7. From
> reading I believe there is no reason to put LVM on top and I can just
> partition and mount. So I figured I mount the filesystem directly on
> the partition.
>
>
> /etc/fstab, like:
>
>
> /dev/sdb1 /mydata xfs defaults,noatime 0 0
>
>
> This all worked fine and seems fine after reboot, but I got worried.
> This is not something I've done before since my experience is with big
> databases, thus I have only worked with mounting external LUNs from
> storage devices. On those I always use multipath and udev to associate
> them to the disks because the /dev/<dev> names can change on reboot.
>
>
>
> Is this not true with local drives? i.e. will the local drives always
> mount with the same name, thus my /etc/fstab above is valid?
>
>
> Thank you for your help,
>
>
> Jed
>
>
> Jed Walker <mailto:jedwa@comcast.net>
> January 12, 2017 at 9:04 PM
>
> Yes, editing fstab while the system is running is fine, I've done that
> a ton. I was wondering about the xfs_admin command. If I have the time
> I'll that command and see what happens (and reply). I just can't
> afford to waste time fixing it since I have to get it to the DC Monday.
>
>
>
> Yes, I like LVM for adding more space but the drive bays are full so I
> figured it wouldn't be happening and we'll hopefully move off to a
> storage device for more space later.
>
> I appreciate all the help, and thanks for the article on LVM and
> performance.
>
> *From:*Aaron Brown [mailto:aayore@gmail.com]
> *Sent:* Thursday, January 12, 2017 7:03 PM
> *To:* Jed Walker
> *Cc:* 'sfs'
> *Subject:* Re: [SFS] mounting linux filesystem from local drives
>
> It's definitely fine to edit the fstab while the drive is online. It
> *should* be fine to provide a label with the drive online, but if
> you've got stuff you can't lose I'd advise testing somewhere else or
> unmounting the drive first. I'm really not sure if FS labels show up
> under /dev/mapper/. I think the label applies to the base block
> device, so I don't think device mapper will pick it up and put it in
> /dev/mapper/. Let me know what you find out. :)
>
> Also - There's really no downside to LVM. It doesn't impact storage
> performace
> (http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance)
> and it gives you a bunch of options that you might want in the
> future. If you ever start to run out of space, you could add a second
> RAID volume and use LVM to concatenate them together. If space isn't
> an issue, then you've got room for snapshots.
>
> Jed Walker wrote:
>
>
> Thank you Aaron. It is being use now, so can I run that while it is
> being used to give it a label, and then change the fstab and remount
> later? Also, when you say a "label" does that mean it will show as
> something like /dev/mapper/<label> ?
>
> *From:*Aaron Brown [mailto:aayore@gmail.com]
> *Sent:* Thursday, January 12, 2017 6:36 PM
> *To:* Jed Walker
> *Cc:* sfs
> *Subject:* Re: [SFS] mounting linux filesystem from local drives
>
> The local drives won't move around on you. They're not subjected to
> the same dynamic mapping that's incurred when you use remote disks.
> But if you're worried about it, you could mount by label. Just use
> `xfs_admin -L my_data_disk /dev/sdb1` to label the partition and use
> LABEL=my_data_disk in place of /dev/sdb1 your fstab.
>
> -Aaron
>
>
> *Jed Walker* <mailto:jedwa@comcast.net>
>
> January 12, 2017 at 6:29 PM
>
> I have a local disk (raid10) I mounted for storage in CentOS 7. From
> reading I believe there is no reason to put LVM on top and I can just
> partition and mount. So I figured I mount the filesystem directly on
> the partition.
>
> /etc/fstab, like:
>
> /dev/sdb1 /mydata xfs defaults,noatime 0 0
>
> This all worked fine and seems fine after reboot, but I got worried.
> This is not something I've done before since my experience is with big
> databases, thus I have only worked with mounting external LUNs from
> storage devices. On those I always use multipath and udev to associate
> them to the disks because the /dev/<dev> names can change on reboot.
>
>
> Is this not true with local drives? i.e. will the local drives always
> mount with the same name, thus my /etc/fstab above is valid?
>
> Thank you for your help,
>
> Jed
>
> Aaron Brown <mailto:aayore@gmail.com>
> January 12, 2017 at 7:02 PM
> It's definitely fine to edit the fstab while the drive is online. It
> *should* be fine to provide a label with the drive online, but if
> you've got stuff you can't lose I'd advise testing somewhere else or
> unmounting the drive first. I'm really not sure if FS labels show up
> under /dev/mapper/. I think the label applies to the base block
> device, so I don't think device mapper will pick it up and put it in
> /dev/mapper/. Let me know what you find out. :)
>
> Also - There's really no downside to LVM. It doesn't impact storage
> performace
> (http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance)
> and it gives you a bunch of options that you might want in the
> future. If you ever start to run out of space, you could add a second
> RAID volume and use LVM to concatenate them together. If space isn't
> an issue, then you've got room for snapshots.
>
> Jed Walker wrote:
> Jed Walker <mailto:jedwa@comcast.net>
> January 12, 2017 at 6:51 PM
>
> Thank you Aaron. It is being use now, so can I run that while it is
> being used to give it a label, and then change the fstab and remount
> later? Also, when you say a "label" does that mean it will show as
> something like /dev/mapper/<label> ?
>
> *From:*Aaron Brown [mailto:aayore@gmail.com]
> *Sent:* Thursday, January 12, 2017 6:36 PM
> *To:* Jed Walker
> *Cc:* sfs
> *Subject:* Re: [SFS] mounting linux filesystem from local drives
>
> The local drives won't move around on you. They're not subjected to
> the same dynamic mapping that's incurred when you use remote disks.
> But if you're worried about it, you could mount by label. Just use
> `xfs_admin -L my_data_disk /dev/sdb1` to label the partition and use
> LABEL=my_data_disk in place of /dev/sdb1 your fstab.
>
> -Aaron
>
>
> *Jed Walker* <mailto:jedwa@comcast.net>
>
> January 12, 2017 at 6:29 PM
>
> I have a local disk (raid10) I mounted for storage in CentOS 7. From
> reading I believe there is no reason to put LVM on top and I can just
> partition and mount. So I figured I mount the filesystem directly on
> the partition.
>
> /etc/fstab, like:
>
> /dev/sdb1 /mydata xfs defaults,noatime 0 0
>
> This all worked fine and seems fine after reboot, but I got worried.
> This is not something I've done before since my experience is with big
> databases, thus I have only worked with mounting external LUNs from
> storage devices. On those I always use multipath and udev to associate
> them to the disks because the /dev/<dev> names can change on reboot.
>
>
> Is this not true with local drives? i.e. will the local drives always
> mount with the same name, thus my /etc/fstab above is valid?
>
> Thank you for your help,
>
> Jed
>
> Aaron Brown <mailto:aayore@gmail.com>
> January 12, 2017 at 6:36 PM
> The local drives won't move around on you. They're not subjected to
> the same dynamic mapping that's incurred when you use remote disks.
> But if you're worried about it, you could mount by label. Just use
> `xfs_admin -L my_data_disk /dev/sdb1` to label the partition and use
> LABEL=my_data_disk in place of /dev/sdb1 your fstab.
>
> -Aaron
>
>
--------------050309070607050602000101
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
<html><head>
<meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type">
</head><body bgcolor="#FFFFFF" text="#000000">The UUID is a good
suggestion. (Although this is all a bit silly since the local /dev/sdb1
won't change on you.) You can run into a problem with multipathed
volumes when mounting by label, because it'll see several volumes with
the same label. There's a way around that, but I don't remember what it
is. You have to set a priority order somewhere.<br>
<span>
</span><br>
<blockquote style="border: 0px none;"
cite="mid:1429324249.5878.1484322560549.JavaMail.zimbra@sofree.us"
type="cite">
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="width:100%;border-top:1px solid #EDEEF0;padding-top:5px"> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:49%;">
<a moz-do-not-send="true" href="mailto:dlwillson@sofree.us"
style="color:#737F92
!important;padding-right:6px;font-weight:bold;text-decoration:none
!important;">David L. Willson</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#9FA2A5"><span style="padding-left:6px">January
13, 2017 at 8:49 AM</span></font></div> </div></div>
<div style="color:#888888;margin-left:24px;margin-right:24px;"
__pbrmquotes="true" class="__pbConvBody"><div style="font-family: times
new roman, new york, times, serif; font-size: 12pt; color: #000000"><div>Some
thoughts:<br></div><div>- I like UUID=... better than LABEL=... for
specifying what to mount. It's even less likely to change or collide.
You can discover the current label, UUID, and some other interesting
things by running `blkid` against the device.<br></div><div>- Editing
fstab while the system is running is fine, iif you reboot or at least
run `mount -av` to verify that you did what you meant. Doing it
optimistically is a bad habit to get into.<br></div><div>- Starting with
LVM and the smallest reasonable logical volumes is a really good idea
for machines that may be in service a long time.</div><div>- Labeled
filesystems should appear by label in /dev/disk/by-label/ and not in
/dev/mapper/.<br></div><div><br></div><div>```<br></div><div><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">[dlwillson@intecrowd-vboxws
~]$ ls -l /dev/disk/by-label/</span><br><span style="font-family:
courier new,courier,monaco,monospace,sans-serif;">total 0</span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">lrwxrwxrwx.
1 root root 9 Jan 13 08:20 VBOXADDITIONS_5.1.10_112026 -> ../../sr0</span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">[dlwillson@intecrowd-vboxws
~]$ ll /dev/mapper/</span><br><span style="font-family: courier
new,courier,monaco,monospace,sans-serif;">total 0</span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">lrwxrwxrwx.
1 root root 7 Jan 13 08:19 centos-root -> ../dm-0</span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">lrwxrwxrwx.
1 root root 7 Jan 13 08:19 centos-swap -> ../dm-1</span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">crw-------.
1 root root 10, 236 Jan 13 08:19 control</span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">[dlwillson@intecrowd-vboxws
~]$ blkid /dev/dm-0</span><br><span style="font-family: courier
new,courier,monaco,monospace,sans-serif;">/dev/dm-0:
UUID="6e274ff6-a3a5-4d02-9ace-1f99c11158ed" TYPE="xfs" </span><br><span
style="font-family: courier new,courier,monaco,monospace,sans-serif;">[dlwillson@intecrowd-vboxws
~]$</span> <br>```<br></div><div><br></div><div><span name="x"></span>--<br>David
L. Willson<br>Teacher, Engineer, Evangelist<br>RHCE+Satellite CCAH
Linux+ LPIC-1 SUSE_CLP LFCS<br>Mobile 720-333-LANS(5267)<br><a class="moz-txt-link-freetext" href="http://sofree.us">http://sofree.us</a><br><div><br></div>This
is a good time for a r3VOLution.<span name="x"></span><br></div><div><br></div><hr
id="zwchr"><div data-mce-style="color: #000; font-weight: normal;
font-style: normal; text-decoration: none; font-family:
Helvetica,Arial,sans-serif; font-size: 12pt;"
style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From:
</b>"Jed Walker" <a class="moz-txt-link-rfc2396E" href="mailto:jedwa@comcast.net"><jedwa@comcast.net></a><br><b>To: </b>"Aaron Brown"
<a class="moz-txt-link-rfc2396E" href="mailto:aayore@gmail.com"><aayore@gmail.com></a><br><b>Cc: </b>"sfs" <a class="moz-txt-link-rfc2396E" href="mailto:sfs@thegeek.nu"><sfs@thegeek.nu></a><br><b>Sent:
</b>Thursday, January 12, 2017 9:04:11 PM<br><b>Subject: </b>RE: [SFS]
mounting linux filesystem from local drives<br><div><br></div><style><!--
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--></style><div class="WordSection1"><p class="MsoNormal"><span
data-mce-style="font-size: 11.0pt; font-family: 'Calibri','sans-serif';
color: #1f497d;"
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Yes,
editing fstab while the system is running is fine, I’ve done that a
ton. I was wondering about the xfs_admin command. If I have the time
I’ll that command and see what happens (and reply). I just can’t afford
to waste time fixing it since I have to get it to the DC Monday.</span></p><p
class="MsoNormal"><span data-mce-style="font-size: 11.0pt; font-family:
'Calibri','sans-serif'; color: #1f497d;"
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><br></span></p><div><br></div><p
class="MsoNormal"><span data-mce-style="font-size: 11.0pt; font-family:
'Calibri','sans-serif'; color: #1f497d;"
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Yes,
I like LVM for adding more space but the drive bays are full so I
figured it wouldn’t be happening and we’ll hopefully move off to a
storage device for more space later.</span></p><p class="MsoNormal"><span
data-mce-style="font-size: 11.0pt; font-family: 'Calibri','sans-serif';
color: #1f497d;"
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span></p><p
class="MsoNormal"><span data-mce-style="font-size: 11.0pt; font-family:
'Calibri','sans-serif'; color: #1f497d;"
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I
appreciate all the help, and thanks for the article on LVM and
performance.</span></p><p class="MsoNormal"><span
data-mce-style="font-size: 11.0pt; font-family: 'Calibri','sans-serif';
color: #1f497d;"
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span></p><div><div
data-mce-style="border: none; border-top: solid #B5C4DF 1.0pt; padding:
3.0pt 0in 0in 0in;" style="border:none;border-top:solid #B5C4DF
1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span
data-mce-style="font-size: 10.0pt; font-family: 'Tahoma','sans-serif';"
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span
data-mce-style="font-size: 10.0pt; font-family: 'Tahoma','sans-serif';"
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
Aaron Brown [<a class="moz-txt-link-freetext" href="mailto:aayore@gmail.com">mailto:aayore@gmail.com</a>] <br><b>Sent:</b> Thursday,
January 12, 2017 7:03 PM<br><b>To:</b> Jed Walker<br><b>Cc:</b> 'sfs'<br><b>Subject:</b>
Re: [SFS] mounting linux filesystem from local drives</span></p></div></div><p
class="MsoNormal"> </p><p class="MsoNormal">It's definitely fine to
edit the fstab while the drive is online. It *should* be fine to
provide a label with the drive online, but if you've got stuff you can't
lose I'd advise testing somewhere else or unmounting the drive first.
I'm really not sure if FS labels show up under /dev/mapper/. I think
the label applies to the base block device, so I don't think device
mapper will pick it up and put it in /dev/mapper/. Let me know what you
find out. :)<br></p><div><br></div><p class="MsoNormal">Also - There's
really no downside to LVM. It doesn't impact storage performace (<a
moz-do-not-send="true"
data-mce-href="http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance"
target="_blank"
href="http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance">http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance</a>)
and it gives you a bunch of options that you might want in the future.
If you ever start to run out of space, you could add a second RAID
volume and use LVM to concatenate them together. If space isn't an
issue, then you've got room for snapshots. <br></p><div><br></div><p
class="MsoNormal">Jed Walker wrote:<br></p><div><br></div><p
class="MsoNormal"><br>Thank you Aaron. It is being use now, so can I run
that while it is <br>being used to give it a label, and then change the
fstab and remount <br>later? Also, when you say a “label” does that
mean it will show as <br>something like /dev/mapper/<label> ?<br></p><div><br></div><p
class="MsoNormal">*From:*Aaron Brown [<a moz-do-not-send="true"
data-mce-href="mailto:aayore@gmail.com" target="_blank"
href="mailto:aayore@gmail.com">mailto:aayore@gmail.com</a>]<br>*Sent:*
Thursday, January 12, 2017 6:36 PM<br>*To:* Jed Walker<br>*Cc:* sfs<br>*Subject:*
Re: [SFS] mounting linux filesystem from local drives<br></p><div><br></div><p
class="MsoNormal">The local drives won't move around on you. They're
not subjected to <br>the same dynamic mapping that's incurred when you
use remote disks. <br>But if you're worried about it, you could mount by
label. Just use <br>`xfs_admin -L my_data_disk /dev/sdb1` to label the
partition and use <br>LABEL=my_data_disk in place of /dev/sdb1 your
fstab.<br></p><div><br></div><p class="MsoNormal">-Aaron<br></p><div><br></div><p
class="MsoNormal"><br>*Jed Walker* <<a moz-do-not-send="true"
data-mce-href="mailto:jedwa@comcast.net" target="_blank"
href="mailto:jedwa@comcast.net">mailto:jedwa@comcast.net</a>><br></p><div><br></div><p
class="MsoNormal">January 12, 2017 at 6:29 PM<br></p><div><br></div><p
class="MsoNormal">I have a local disk (raid10) I mounted for storage in
CentOS 7. From <br>reading I believe there is no reason to put LVM on
top and I can just <br>partition and mount. So I figured I mount the
filesystem directly on <br>the partition.<br></p><div><br></div><p
class="MsoNormal">/etc/fstab, like:<br></p><div><br></div><p
class="MsoNormal">/dev/sdb1 /mydata xfs defaults,noatime 0 0<br></p><div><br></div><p
class="MsoNormal">This all worked fine and seems fine after reboot, but
I got worried. <br>This is not something I’ve done before since my
experience is with big <br>databases, thus I have only worked with
mounting external LUNs from <br>storage devices. On those I always use
multipath and udev to associate <br>them to the disks because the
/dev/<dev> names can change on reboot.<br></p><div><br></div><p
class="MsoNormal"><br>Is this not true with local drives? i.e. will the
local drives always <br>mount with the same name, thus my /etc/fstab
above is valid?<br></p><div><br></div><p class="MsoNormal">Thank you for
your help,<br></p><div><br></div><p class="MsoNormal">Jed</p></div></div><div><br></div></div></div>
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
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<a moz-do-not-send="true" href="mailto:jedwa@comcast.net"
style="color:#737F92
!important;padding-right:6px;font-weight:bold;text-decoration:none
!important;">Jed Walker</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#9FA2A5"><span style="padding-left:6px">January
12, 2017 at 9:04 PM</span></font></div> </div></div>
<div style="color:#888888;margin-left:24px;margin-right:24px;"
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class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Yes,
editing fstab while the system is running is fine, I’ve done that a
ton. I was wondering about the xfs_admin command. If I have the time
I’ll that command and see what happens (and reply). I just can’t afford
to waste time fixing it since I have to get it to the DC Monday.<o:p></o:p></span></p><p
class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><br><br>Yes,
I like LVM for adding more space but the drive bays are full so I
figured it wouldn’t be happening and we’ll hopefully move off to a
storage device for more space later.<o:p></o:p></span></p><p
class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p><p
class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I
appreciate all the help, and thanks for the article on LVM and
performance.<o:p></o:p></span></p><p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p><div><div
style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in
0in"><p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
Aaron Brown [<a class="moz-txt-link-freetext" href="mailto:aayore@gmail.com">mailto:aayore@gmail.com</a>] <br><b>Sent:</b> Thursday,
January 12, 2017 7:03 PM<br><b>To:</b> Jed Walker<br><b>Cc:</b> 'sfs'<br><b>Subject:</b>
Re: [SFS] mounting linux filesystem from local drives<o:p></o:p></span></p></div></div><p
class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">It's definitely
fine to edit the fstab while the drive is online. It *should* be fine
to provide a label with the drive online, but if you've got stuff you
can't lose I'd advise testing somewhere else or unmounting the drive
first. I'm really not sure if FS labels show up under /dev/mapper/. I
think the label applies to the base block device, so I don't think
device mapper will pick it up and put it in /dev/mapper/. Let me know
what you find out. :)<br><br>Also - There's really no downside to LVM.
It doesn't impact storage performace (<a moz-do-not-send="true"
href="http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance">http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance</a>)
and it gives you a bunch of options that you might want in the future.
If you ever start to run out of space, you could add a second RAID
volume and use LVM to concatenate them together. If space isn't an
issue, then you've got room for snapshots. <br><br>Jed Walker wrote:<br><br><o:p></o:p></p><p
class="MsoNormal"><br>Thank you Aaron. It is being use now, so can I
run that while it is <br>being used to give it a label, and then change
the fstab and remount <br>later? Also, when you say a “label” does that
mean it will show as <br>something like /dev/mapper/<label> ?<br><br>*From:*Aaron
Brown [<a moz-do-not-send="true" href="mailto:aayore@gmail.com">mailto:aayore@gmail.com</a>]<br>*Sent:*
Thursday, January 12, 2017 6:36 PM<br>*To:* Jed Walker<br>*Cc:* sfs<br>*Subject:*
Re: [SFS] mounting linux filesystem from local drives<br><br>The local
drives won't move around on you. They're not subjected to <br>the same
dynamic mapping that's incurred when you use remote disks. <br>But if
you're worried about it, you could mount by label. Just use <br>`xfs_admin
-L my_data_disk /dev/sdb1` to label the partition and use <br>LABEL=my_data_disk
in place of /dev/sdb1 your fstab.<br><br>-Aaron<br><br><br>*Jed Walker*
<<a moz-do-not-send="true" href="mailto:jedwa@comcast.net">mailto:jedwa@comcast.net</a>><br><br>January
12, 2017 at 6:29 PM<br><br>I have a local disk (raid10) I mounted for
storage in CentOS 7. From <br>reading I believe there is no reason to
put LVM on top and I can just <br>partition and mount. So I figured I
mount the filesystem directly on <br>the partition.<br><br>/etc/fstab,
like:<br><br>/dev/sdb1 /mydata xfs defaults,noatime 0 0<br><br>This all
worked fine and seems fine after reboot, but I got worried. <br>This is
not something I’ve done before since my experience is with big <br>databases,
thus I have only worked with mounting external LUNs from <br>storage
devices. On those I always use multipath and udev to associate <br>them
to the disks because the /dev/<dev> names can change on reboot.<br><br><br>Is
this not true with local drives? i.e. will the local drives always <br>mount
with the same name, thus my /etc/fstab above is valid?<br><br>Thank you
for your help,<br><br>Jed<o:p></o:p></p></div></div>
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="width:100%;border-top:1px solid #EDEEF0;padding-top:5px"> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:49%;">
<a moz-do-not-send="true" href="mailto:aayore@gmail.com"
style="color:#737F92
!important;padding-right:6px;font-weight:bold;text-decoration:none
!important;">Aaron Brown</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#9FA2A5"><span style="padding-left:6px">January
12, 2017 at 7:02 PM</span></font></div> </div></div>
<div style="color:#888888;margin-left:24px;margin-right:24px;"
__pbrmquotes="true" class="__pbConvBody"><meta http-equiv="Content-Type"
content="text/html; charset=ISO-8859-1">It's definitely fine to edit
the fstab while the drive is online. It *should* be fine to provide a
label with the drive online, but if you've got stuff you can't lose I'd
advise testing somewhere else or unmounting the drive first. I'm really
not sure if FS labels show up under /dev/mapper/. I think the label
applies to the base block device, so I don't think device mapper will
pick it up and put it in /dev/mapper/. Let me know what you find out.
:)<br>
<br>
Also - There's really no downside to LVM. It doesn't impact storage
performace
(<a class="moz-txt-link-freetext" href="http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance">http://unix.stackexchange.com/questions/7122/does-lvm-impact-performance</a>)
and it gives you a bunch of options that you might want in the future.
If you ever start to run out of space, you could add a second RAID
volume and use LVM to concatenate them together. If space isn't an
issue, then you've got room for snapshots. <br>
<br>
Jed Walker wrote:<br>
</div>
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="width:100%;border-top:1px solid #EDEEF0;padding-top:5px"> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:49%;">
<a moz-do-not-send="true" href="mailto:jedwa@comcast.net"
style="color:#737F92
!important;padding-right:6px;font-weight:bold;text-decoration:none
!important;">Jed Walker</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#9FA2A5"><span style="padding-left:6px">January
12, 2017 at 6:51 PM</span></font></div> </div></div>
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class="MsoNormal"><span style="color:#1F497D">Thank you Aaron. It is
being use now, so can I run that while it is being used to give it a
label, and then change the fstab and remount later? Also, when you say a
“label” does that mean it will show as something like
/dev/mapper/<label> ?<o:p></o:p></span></p><p class="MsoNormal"><span
style="color:#1F497D"><o:p> </o:p></span></p><p class="MsoNormal"><span
style="color:#1F497D"><o:p> </o:p></span></p><div><div
style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in
0in"><p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
Aaron Brown [<a class="moz-txt-link-freetext" href="mailto:aayore@gmail.com">mailto:aayore@gmail.com</a>] <br><b>Sent:</b> Thursday,
January 12, 2017 6:36 PM<br><b>To:</b> Jed Walker<br><b>Cc:</b> sfs<br><b>Subject:</b>
Re: [SFS] mounting linux filesystem from local drives<o:p></o:p></span></p></div></div><p
class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">The local drives
won't move around on you. They're not subjected to the same dynamic
mapping that's incurred when you use remote disks. But if you're
worried about it, you could mount by label. Just use `xfs_admin -L
my_data_disk /dev/sdb1` to label the partition and use
LABEL=my_data_disk in place of /dev/sdb1 your fstab.<br><br>-Aaron<br><br><br><o:p></o:p></p><div
style="margin-left:18.75pt;margin-top:22.5pt;margin-right:18.75pt;margin-bottom:7.5pt"><div
style="border:none;border-top:solid #EDEEF0 1.0pt;padding:4.0pt 0in 0in
0in"><div><p style="vertical-align:middle" class="MsoNormal"><a
moz-do-not-send="true" href="mailto:jedwa@comcast.net"><b>Jed Walker</b></a><o:p></o:p></p></div><p
style="text-align:right;vertical-align:middle" class="MsoNormal"
align="right"><span style="color:#9FA2A5">January 12, 2017 at 6:29 PM</span><o:p></o:p></p></div></div><div
style="margin-left:.25in;margin-right:.25in"><p class="MsoNormal">I
have a local disk (raid10) I mounted for storage in CentOS 7. From
reading I believe there is no reason to put LVM on top and I can just
partition and mount. So I figured I mount the filesystem directly on the
partition. <o:p></o:p></p><p class="MsoNormal"> <o:p></o:p></p><p
class="MsoNormal">/etc/fstab, like:<o:p></o:p></p><p class="MsoNormal"><span
style="font-size:9.0pt;font-family:"Courier
New","serif"">/dev/sdb1 /mydata xfs defaults,noatime 0 0</span><o:p></o:p></p><p
class="MsoNormal"><span
style="font-size:9.0pt;font-family:"Courier
New","serif""> </span><o:p></o:p></p><p class="MsoNormal">This
all worked fine and seems fine after reboot, but I got worried. This
is not something I’ve done before since my experience is with big
databases, thus I have only worked with mounting external LUNs from
storage devices. On those I always use multipath and udev to associate
them to the disks because the /dev/<dev> names can change on
reboot.<o:p></o:p></p><p class="MsoNormal"><br>Is this not true with
local drives? i.e. will the local drives always mount with the same
name, thus my /etc/fstab above is valid?<o:p></o:p></p><p
class="MsoNormal"> <o:p></o:p></p><p class="MsoNormal">Thank you for
your help,<o:p></o:p></p><p class="MsoNormal"> <o:p></o:p></p><p
class="MsoNormal">Jed<o:p></o:p></p><p class="MsoNormal"><span
style="font-size:9.0pt;font-family:"Courier
New","serif""> </span><o:p></o:p></p></div><p
class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times
New Roman","serif""><o:p> </o:p></span></p></div></div>
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="width:100%;border-top:1px solid #EDEEF0;padding-top:5px"> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:49%;">
<a moz-do-not-send="true" href="mailto:aayore@gmail.com"
style="color:#737F92
!important;padding-right:6px;font-weight:bold;text-decoration:none
!important;">Aaron Brown</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#9FA2A5"><span style="padding-left:6px">January
12, 2017 at 6:36 PM</span></font></div> </div></div>
<div style="color:#888888;margin-left:24px;margin-right:24px;"
__pbrmquotes="true" class="__pbConvBody">
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
The local drives won't
move around on you. They're not subjected to the same dynamic mapping
that's incurred when you use remote disks. But if you're worried about
it, you could mount by label. Just use `xfs_admin -L my_data_disk
/dev/sdb1` to label the partition and use LABEL=my_data_disk in place of
/dev/sdb1 your fstab.<br>
<br>
-Aaron<br>
<span>
</span><br>
<br>
</div>
</blockquote>
<br>
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